WO2023197124A1 - Apparatus for testing surface state of sample to be tested - Google Patents

Abstract

The present application provides an apparatus and method for testing a surface state of a sample to be tested, and a chemical mechanical polishing device. The apparatus for testing a surface state of a sample to be tested comprises a light source assembly, a first concave spherical mirror, a second concave spherical mirror and an optical sensor. The light source assembly emits multiple light rays with different angles of emergence from a first incident focal point of the first concave spherical mirror, the sample to be tested is located at a first emergent focal point of the first concave spherical mirror, a second incident focal point of the second concave spherical mirror coincides with the first emergent focal point, and the optical sensor is located on a second emergent focal point of the second concave spherical mirror. Light rays with different angles of emergence are emitted and incident on the sample by means of the first concave spherical mirror, so that the light rays used for testing the surface state of the sample have multiple angles of incidence, thereby generating reflected light rays with multiple changes in intensity. Compared with light rays with a single angle of incidence, the measurement error can be reduced.

Description

Device for detecting the surface condition of the sample to be tested Technical field

The present application relates to the field of semiconductor manufacturing, and specifically to a device for detecting the surface state of a sample to be tested, a detection method thereof, and chemical mechanical grinding equipment.

Background technique

Optical detection has been widely used in the field of industrial manufacturing. For example, in the production process of high-precision products, the reflection or diffraction characteristics of light are usually used to detect sample defects; or in the use of chemical mechanical polishing to grind wafers. During the production process, the reflection characteristics of light are usually used to detect the grinding process of the sample to be tested, and then the detection results are used to adjust the grinding process or determine the grinding end point. Chemical mechanical polishing systems often include but are not limited to laser reflection sensors, optical sensors, eddy current sensors, motor torque sensors, ultrasonic sensors, white light interferometers, spectral confocal rangefinders, and some back-end closed-loop control systems, zoned pressure control, and rotational speed. And grinding liquid flow rate adjustment, etc., this system is a necessary condition to ensure the quality of chemical mechanical grinding samples.

Among them, the laser reflection sensor and optical sensor of the above system are non-contact detection methods. Because of their fast detection speed and non-contact characteristics, they are very suitable for in-situ detection scenarios. In-situ detection means that there is no need to move the sample being tested. , detected during the grinding process. The detection principle is to carry surface information of the sample to be measured through reflected light, such as the reflection intensity of the metal surface or dielectric layer. By using an optical sensor to identify the relative intensity change of the reflected light, the object to be measured can be identified. Some key information on the surface. In the prior art, a plane mirror is used to reflect light into the sample to be tested. A plane mirror can only reflect light at one incident angle to the sample to be tested. That is to say, the incident angle of the light used to detect the sample to be tested is single. A single angle. Light may cause errors in judgment; in addition, when there are some patterned metal traces or dielectric patterns on the sample to be tested, the size of the patterned metal or dielectric is relatively small, and the light at this incident angle is When diffraction occurs on its surface, it will also cause errors in judgment.

Contents of the invention

This application provides a device that uses multiple light rays at multiple incident angles to detect the surface state of a sample to be measured, which can effectively reduce judgment errors.

In a first aspect, this application provides a device for detecting the surface state of a sample to be tested. The device for detecting the surface state of a sample to be tested includes:

A light source component, the light source component is used to emit multiple light rays with different exit angles;

A first concave spherical mirror, the light emission position of the light source assembly is located at the first incident focus position of the first concave spherical mirror, and the sample to be measured is located at the first exit focus of the first concave spherical mirror;

a second concave spherical mirror, the second incident focus of the second concave spherical mirror coincides with the first exit focus of the first concave spherical mirror;

An optical sensor is located at the second exit focus of the second concave spherical mirror.

The device for detecting the surface state of the sample to be tested provided by this application uses a light source component to emit multiple light rays with different exit angles, and the light is incident on the sample to be tested through the first concave spherical mirror, so that the light incident on the sample to be tested is Light is light with multiple different incident angles. When the surface state of the sample to be tested changes, it will produce reflected light with multiple different intensity changes. That is to say, the light used to detect the surface state of the sample to be tested has multiple incidences. Angle, thereby generating reflected light with multiple intensity changes. The intensity change of the emitted light can reflect the surface state of the sample to be measured. The average of the multiple intensity change values of the multiple light rays is used to determine the light intensity compared with a single incident angle. The intensity change value can reduce the measurement error; and these multiple reflected light beams with different intensity changes are incident on the second concave spherical mirror, and then are converged and reflected to the optical sensor. That is to say, only one optical sensor can obtain multiple Reflected light with different intensity changes can save space and simplify the processing circuit.

In a possible implementation, the light source assembly includes a light source and an emission auxiliary component, the emission auxiliary component being used to incident the light emitted by the light source into the first concave spherical mirror in a preset angle range.

In a possible implementation, the emission auxiliary component is an optical fiber, the light source is located at the first end of the optical fiber, and the light emitted by the light source is incident into the optical fiber from the first end of the optical fiber, The second end of the optical fiber is the light exit end of the light source assembly. The second end of the optical fiber is located at the first incident focus position of the first concave spherical mirror. The light incident on the optical fiber is emitted from the optical fiber. The second end emerges onto the first concave spherical mirror.

In a possible implementation, the light source assembly further includes a beam expander, the beam expander is located between the second end of the optical fiber and the first concave spherical mirror, and the beam expander is used to The light emitted from the second end of the optical fiber diverges to have the preset angle range.

In a possible implementation, the light source assembly further includes an optical coupler, the optical coupler is located between the light source and the first end of the optical fiber, and is used to couple the light emitted by the light source into The optical fiber.

In a possible implementation, the light source assembly further includes an optical filter, the optical filter is located between the light source and the first end of the optical fiber, and is used to filter the light emitted by the light source. , so that the light coupled into the optical fiber is light with a specific wavelength.

In a possible implementation, the emission auxiliary component is a light emitting component, the light emitting component is located between the light source and the first concave spherical mirror, the light emitting component is provided with a light emitting hole, and the light emitting hole is the light exit position of the light source assembly, the light exit hole is located at the first incident focus position of the first concave spherical mirror, and the part of the light exit component other than the light exit hole is used to block the light from the light source.

In a possible implementation, the light emitting component is one of a light emitting plate or a light emitting cover.

In a possible implementation, the light outlet hole is a through hole that penetrates the light outlet component.

In a possible implementation, the light outlet hole includes a through hole penetrating the light outlet component and a light-transmitting material filled in the through hole.

In a possible implementation, the first concave spherical mirror and the second concave spherical mirror have an integrated structure.

In a possible implementation, the first concave spherical mirror and the second concave spherical mirror are independent components.

In a possible implementation, the device for detecting the surface state of the sample to be measured also includes a processing circuit, the processing circuit is electrically connected to the optical sensor, and the processing circuit is used to obtain information based on the optical sensor. Use light to determine the surface condition of the sample to be tested. Optical sensors include but are not limited to PD, APD, CCD or CMOS sensors. Processing circuits include amplifier circuits, analog-to-digital conversion circuits, and calculation circuits.

