WO2000046845A1

WO2000046845A1 - Method for detecting alignment mark in charged particle beam exposure apparatus

Info

Publication number: WO2000046845A1
Application number: PCT/JP2000/000559
Authority: WO
Inventors: Mamoru Nakasuji; Osamu Arai; Tomoharu Fujiwara; Teruaki Okino
Original assignee: Nikon Corporation
Priority date: 1999-02-02
Filing date: 2000-02-02
Publication date: 2000-08-10
Also published as: JP2000223404A; AU2324300A

Abstract

Assuming that the dosage of a charged particle beam (EB) projected in detecting an alignment mark (1) is half the dosage to a sub-field (S) in the process of forming an ordinal pattern, the positive resist having a film thickness of more than 86 % of that before the development is left. As a result, even if etching is done after the development, the alignment mark (1) is not damaged.

Description

Specification

Method for Detecting Alignment Marks in Charged Particle Beam Exposure Apparatus This application is based on Japanese Patent Application No. 255358/1999, the contents of which are incorporated herein by reference. Technical field

The present invention relates to a charged particle beam exposure apparatus and a method for reliably detecting an alignment mark used on an exposure substrate such as a wafer, which is used in the exposure apparatus. Background art

In a charged particle beam exposure apparatus, an image of a pattern formed on a reticle or a mask (hereinafter, referred to as a reticle) is projected and exposed to a light-exposed substrate (simply, a substrate) such as a wafer by a charged particle beam. ing. At this time, a positioning pattern is provided on the reticle, and a positioning mark is provided on the substrate in order to accurately align the relative position between the reticle image and the substrate. Then, the charged particle beam that has passed through the reticle alignment pattern is irradiated onto the alignment mark on the substrate to perform scanning, and secondary electrons and the like generated at that time are detected to perform alignment.

A resist is applied to the entire surface of the substrate on which the alignment mark is formed, and the resist on the alignment mark is also exposed by irradiation of the charged particle beam for alignment. When a positive resist is used as the resist, the resist on the alignment mark is removed when the resist is developed, and the alignment mark is damaged by subsequent etching or the like. Therefore, it was necessary to re-create the alignment mark.

On the other hand, when a negative resist is used, if the amount of exposure at the time of mark detection is insufficient, the resist on the alignment mark is removed when the resist is developed, and The alignment mark will be damaged due to etching and the like. Therefore, in a charged particle beam exposure system of the drawing method, By exposing the area of the alignment mark, the resist is not removed during development to protect the alignment mark. Disclosure of the invention

However, re-creating the alignment mark again has the disadvantages of complicating the whole process and reducing the effective area of the chip due to the need to make room for a new mark. Was. In addition, since the overlay accuracy is lowered due to the mark formation error, the quality is lowered, the manufacturing cost is increased, and it is difficult to manufacture a semiconductor device having a very small line width. Further, in the method of exposing the alignment mark area in the negative resist, there is a problem that the throughput is reduced. In particular, charged particles of a method in which the exposure area is divided into a plurality of stripes and transfer from the reticle to the substrate while continuously moving the reticle and the substrate in the longitudinal direction of each stripe (divided projection transfer method). At present, a line exposure system has not been developed that exposes the alignment mark area without reducing the throughput.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an alignment mark which can prevent a resist on an alignment mark provided on a substrate exposed by a charged particle beam exposure apparatus from being removed by resist development. It is to provide a detection method.

Another object of the present invention is to provide a charged particle beam exposure apparatus capable of reliably detecting a positioning mark without reducing the throughput.

Still another object is to provide a semiconductor device having a small line width and a high degree of integration, and a semiconductor device manufacturing method capable of manufacturing such a semiconductor device.

In order to achieve the above object, a charged particle beam exposure apparatus according to the present invention and a method for detecting an alignment mark used in the exposure apparatus include a method of charging an alignment mark on a substrate coated with a positive type resist. The pattern forming area where the circuit pattern on the substrate is exposed receives the dose of the charged particle beam given to the alignment mark area when scanning with the particle beam and detecting the alignment mark. It was made smaller than the dose. In this way, by making the dose received by the alignment mark area smaller than the dose received by the normal exposure surface in accordance with the positive value of the positive register, the dose on the alignment mark is maintained even after the resist development. The resist can be left. As a result, it is possible to prevent the alignment mark from being damaged by etching or the like due to the remaining resist. Also, since it is not necessary to re-create the alignment mark, the process can be simplified and the overlay accuracy can be improved.