In a second aspect, the present application provides a chemical mechanical polishing equipment. The chemical mechanical polishing equipment includes a polishing pad and a device for detecting the surface state of a sample to be tested as described in any one of the above. The device for measuring the surface condition of the sample is located below the polishing pad, and the polishing pad is used to carry the sample to be tested.

In a possible implementation, the chemical mechanical polishing equipment further includes a grinding support column, and the polishing pad is located above the grinding support column.

In a possible implementation, the polishing pad includes a detection window that can transmit light, and the light reflected from the first concave spherical mirror passes through the detection window and is incident on the sample to be tested. .

In a possible implementation, the sample to be tested is a wafer.

In a possible implementation, the chemical mechanical polishing equipment further includes a grinding fluid for infiltrating the surface of the sample to be tested. By using the grinding action of nanoparticles in the grinding fluid, a smooth surface is formed on the surface of the ground sample to be tested.

In a possible implementation, the chemical mechanical polishing equipment further includes a polishing head for pressing the sample to be tested.

In a third aspect, this application also provides a method for detecting the surface state of a sample to be tested. The method for detecting the surface state of a sample to be tested includes:

Use a light source component to emit multiple light rays with different exit angles;

The plurality of light rays with different exit angles emitted by the light source assembly are incident on the first concave spherical mirror from a first incident focus position, wherein the light emission position of the light source assembly is located on the first side of the first concave spherical mirror. At the incident focus position;

Use the first concave spherical mirror to reflect the light onto the sample to be measured, wherein the sample to be measured is located at the first exit focus of the first concave spherical mirror;

The light reflected by the sample to be measured is reflected to the optical sensor through the second concave spherical mirror, wherein the second incident focus of the second concave spherical mirror coincides with the first exit focus of the first concave spherical mirror, and the optical sensor The sensor is located at the second exit focus of the second concave spherical mirror.

In a possible implementation, the method for detecting the surface state of the sample to be tested further includes:

The optical sensor transmits the received light to a processing circuit;

The processing circuit determines the surface state of the sample to be tested based on the light.

In a possible implementation, the light source component is used to emit multiple light rays with different exit angles, including:

using said light source to emit light;

The light emitted by the light source is incident on the first concave spherical mirror in a preset angle range using an emission auxiliary component.

In a possible implementation, the use of a light source component to emit multiple light rays with different exit angles also includes:

A beam expander is used to spread the light emitted from the emission auxiliary part to have the preset angle range, and the beam expander is located between the emission auxiliary part and the first concave spherical mirror.

In a possible implementation, the sample to be tested is a wafer.

In a possible implementation, the use of a light source component to emit multiple light rays with different exit angles also includes:

A beam expander is used to spread the light emitted from the emission auxiliary part to a preset angle range, and the beam expander is located between the emission auxiliary part and the first concave spherical mirror.

In a possible implementation, the use of a light source component to emit multiple light rays with different exit angles also includes:

An optical coupler is used to couple the light emitted by the light source into the optical fiber.

Description of the drawings

Figure 1 is a schematic structural diagram of chemical mechanical grinding equipment provided by an embodiment of the present application;

Figure 2 is a schematic structural diagram of a device for detecting the surface state of a sample to be tested according to an embodiment of the present application;

Figure 3 is a schematic structural diagram of light incident on the sample to be tested in a device for detecting the surface state of a sample to be tested according to an embodiment of the present application;

Figure 4 is a schematic structural diagram of light incident on the sample to be tested in a device for detecting the surface state of a sample to be tested according to an embodiment of the present application;

Figure 5 is a schematic structural diagram of a device for detecting the surface state of a sample to be tested in the prior art;

Figure 6 is a schematic diagram of the positions of optical fibers and beam expanders in a device for detecting the surface state of a sample to be tested according to an embodiment of the present application;

Figure 7 is a schematic structural diagram of a device for detecting the surface state of a sample to be tested according to an embodiment of the present application;

Figure 8 is a schematic structural diagram of a light source and a light-emitting component in a device for detecting the surface state of a sample to be tested according to an embodiment of the present application;

Figure 9 is a schematic structural diagram of a light source and a light-emitting component in a device for detecting the surface state of a sample to be tested according to an embodiment of the present application;

Figure 10 is a schematic structural diagram of a light source and a light-emitting component in a device for detecting the surface state of a sample to be tested according to an embodiment of the present application;

Figure 11 is a schematic diagram of the positions of the light source, the light output component and the beam expander in a device for detecting the surface state of a sample to be tested according to an embodiment of the present application;

Figure 12 is a schematic structural diagram of a device for detecting the surface state of a sample to be tested according to an embodiment of the present application;

Figure 13 is a schematic flow chart of a method for detecting the surface state of a sample to be tested according to an embodiment of the present application;

Figure 14 is a sub-flow chart of step S100 of the present application.

Detailed ways

Herein, the terms “first”, “second”, etc. are used for descriptive purposes only and shall not be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, features defined as "first" and "second" may explicitly or implicitly include one or more of these features. In the description of this application, unless otherwise stated, "plurality" means two or more.

In addition, in this article, directional terms such as "upper" and "lower" are defined relative to the schematic placement of the structure in the drawings. It should be understood that these directional terms are relative concepts and they are used relative to descriptions and clarifications, which may change accordingly depending on the orientation in which the structure is placed.

To facilitate understanding, the English abbreviations and related technical terms involved in the embodiments of the present application are first explained and described below.

PD: Photo Diode, photodiode.

APD: Avalanche Photo Diode, avalanche photodiode.

CCD: Charge Coupled Device.

CMOS sensor: complementary metal oxide semiconductor sensor.

LED: light-emitting diode, light-emitting diode.

This application provides a device for detecting the surface state of the sample to be tested, which can be used in chemical mechanical grinding equipment to detect the grinding end point of the sample to be tested. The device for detecting the surface state of the sample to be tested includes a light source. component, a first concave spherical mirror, a second concave spherical mirror and an optical sensor, wherein the light source component is used to emit multiple light rays with different exit angles. The light emission position of the light source component is located at the first incident focus of the first concave spherical mirror. The sample to be measured Located at the first exit focus of the first concave spherical mirror, the second incident focus of the second concave spherical mirror coincides with the first exit focus of the first concave spherical mirror, and the optical sensor is located at the second exit focus of the second concave spherical mirror. A plurality of light rays with different exit angles are emitted through the light source component, and the light rays are incident on the sample to be tested through the first concave spherical mirror, so that the light rays incident on the sample to be tested are light rays with multiple different incident angles, and are then passed through the sample in sequence. The measured sample and the second concave spherical mirror reflect and then enter the optical sensor. That is to say, the light used to detect the surface state of the sample to be measured has multiple incident angles, thereby generating reflected light with multiple intensity changes. The intensity of the reflected light changes. It can reflect the status of the sample to be measured, and use the average of multiple intensity change values of multiple light rays to determine the intensity change value compared to a single incident angle of light, which can reduce measurement errors.

Please refer to Figure 1. One embodiment of the present application provides a chemical mechanical polishing equipment 1. The chemical mechanical polishing equipment 1 includes a device 10 for detecting the surface state of a sample to be tested, a sample to be tested 20 and a polishing pad 30. The device 10 for measuring the surface condition of the sample is located below the polishing pad 30 . The polishing pad 30 is used to carry the sample 20 to be measured. The sample 20 to be measured is located above the polishing pad 30 . In this embodiment, the chemical mechanical polishing equipment 1 also includes a grinding support column 40. The polishing pad 30 is located above the grinding support column 40. There is a receiving space below the polishing pad 30. The device 10 for detecting the surface state of the sample to be tested is located In the accommodation space below the polishing pad 30 . In this embodiment, the sample 30 to be tested is a wafer. Generally, the wafer includes multiple dielectric layers and multiple metal layers. During the chemical mechanical polishing process, one metal layer needs to be removed to expose the dielectric layer; or one of the metal layers needs to be removed. One dielectric layer exposes another dielectric layer; or one metal layer is removed to expose another metal layer. When one of the materials is removed to expose another material in the chemical mechanical polishing method, it is called the grinding end point. In this embodiment, the surface state of the sample 20 to be tested refers to the surface material of the sample 20 to be tested.

In this embodiment, the polishing pad 30 includes a detection window 31 that can transmit light. The light reflected from the first concave spherical mirror 200 in the device 10 for detecting the surface state of the sample to be tested is incident through the detection window 31 to the sample 20 to be tested. The polishing pad 30 can be made of polymer material, such as polyurethane, and the detection window 31 can be made of light-transmitting material.

The chemical mechanical polishing equipment 1 further includes a polishing liquid 50 . During polishing, the polishing liquid 50 is dropped onto the polishing pad 30 and flows between the wafer 20 and the polishing pad 30 . When light passes through the detection window 31 and is incident on the surface of the wafer 20 facing the polishing pad 30 , the reflection intensity of the light is affected by the surface material of the polishing fluid and the sample 20 to be tested and the incident angle. The material of the polishing fluid and the incident angle remain unchanged. In the case of It is judged that the grinding end point has been reached and no further grinding is required at this time. Using the device 10 for detecting the surface state of the sample to be tested in this application, the light source assembly 100 is used to emit multiple light rays with different exit angles, and the light rays are incident on the sample to be tested 20 through the first concave spherical mirror 200, so that The light incident on the sample 20 to be tested is light with multiple different incident angles. When the surface material of the sample 20 to be tested changes, multiple reflected light rays with different intensity changes will be generated. These multiple reflected light rays with different intensity changes will be generated. After being incident on the second concave spherical mirror 300, it is reflected into the optical sensor 400. That is to say, the light used to reflect the interface material of the sample 20 to be tested has multiple incident angles, and thus has multiple reflected light changes in intensity. The average value of the multiple intensity change values of the multiple light rays is used to determine the comparison. The intensity change value of light at a single incident angle can reduce measurement errors.

It should be noted that the specific structural components of the chemical mechanical polishing equipment 1 in this application are not limited to the structure shown in Figure 1, and may also include more structural components to achieve specific functions in the chemical mechanical polishing process. For example, it may also include a polishing head for pressing the sample 20 to be tested.

It should also be noted that the sample 20 to be tested is not limited to wafers. As long as one of the materials is removed during the grinding process to expose the other material, the device 10 for detecting the surface state of the sample to be tested can be used. Detect grinding end point.

It should also be noted that the surface state of the sample to be tested 20 is not limited to the surface material, but may also include the surface texture or fine structure of the sample to be tested 20 . The fine structure includes protrusions, depressions, scratches, foreign matter, cracks, etc. When light is incident on the surface of the sample 20 to be measured, if the surface texture or surface fine structure is different, the intensity of the light after reflection on the surface will also be different, and thus reflected light intensity information reflecting the surface texture or fine structure can be obtained.

When used to detect the surface texture or fine structure of the sample to be tested 20, the device 10 for detecting the surface state of the sample to be tested can be used to detect product defects or yield, for example, to detect protrusions on the surface of the product 20. , dents, scratches, foreign objects and cracks and other defects. For example, assuming that there are 100 samples that need to be tested, the light information of the standard sample can be obtained in advance through the device 10 of the present application for detecting the surface state of the sample to be tested, and then the light information of the 100 samples to be tested 20 can be detected. When the light information of the measured sample 20 is different from the light information of the standard sample or the difference is greater than a preset range, it is determined to be a defective sample; otherwise, it is a qualified sample, and the product yield can be calculated. In this application, multiple light rays with different exit angles are emitted, and the light rays are incident on the sample to be tested 20 through the first concave spherical mirror 200, so that the light rays incident on the sample to be tested 20 have multiple different incident angles. Light, when the surface texture or fine structure of the sample to be tested 20 is different from the standard sample, a plurality of reflected light rays with different intensity changes will be generated. After these multiple reflected light rays with different intensity changes are incident on the second concave spherical mirror 300, they will be reflected by the second concave spherical mirror 300. Reflected into the optical sensor 400, the intensity change value of the light rays at a single incident angle is determined by averaging the intensity change values of the multiple rays of light, thereby reducing the measurement error.

The device 10 for detecting the surface state of the sample to be tested is introduced in detail below.

Please refer to FIG. 2 . An embodiment of the present application provides a device 10 for detecting the surface state of a sample to be tested. The device 10 for detecting the surface state of a sample to be tested includes a light source assembly 100 , a first concave spherical mirror 200 , a second concave spherical mirror 200 , and a second concave spherical mirror 200 . Spherical mirror 300 and optical sensor 400.

Among them, the light source component 100 is used to emit multiple light rays with different exit angles. That is to say, the exit angle of the light rays emitted from the light source component 100 is not one angle value, but has multiple angle values, or the emitted light rays are fan-shaped. , the sector has a certain angle range.

The light emission position of the light source assembly 100 is located at the first incident focus 210 of the first concave spherical mirror 200 , and the sample 20 to be tested is located at the first exit focus 220 of the first concave spherical mirror 200 . The light emitted from the first incident focus 210 will be reflected and converged to the first exit focus 220 after being incident on the first concave spherical mirror 200. Since the emitted light has multiple exit angles, the light incident on the first concave spherical mirror 200 will also be reflected. With multiple angles of incidence. In this application, the first incident focus 210 refers to the incident focus where the light rays are incident on the first concave spherical mirror 200 with the same focus, and the first exit focus 220 refers to the focus where the light rays converge after being reflected by the first concave spherical mirror 200. For the first concave spherical mirror 200, the first incident focus 210 and the first exit focus 220 are adapted to each other. The same first concave spherical mirror 200 has multiple first incident focus points 210 and multiple first exit focus points matching them. 220. Wherein, the sample 20 to be measured is located at the first exit focus 220 means that the focus point of the light after passing through the detection window 31 falls on the surface of the sample 20 to be measured facing the detection window 31, as long as the first exit focus 220 is located at the detection window 31. The area on the surface of sample 20 that needs to be detected is sufficient.

Wherein, if the curvature of the first concave spherical mirror 200 is different, the positions of the first incident focus 210 and the first exit focus 220 will also be different. In this application, the light emission position and the placement position of the sample 20 to be measured can be determined in advance, and then the first concave spherical mirror 200 with appropriate curvature can be selected; the first concave spherical mirror 200 with a curvature can also be selected first, and then the first concave spherical mirror can be adjusted by adjusting the first concave spherical mirror 200 . 200, the light emitting position, and the sample to be tested 20 are placed so that the light emitting position is located at the first incident focus 210 and the sample 20 to be measured is located at the first exit focus 220.

The second incident focus 310 of the second concave spherical mirror 300 coincides with the first exit focus 220 of the first concave spherical mirror 200 . Multiple light rays with different exit angles will be incident on the sample to be measured 20 at multiple different incident angles, and then reflected from the sample to be measured 20 to the second concave spherical mirror 300 at multiple different reflection angles. The optical sensor 400 is located at the second exit focus 320 of the second concave spherical mirror 300 . The light incident on the second concave spherical mirror 300 also has multiple incident angles, is reflected by the second concave spherical mirror 300 and then converges into the optical sensor 400 .

In this application, the second incident focus 310 refers to the incident focus where the light rays are incident on the second concave spherical mirror 300 with the same focus, and the second exit focus 320 refers to the focus where the light rays converge after being reflected by the second concave spherical mirror 300. For the second concave spherical mirror 300, the second incident focus 310 and the second exit focus 320 are adapted to each other. The same second concave spherical mirror 300 has multiple second incident focus points 310 and multiple second exit focus points matching them. 320. The fact that the optical sensor 400 is located at the second exit focus 320 of the second concave spherical mirror 300 means that the convergence point of the light reflected by the second concave spherical mirror 300 falls on the optical sensor 400, so that the light can be acquired by the optical sensor 400. As long as the second exit focus 320 is located on the optical sensor 400, for example, the optical sensor 400 includes a photosensitive area, the photosensitive area can be used to collect light, and the second exit focus 320 is located on the photosensitive area.

Wherein, the curvature of the second concave spherical mirror 300 is different, and the positions of the second incident focus 310 and the second exit focus 320 may be different. In this application, the placement positions of the sample to be tested 20 and the optical sensor 400 can be determined in advance, and then the second concave spherical mirror 300 with appropriate curvature can be selected. Alternatively, a second concave spherical mirror 300 with a curvature can be selected first, and then the second concave spherical mirror can be adjusted by adjusting the second concave spherical mirror 300 . 300, the sample to be measured 20 and the optical sensor 400 are placed so that the sample to be measured 20 is located at the second incident focus 310 and the optical sensor 400 is located at the second exit focus 320. In this embodiment, the first concave spherical mirror 200 and the second concave spherical mirror 300 are integrated structures. In some embodiments, the first concave spherical mirror 200 and the second concave spherical mirror 300 can be independent structures. The first concave spherical mirror 200 and the second concave spherical mirror 300 can be spherical or ellipsoidal, and the specific curvature can be set according to actual requirements.

The light propagation path in this embodiment is: multiple light rays L with different exit angles are incident from the first incident focus 210 to the first concave spherical mirror 200, are reflected by the first concave spherical mirror 200 to the sample 20 to be measured, and are reflected by the first concave spherical mirror 200. The measured sample 20 reflects to the second concave spherical mirror 300 , is reflected by the second concave spherical mirror 300 , and then enters the optical sensor 400 .

In this embodiment, the device 10 for detecting the surface state of the sample to be tested also includes a processing circuit 500. The processing circuit 500 is electrically connected to the optical sensor 400. The processing circuit 500 is used to determine the polishing end point based on the light acquired by the optical sensor 400. The optical sensor 400 includes but is not limited to PD, APD, CCD or CMOS sensor. The processing circuit 500 includes an amplification circuit, an analog-to-digital conversion circuit, a calculation circuit, etc.

In this embodiment, the sample 20 to be tested is a wafer, which includes multiple dielectric layers and multiple metal layers. When preparing the wafer into a specific product, a chemical mechanical polishing method is used to polish the dielectric layers. Or the metal layer is removed, and the reflection intensity of light incident on the surface of different materials is different, so the grinding end point can be determined based on the change in reflection intensity.

As shown in Figure 3, the wafer 20 includes a dielectric layer 21 and a metal layer 22. Assume that the metal layer 22 needs to be removed through chemical mechanical polishing in this embodiment. During the polishing process, the light L is always incident on the wafer 20. When the metal layer 22 is not completely removed, the light L is incident on the surface of the wafer 20 with the metal layer 22. At this time, the surface of the wafer 20 reflects the reflected light L1 with the reflection intensity A1. When the metal layer 22 is completely removed by grinding After removal (as shown in Figure 4), the dielectric layer 21 will be exposed. Since the material of the surface where the light L is incident has changed, the surface of the wafer 20 reflects the reflected light L2 whose reflection intensity changes to A2. A2 is not equal to A1, and is The light reflected by the wafer 20 is reflected into the optical sensor 400 through the second concave spherical mirror 300. The optical sensor 400 then sends the light with different reflection intensities to the processing circuit 500. The processing circuit 500 can determine the wafer according to the change in the light reflection intensity. Whether the circle reaches the grinding end point. In this application, multiple light rays with different incident angles are incident on the surface of the wafer 20 . When the material of the surface of the wafer 20 changes, multiple light rays with changing reflection intensity will be generated. The changed multiple light rays are incident on the surface of the wafer 20 . The optical sensor 400 is then processed by the processing circuit 500 to obtain the average value of the intensity changes of multiple light rays. The error in determining whether the wafer 20 has reached the polishing end point through the average value is smaller, making the determination result of the polishing end point more accurate.

In the prior art, a plane mirror is used for reflection. There is only one incident angle for the light reflected by the plane mirror to enter the sample 20 to be measured, and there is only one change value of the light reflection intensity, which results in a large error in determining the grinding end point. As shown in Figure 5, the detection device includes a light source 11, a plane mirror 12, a sample to be tested 20 and an optical sensor 13. Since the angle of light reflected by the plane mirror to the sample to be tested 20 is single, the incident angle of the light incident on the sample to be tested 20 is one. , the reflection angle is only one, and the reflection intensity value that reflects the change of the wafer surface material is also only one. There is only one light intensity change value after reflection from the sample 20 to be measured to the optical sensor 13, which makes the detection effect error larger, especially They are two layers with little change in the material properties of the wafer surface. For example, when the wafer 20 includes a first dielectric layer 23 and a second dielectric layer 24, and the material properties of the first dielectric layer 23 and the second dielectric layer 24 are not much different. , when the second dielectric layer 24 is removed by chemical mechanical polishing, the reflection intensity of the light incident on the second dielectric layer 24 and the first dielectric layer 23 does not change much at one of the incident angles, causing errors in the determination of the polishing end point. . When the solution in this application is adopted, multiple light rays with multiple incident angles are incident on the second dielectric layer 24 and have multiple reflected light intensity change values after being incident on the first dielectric layer 23. The average value of the reflected light intensity change values or the maximum intensity change value is used to determine the grinding end point. Compared with the judgment result of one intensity change value, the error can be reduced. Similarly, in some cases, when the polishing end point of the wafer 20 is from one metal layer to another metal layer, and the material properties of the two metal layers are not much different, the application is used to detect the test object. The judgment error of the device 10 for the surface condition of the sample is smaller.

For another example, when there are already some patterned metal traces or dielectric patterns on the surface of the wafer 20, the size of the patterned metal or dielectric is relatively small, and the light will be diffracted on the surface. When the method shown in Figure 5 is used, , if the light at this incident angle is not within its nth order diffracted light range, this light will be diffracted on the surface of the wafer 20 , which is likely to cause errors in detection and judgment. When using the solution of this application, multiple light rays with multiple incident angles are incident on the surface of the wafer 20. When the surface of the wafer 20 has patterned metal traces or dielectric patterns, if the light rays at one of the incident angles are diffracted. , light at other incident angles does not diffract, and non-diffracted light can effectively detect the grinding end point, thereby reducing detection errors.

In addition, if multiple plane mirrors 12 are added to the solution shown in Figure 5 to add multiple light rays with different incident angles, on the one hand, it will increase the cost and increase the occupied space, making the device 10 for detecting the surface state of the sample to be tested The volume becomes larger; on the other hand, the same number of optical sensors needs to be matched. Multiple optical sensors will occupy the area of the circuit board, and will also cause the processing circuit 500 to become more complex. In this application, only one optical sensor 400 is needed, which greatly saves space and simplifies the circuit.

The device 10 provided by this application for detecting the surface state of a sample to be tested uses a light source assembly 100 to emit multiple light rays with different exit angles, and the light rays are incident on the sample 20 to be tested through the first concave spherical mirror 200, so that the light rays are incident on the sample 20 to be tested. The light of the sample to be tested 20 is light with multiple different incident angles. When the surface state of the sample to be tested 20 changes, reflected light with multiple different intensity changes will be generated, which is to say that it is used to detect the surface state of the sample to be tested. The light has multiple incident angles, thereby producing reflected light with multiple intensity changes. The intensity change of the emitted light can reflect the surface state of the sample to be tested, and the comparison is judged by the average of the multiple intensity change values of the multiple light rays. The intensity change value of light at a single incident angle can reduce measurement errors; in this application, these multiple reflected light rays with different intensity changes are incident on the second concave spherical mirror 300, and then are converged and reflected to the optical sensor 400, that is, It is said that only one optical sensor 400 can acquire multiple reflected lights with different intensity changes, which can save space and size and simplify the processing circuit.

Please continue to refer to FIG. 2. In a possible implementation, the light source assembly 100 includes a light source 110 and an emission auxiliary component 120. The emission auxiliary component 120 is used to incident the light emitted by the light source 110 into the first concave surface in a preset angle range. Spherical mirror 200. The light source 110 may be one of a halogen light source, a laser light source, or an LED light source, and the light emitted by the laser light source may be a laser of any wavelength, for example, a laser with a wavelength of 670 nm is generated. The light emitted by the general light source 110 will diverge to the surroundings with the light source 110 as the center. When there is no emission auxiliary member 120, there will also be multiple light beams with different exit angles incident on the first concave spherical mirror 200. In this application, the incident light is incident on the first concave spherical mirror 200. The light reflected from the first concave spherical mirror 200 to the sample 20 to be measured is called the working light. In addition to the working light, light in other angle ranges will interfere with the working light and may affect the judgment accuracy. In this embodiment, the emission auxiliary member 120 allows the light emitted by the light source 110 to gather into a preset angle range. On the one hand, it can enhance the intensity of the light incident on the first concave spherical mirror 200, and on the other hand, it can reduce the influence of other light rays on the working light. interference. The preset angle range can be set according to actual needs.

Please continue to refer to Figure 2. In one possible implementation, the emission auxiliary component 120 is an optical fiber 130, the light source 110 is located at the first end 131 of the optical fiber 130, and the light emitted by the light source 110 is incident on the optical fiber from the first end 131 of the optical fiber 130. In 130, the second end 132 of the optical fiber 130 is the light exit end of the light source assembly 100. The second end 132 of the optical fiber 130 is located at the first incident focus 210 of the first concave spherical mirror 200. The light incident on the optical fiber 130 is emitted from the optical fiber 130. The second end 132 emerges onto the first concave spherical mirror 200 .

The optical fiber 130 is used as the emission auxiliary component 120. The optical fiber 130 has certain bending properties, which makes the placement of the light source 110 more flexible. The length of the optical fiber 130 can be long or short, for example, when placing the device 10 for detecting the surface state of the sample to be tested. When the space size is limited, the light source 110 can be set at a position that can save size according to the actual situation, and then the light is introduced to the light emission position through the optical fiber 130 , that is, the second end 132 of the light 130 only needs to be placed on the first concave spherical mirror 200 The first emission focus is 210.

In addition, when the light source 110 is directly placed at the first emission focus 210 of the first concave spherical mirror 200, the light source 110 is relatively close to the sample to be measured 20 and the optical sensor 400, and the heat generated when emitting light will affect the surface state of the sample to be measured 20 or may cause damage to the surface of the sample 20. Affects the performance of the optical sensor 400 in collecting reflected light, thereby affecting the detection accuracy. In this embodiment, the optical fiber 130 is used to transmit light, and the light source 110 can be set at other positions, thereby reducing the heat generated by the light source 110 when emitting light on the surface of the sample 20 to be measured Or the influence of the optical sensor 400, thereby improving the detection accuracy.

The angular range of the light emitted by the second end 132 of the optical fiber 130 can be determined according to the numerical aperture of the optical fiber 130. Generally, the larger the numerical aperture of the optical fiber 130, the wider the angular range of the emitted light.

Referring to Figure 6, in a possible implementation, the light source assembly 100 further includes a beam expander 140. The beam expander 140 is located between the second end 132 of the optical fiber 130 and the first concave spherical mirror 200. The beam expander 140 is The light emitted from the second end 132 of the optical fiber 130 is diverged to a predetermined angle range. In some cases, the numerical aperture of the optical fiber 130 is small, and the angle range of the light emitted from the optical fiber 130 is narrow, which cannot meet the detection requirements. In this case, the beam expander 140 can be used to spread the light emitted from the optical fiber 130 to a preset angle range. .

Please continue to refer to FIG. 2. In a possible implementation, the light source assembly 100 further includes an optical coupler 150. The optical coupler 150 is located between the light source 110 and the first end 131 of the optical fiber 130 and is used to transmit the light emitted by the light source 110. Light couples into optical fiber 130. The optical coupler 150 may be composed of multiple lenses. Generally, the light emitted by the light source 110 has a wide range, and the light needs to be coupled into the optical fiber 130 through the optical coupler 150 to increase the intensity of the light incident on the optical fiber 130 .

In some embodiments, the light source assembly 100 further includes an optical filter located between the light source 110 and the first end 131 of the optical fiber 130 for filtering the light emitted by the light source 110 so that the light coupled into the optical fiber 130 is light with a specific wavelength. The wavelength of the light used to detect the surface state of the sample to be tested depends on the surface state of the sample to be tested 20 and the characteristics of the optical sensor 400 . That is to say, the surface state of the sample to be tested 20 is different, which can reflect the light at the end of the grinding process. The wavelength range may be different, and different optical sensors 400 have different sensitivities to light in different wavelength ranges, which can be set according to actual needs. Light with specific wavelengths can be obtained through optical filters. When the light source assembly 100 has the optical coupler 150, the optical filter can be disposed between the optical coupler 150 and the light source 110, or the optical filter can be disposed between the optical coupler 150 and the first end 131 of the optical fiber 130. .

Please refer to Figure 7. Different from the embodiment shown in Figure 2, in one possible implementation, the emission auxiliary component 120 is a light emitting component 160, and the light emitting component 160 is located between the light source 110 and the first concave spherical mirror 200. The light-emitting component 160 is provided with a light-emitting hole 161. The light-emitting hole 161 is the light emitting position of the light source assembly 100. The light-emitting hole 161 is located at the first incident focus 210 of the first concave spherical mirror 200. The part of the light-emitting component 160 other than the light emitting hole 161 It can be used to block light from other angles of the light source 110 . In this embodiment, the light emitted by the light source 110 emits part of the light through the light outlet 161 as the working light. The part of the light outlet component 160 except the light outlet 161 can be used to block the light from other angles of the light source 110, thereby preventing other light from affecting the working light. interference. The light-emitting hole 161 is a through-hole 162 that penetrates the light-emitting component 160 (as shown in FIG. 8 ). The shape of the light-emitting hole 161 is not limited to a slit, a circle, a square, a triangle, or a polygon. In another embodiment, the light outlet hole 161 includes a through hole 162 penetrating the light outlet component 160 and a light-transmitting material 163 filled in the through hole 162 (as shown in FIG. 9 ).

In a possible implementation, the light emitting component 160 is one of the light emitting plate 164 or the light emitting cover 165 . The light-emitting component 160 shown in Figures 7 to 9 is a light-emitting plate 164, and the light-emitting component 160 shown in Figure 10 is a light-emitting cover 165. The light-emitting cover 165 is located outside the light source 110 and can effectively block other unnecessary light to avoid Other lights generate more heat, which affects detection accuracy. In some embodiments, the light output mask 165 may only cover a part of the light source 110 , or the shape of the light mask 165 may be spherical or ellipsoidal.

In this embodiment, a beam expander 140 (as shown in FIG. 11 ) may also be provided on the side of the light outlet 161 away from the light source 110 to diffuse the light emitted from the light outlet 161 to a preset angle range.

Referring to FIG. 12 , the difference from the embodiment shown in FIG. 1 is that the first concave spherical mirror 200 and the second concave spherical mirror 300 are independent components, rather than an integrated structure. During assembly, the separately provided first concave spherical mirror 200 and the second concave spherical mirror 300 have higher assembly flexibility and a wider curvature selection range.

It should be noted that the installation positions of each component of the device 10 for detecting the surface state of the sample to be tested in this application can be set according to the application scenario. For example, when applied to chemical mechanical polishing equipment 1, it can be set according to the structural shape and space of chemical mechanical polishing equipment 1, as long as the above-mentioned light propagation path is satisfied to achieve the purpose of detecting the grinding end point, and it can be set additionally in actual products. A support frame or an existing structural component can be used as a supporting position to fix each component of the device 10 for detecting the surface state of the sample to be tested. The installation position of each component of the device 10 for detecting the surface state of the sample to be tested is not limited to this application. The location diagram shown in the application drawing is attached.

Referring to Figure 13 and Figure 2, one embodiment of the present application also provides a method for detecting the surface state of a sample to be tested. The method for detecting the surface state of a sample to be tested includes step S100, step S200, step S300 and step S400. Detailed steps are described below.

Step S100, use the light source assembly 100 to emit multiple light rays with different exit angles.

Step S200: Inject multiple light rays with different exit angles emitted by the light source assembly 100 from the first incident focus 210 position to the first concave spherical mirror 200, where the light emission position of the light source assembly 100 is located at the first incident focus of the first concave spherical mirror 200. At position 210.

Step S300 , use the first concave spherical mirror 200 to reflect light onto the sample 20 to be tested, where the sample 20 to be tested is located at the first exit focus 220 of the first concave spherical mirror 200 . In this embodiment, the sample 20 to be tested is a wafer, which includes multiple dielectric layers and multiple metal layers. When preparing the wafer into a specific product, a chemical mechanical polishing method is used to polish the dielectric layers. Or the metal layer is removed, and the reflection intensity of light incident on the surface of different materials is different, so the grinding end point can be determined based on the change in reflection intensity.

Step S400, the light reflected by the sample 20 to be measured is reflected to the optical sensor 400 through the second concave spherical mirror 300, where the second incident focus 310 of the second concave spherical mirror 300 coincides with the first exit focus 220 of the first concave spherical mirror 200. , the optical sensor 400 is located on the second exit focus 320 of the second concave spherical mirror 300 .

The first incident focus 210 refers to the incident focus where the light rays are incident on the first concave spherical mirror 200 with the same focus, and the first exit focus 220 refers to the focus where the light rays converge after being reflected by the first concave spherical mirror 200. For the first For the concave spherical mirror 200, the first incident focus point 210 and the first exit focus point 220 are adapted to each other. The same first concave spherical mirror 200 has multiple first incident focus points 210 and multiple first exit focus points 220 matching them. Wherein, the sample 20 to be tested is located at the first exit focus 220 means that the focus point of the light after passing through the detection window 31 falls on the surface of the sample 20 to be tested facing the detection window 31, as long as the first exit focus 220 is located at the detection window 31. The area on the surface of sample 20 that needs to be detected is sufficient.

The second incident focus 310 refers to the incident focus where the light rays enter the second concave spherical mirror 300 with the same focus. The second exit focus 320 refers to the focus where the light rays converge after being reflected by the second concave spherical mirror 300. For the second concave spherical mirror In 300, the second incident focus 310 and the second exit focus 320 are adapted to each other. The same second concave spherical mirror 300 has multiple second incident focus 310 and multiple second exit focus 320 matching them. The fact that the optical sensor 400 is located at the second exit focus 320 of the second concave spherical mirror 300 means that the convergence point of the light reflected by the second concave spherical mirror 300 falls on the optical sensor 400, so that the light can be acquired by the optical sensor 400. As long as the second exit focus 320 is located on the optical sensor 400, for example, the optical sensor 400 includes a photosensitive area, the photosensitive area can be used to collect light, and the second exit focus 320 is located on the photosensitive area.

The method for detecting the surface state of a sample to be tested provided by this application uses the light source assembly 100 to emit multiple light rays with different exit angles, and the light is incident on the sample to be tested 20 through the first concave spherical mirror 200, so that the light is incident on the sample to be tested. The light of the sample 20 to be tested is light with multiple different incident angles. When the surface state of the sample to be tested 20 changes, reflected light with multiple different intensity changes will be generated, which means that it is used to detect the surface state of the sample to be tested. Light has multiple incident angles, thereby producing reflected light with multiple intensity changes. The intensity change of the emitted light can reflect the surface state of the sample to be tested. The average of the multiple intensity change values of the multiple light rays is used to determine the relative intensity of the light. The intensity change value of light at a single incident angle can reduce measurement errors; in this application, these multiple reflected light rays with different intensity changes are incident on the second concave spherical mirror 300, and then are converged and reflected to the optical sensor 400, that is to say Only one optical sensor 400 can acquire multiple reflected lights with different intensity changes, which can save space and simplify the processing circuit.

In this embodiment, it is used to detect the grinding end point of the sample 20 to be tested, that is, the grinding end point is determined by judging the material change on the surface of the sample 20 to be tested. In some embodiments, the surface state of the sample 20 to be tested is the surface texture or fine structure of the sample 20 to be tested. The fine structures include protrusions, depressions, scratches, stains, foreign matter, cracks, etc. When light is incident on the surface of the sample 20 to be measured, if the surface texture or surface fine structure is different, the intensity of the light after reflection on the surface will also be different, and thus reflected light intensity information reflecting the surface texture or fine structure can be obtained. When used to detect the surface texture or fine structure of the sample to be tested 20, the method for detecting the surface state of the sample to be tested 20 can also be applied to detect product defects. The first concave spherical mirror 200 is used to detect the light incident on the sample 20 to be tested. For light with multiple different incident angles, when the surface texture or fine structure of the sample 20 to be tested is different from the standard sample, multiple reflected rays with different intensity changes will be generated. Compared with the light with a single incident angle, the reflected light can be reduced. Measurement error.

Please continue to refer to Figure 13 and Figure 2. In a possible implementation, the method for detecting the surface state of the sample to be tested also includes step S500 and step S600. Detailed steps are described below.

In step S500, the optical sensor 400 transmits the received light to the processing circuit 500. The light beams with multiple different reflection intensities emitted from the second concave spherical mirror 300 are received by the optical sensor 400 and then transmitted to the processing circuit 500 . The processing optical sensor 400 includes but is not limited to PD, APD, CCD or CMOS sensor. The processing circuit 500 includes an amplification circuit, an analog-to-digital conversion circuit, a calculation circuit, etc.

In step S600, the processing circuit 500 determines the surface state of the sample 20 to be tested based on the light. In this embodiment, the processing circuit 500 determines the surface material change of the sample to be tested 20 based on the light, and then determines the grinding end point of the sample to be tested 20 .

Referring to Figure 14 and Figure 2, in a possible implementation, step S100 includes step S110 and step S120. Detailed steps are described below.

Step S110, use the light source 110 to emit light.

Step S120 , use the emission auxiliary component 120 to make the light emitted by the light source 110 incident on the first concave spherical mirror 200 in a preset angle range.

The light source 110 may be one of a halogen light source, a laser light source, or an LED light source, and the light emitted by the laser light source may be a laser of any wavelength, for example, a laser with a wavelength of 670 nm is generated. The light emitted by the general light source 110 will diverge to the surroundings with the light source 110 as the center. When there is no emission auxiliary component 120, there will also be light with a certain preset angle range incident on the first concave spherical mirror 200. In this application, the incident light is incident on the first concave spherical mirror 200. The light reflected from the first concave spherical mirror 200 to the sample 20 to be measured is called the working light. In addition to the working light, light in other angle ranges will interfere with the working light and may affect the judgment accuracy. In this embodiment, the emission auxiliary member 120 is used to gather the light emitted by the light source 110 to a preset angle range. On the one hand, the intensity of the light incident on the first concave spherical mirror 200 can be enhanced, and on the other hand, the impact of other light on the working light can be reduced. interference. The preset angle range can be set according to actual needs.

Please continue to refer to Figure 14 and Figure 6. In a possible implementation, step S100 also includes step S130.

Step S130 , use the beam expander 140 to spread the light emitted from the emission auxiliary member 120 to a preset angle range. The beam expander 140 is located between the emission auxiliary member 120 and the first concave spherical mirror 200 . When the light emitted by the emission auxiliary component 120 cannot meet the detection requirements, the beam expander 140 can be used to diffuse the light emitted from the emission auxiliary component 120 to a preset angle range.

In some embodiments, step S100 further includes using an optical filter to filter the light emitted by the light source 110 so that the light coupled into the optical fiber 130 is light with a specific wavelength. The optical filter is located between the light source 110 and the first end 131 of the optical fiber 130 . The wavelength of the light used to detect the surface state of the sample to be tested depends on the surface state of the sample to be tested 20 and the characteristics of the optical sensor 400 . That is to say, the surface state of the sample to be tested 20 is different, which can reflect the light at the end of the grinding process. The wavelength range may be different, and different optical sensors 400 have different sensitivities to light in different wavelength ranges, which can be set according to actual needs. Light with specific wavelengths can be obtained through optical filters.

Please continue to refer to 2. In this embodiment, the emission auxiliary component 120 is an optical fiber 130. Step S120 is to use the optical fiber 130 to incident the light emitted by the light source 110 into the first concave spherical mirror 200 in a preset angle range. Step S130 is to use the beam expander 140 to spread the light emitted from the optical fiber 130 to a preset angle range. The beam expander 140 is located between the optical fiber 130 and the first concave spherical mirror 200 .

The light source 110 is located at the first end 131 of the optical fiber 130. The light emitted by the light source 110 is incident from the first end 131 of the optical fiber 130 into the optical fiber 130. The second end 132 of the optical fiber 130 is the light exit end of the light source assembly 100. The optical fiber 130 The second end 132 is located at the first incident focus 210 of the first concave spherical mirror 200 , and the light incident on the optical fiber 130 is emitted from the second end 132 of the optical fiber 130 to the first concave spherical mirror 200 .

Optical fiber 130 is used as the launch auxiliary component 120. The optical fiber 130 has certain bending properties, which makes the placement of the light source 110 more flexible. The length of the optical fiber 130 can be long or short. For example, when the installation space is limited, the light source 110 can be placed according to the actual situation. It is set at a position that can save size, and then the light is introduced to the light emission position through the optical fiber 130, that is, the second end 132 of the light 130 only needs to be placed on the first emission focus 210 of the first concave spherical mirror 200.

In addition, when the light source 110 is directly placed at the first emission focus 210 of the first concave spherical mirror 200, the light source 110 is relatively close to the sample to be measured 20 and the optical sensor 400, and the heat generated when emitting light will affect the surface state of the sample to be measured 20 or may cause damage to the surface of the sample 20. Affects the performance of the optical sensor 400 in collecting reflected light, thereby affecting the detection accuracy. In this embodiment, the optical fiber 130 is used to transmit light, and the light source 110 can be set at other positions, thereby reducing the heat generated by the light source 110 when emitting light on the surface of the sample 20 to be measured Or the influence of the optical sensor 400, thereby improving the detection accuracy.

The angular range of the light emitted by the second end 132 of the optical fiber 130 can be determined according to the numerical aperture of the optical fiber 130. Generally, the larger the numerical aperture of the optical fiber 130, the wider the angular range of the emitted light.

In some embodiments, step S100 further includes using an optical coupler 150 to couple the light emitted by the light source 110 into the optical fiber 130 . The optical coupler 150 may be composed of multiple lenses. Generally, the light emitted by the light source 110 has a wide range, and the light needs to be coupled into the optical fiber 130 through the optical coupler 150 to increase the intensity of the light incident on the optical fiber 130 .

Please continue to refer to FIG. 7 . In some embodiments, the emission auxiliary component 120 is a light emitting component 160 . Step S120 is to use the light emitting component 160 to incident the light emitted by the light source 110 into the first concave spherical mirror 200 in a preset angle range. Please continue to refer to Figure 11. Step S130 is to use the beam expander 140 to diffuse the light emitted from the light emitting component 160 to a preset angle range. The beam expander 140 is located between the light emitting component 160 and the first concave spherical mirror 200.

Among them, the light-emitting component 160 is provided with a light-emitting hole 161. The light-emitting hole 161 is the light emitting position of the light source assembly 100. The light-emitting hole 161 is located at the first incident focus 210 of the first concave spherical mirror 200. The light-emitting component 160 is other than the light emitting hole 161. The portion can be used to block light from other angles of the light source 110 . In this embodiment, part of the light emitted by the light source 110 passes through the light exit hole 161 as working light. The part of the light exit component 160 except the light exit hole 161 can be used to block light from other angles of the light source 110 to avoid other light rays from affecting the working light. interference. The light-emitting hole 161 is a through-hole 162 that penetrates the light-emitting component 160 (as shown in FIG. 8 ). The shape of the light-emitting hole 161 is not limited to a slit, a circle, a square, a triangle, or a polygon. In another embodiment, the light outlet hole 161 includes a through hole 162 penetrating the light outlet component 160 and a light-transmitting material 163 filled in the through hole 162 (as shown in FIG. 9 ).

In a possible implementation, the light emitting component 160 is one of the light emitting plate 164 or the light emitting cover 165 . The light-emitting component 160 shown in Figures 7 to 9 is a light-emitting plate 164, and the light-emitting component 160 shown in Figure 10 is a light-emitting cover 165. The light-emitting cover 165 is located outside the light source 110 and can effectively block other unnecessary light to avoid Other lights generate more heat, which affects detection accuracy. In some embodiments, the light output mask 165 may only cover a part of the light source 110 , or the shape of the light mask 165 may be spherical or ellipsoidal.

In this embodiment, a beam expander 140 (as shown in FIG. 11 ) may also be provided on the side of the light outlet 161 away from the light source 110 to diffuse the light emitted from the light outlet 161 to a preset angle range.

The above are only specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any person familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application. should be covered by the protection scope of this application. Therefore, the protection scope of this application should be subject to the protection scope of the claims.

Claims (17)

A device for detecting the surface state of a sample to be tested, characterized in that the device for detecting the surface state of a sample to be tested includes: A light source component, the light source component is used to emit multiple light rays with different exit angles; A first concave spherical mirror, the light emission position of the light source assembly is located at the first incident focus position of the first concave spherical mirror, and the sample to be measured is located at the first exit focus of the first concave spherical mirror; a second concave spherical mirror, the second incident focus of the second concave spherical mirror coincides with the first exit focus of the first concave spherical mirror; An optical sensor is located at the second exit focus of the second concave spherical mirror. The device for detecting the surface state of a sample to be tested according to claim 1, characterized in that the light source assembly includes a light source and an emission auxiliary part, and the emission auxiliary part is used to convert the light emitted by the light source to have a predetermined Assume that the angle range is incident on the first concave spherical mirror. The device for detecting the surface state of a sample to be tested according to claim 2, wherein the emission auxiliary component includes an optical fiber, the light source is located at the first end of the optical fiber, and the light emitted by the light source is emitted from the optical fiber. The first end of the optical fiber is incident into the optical fiber, the second end of the optical fiber is the light exit end of the light source assembly, and the second end of the optical fiber is located at the first incident focus position of the first concave spherical mirror. on the optical fiber, the light incident on the optical fiber is emitted from the second end of the optical fiber to the first concave spherical mirror. The device for detecting the surface state of a sample to be tested according to claim 3, wherein the light source assembly further includes a beam expander, the beam expander is located at the second end of the optical fiber and the first end of the optical fiber. Between the concave spherical mirrors, the beam expander is used to spread the light emitted from the second end of the optical fiber to have the preset angle range. The device for detecting the surface state of a sample to be tested according to claim 3, wherein the light source assembly further includes an optical coupler, the optical coupler is located between the light source and the first end of the optical fiber. time for coupling the light emitted by the light source into the optical fiber. The device for detecting the surface state of a sample to be tested according to claim 2, wherein the emission auxiliary component includes a light emitting component located between the light source and the first concave spherical mirror, so The light-emitting component is provided with a light-emitting hole. The light-emitting hole is the light-emitting position of the light source assembly. The light-emitting hole is located at the first incident focus position of the first concave spherical mirror. In addition to the light-emitting component, the light-emitting component The part other than the hole is used to block the light from the light source. The device for detecting the surface state of a sample to be tested according to claim 6, wherein the light outlet hole is a through hole that penetrates the light outlet component. The device for detecting the surface state of a sample to be tested according to claim 6, wherein the light outlet hole includes a through hole that penetrates the light outlet component and a light-transmitting material filled in the through hole. The device for detecting the surface state of a sample to be tested according to any one of claims 1 to 8, characterized in that the first concave spherical mirror and the second concave spherical mirror are integrated structures. The device for detecting the surface state of the sample to be tested according to any one of claims 1 to 9, characterized in that the device for detecting the surface state of the sample to be tested further includes a processing circuit, and the processing circuit is connected to the surface state of the sample to be tested. The optical sensor is electrically connected, and the processing circuit is used to determine the surface state of the sample to be measured based on the light acquired by the optical sensor. A kind of chemical mechanical polishing equipment, characterized in that the chemical mechanical polishing equipment includes a polishing pad and a device for detecting the surface state of the sample to be tested as described in any one of claims 1-10, the device for detecting the surface state of the sample to be tested is The device for measuring the surface condition of the sample is located below the polishing pad, and the polishing pad is used to carry the sample to be measured. The chemical mechanical polishing equipment of claim 11, wherein the polishing pad includes a detection window, the detection window is capable of transmitting light, and the light reflected from the first concave spherical mirror is incident through the detection window. onto the sample to be tested. A method for detecting the surface state of a sample to be tested, characterized in that the method for detecting the surface state of a sample to be tested includes: Use a light source component to emit multiple light rays with different exit angles; The plurality of light rays with different exit angles emitted by the light source assembly are incident on the first concave spherical mirror from a first incident focus position, wherein the light emission position of the light source assembly is located on the first side of the first concave spherical mirror. At the incident focus position; Use the first concave spherical mirror to reflect the light onto the sample to be measured, wherein the sample to be measured is located at the first exit focus of the first concave spherical mirror; The light reflected by the sample to be measured is reflected to the optical sensor through the second concave spherical mirror, wherein the second incident focus of the second concave spherical mirror coincides with the first exit focus of the first concave spherical mirror, and the optical sensor The sensor is located at the second exit focus of the second concave spherical mirror. The method for detecting the surface state of a sample to be tested according to claim 13, wherein the method for detecting the surface state of a sample to be tested further includes: The optical sensor transmits the received light to a processing circuit; The processing circuit determines the surface state of the sample to be tested based on the light. The method for detecting the surface state of a sample to be tested according to claim 13 or 14, characterized in that the use of a light source component to emit multiple light rays with different exit angles includes: using said light source to emit light; The light emitted by the light source is incident on the first concave spherical mirror in a preset angle range using an emission auxiliary component. The method for detecting the surface state of a sample to be tested according to claim 15, wherein the use of a light source component to emit multiple light rays with different exit angles further includes: A beam expander is used to spread the light emitted from the emission auxiliary part to have the preset angle range, and the beam expander is located between the emission auxiliary part and the first concave spherical mirror. The method for detecting the surface state of a sample to be tested according to any one of claims 13 to 16, wherein the sample to be tested is a wafer.

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