Further, it is preferable that the dose of the charged particle beam given to the alignment mark is less than 1 Z 2 of the dose received by the pattern formation region. In this manner, the resist film thickness after development can be reduced by 15% or less for most types of positive resists.

Further, it is preferable that each of the alignment mark and the charged particle beam scanned on the mark is composed of a plurality of patterns. In this case, the dose received by the alignment mark area is reduced without reducing the detection signal at the time of alignment (for example, reflected electrons or secondary electrons emitted when the alignment mark is irradiated with the charged particle beam). The amount can be reduced.

In the alignment mark detection method according to the present invention, a charged particle beam that projects a pattern from a reticle onto a substrate while continuously moving the reticle and the substrate in the longitudinal direction of each stripe by dividing a pattern formation region on the substrate into a plurality of stripes It relates to a method of scanning a positioning mark on a substrate coated with a negative type resist with a charged particle beam, which is used in an exposure apparatus, to detect a pattern, and a pattern for detecting the positioning mark. Using a reticle in which a mark protection pattern area is formed in proximity to the area where the mark is formed, the above-described detection method includes, before or after the mark detection exposure, the position using a charged particle beam that has passed through the mark protection pattern. The step of exposing the alignment mark is included.

In this case, apart from the mark detection exposure at the time of alignment, the alignment mark is exposed by the charged particle beam that has passed through the mark protection pattern, so that the negative type resist on the alignment mark is not sufficient. Amount of exposure. As a result, the resist remains on the alignment mark even after development, and the Mark damage can be prevented.

Exposure of the alignment mark with the charged particle beam that has passed through the mark protection pattern is performed when the constant speed of the sample stage and reticle stage is not ensured enough to perform pattern exposure and mark detection. Is preferred. In this case, it is possible to perform exposure using the charged particle beam that has passed through the mark protection pattern without lowering the throughput of the entire exposure process.

Further, by using the charged particle beam exposure apparatus and the alignment mark detection method as described above in the lithographic process in the semiconductor device manufacturing method, a semiconductor device having a small line width and a high degree of integration can be manufactured. . BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a flowchart showing a semiconductor device manufacturing method.

FIG. 2 is a flowchart showing the contents of the lithographic process in the wafer processing step.

FIG. 3 is a block diagram showing a schematic configuration of the divided projection exposure apparatus.

FIG. 4 is a diagram showing the relationship between the exposure dose and the residual resist film thickness when a positive resist is used.

FIG. 5 is a diagram for explaining an exposure method in which the dose amount is reduced, and the alignment mask is

FIG. 2 is a diagram showing a laser beam and an electron beam irradiated on the laser beam.

FIG. 6 is a view showing a unit of divisional exposure in an exposure apparatus of a divisional projection transfer system.

FIG. 7 is a diagram showing an exposure method in the divided projection exposure apparatus.

FIG. 8 is a diagram showing an example of a reticle used in a divided projection exposure apparatus. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, a method for manufacturing a semiconductor device to which a charged particle beam exposure apparatus using the method for detecting a positioning mark according to the present invention is applied will be described. FIG. 1 is a flowchart showing a semiconductor device manufacturing method. The main process is a wafer-one manufacturing process for manufacturing a wafer. S1, Wafer processing step for processing necessary to form chips on a wafer S2, Chip assembly step for cutting out chips formed on a wafer one by one and assembling them into a form that can be operated as a device S3, a chip inspection step S4 for inspecting a completed chip, and a mask production step S5 for producing a mask used in the wafer processing step S2.

Among these steps, the step that has a decisive effect on the performance of the semiconductor device is the wafer processing step S2. In the wafer processing step S2, designed circuit patterns are sequentially formed on the wafer, and a large number of device chips that operate as memories and MPUs are formed on the wafer. Therefore, the wafer processing step S2 includes: (1) a thin film forming step of forming a dielectric thin film as an insulating layer using CVD, sputtering, or the like, and a metal thin film for forming wiring portions and electrodes, and (2) a wafer substrate. Lithography, which uses a mask (also called a reticle) to selectively process the thin film layer and wafer-to-substrate, etc. (A) Etching process to process thin film layer and substrate by dry etching using resist pattern, (2) ion implantation process, (4) resist stripping process, (4) cleaning process to clean wafer, and (5) processing It includes an inspection process for inspecting a wafer that has been damaged. Note that the wafer processing step S2 is repeatedly performed for the required number of layers.

FIG. 2 is a flowchart showing the contents of the lithographic process that forms the core of the wafer processing step S2. After applying the resist on the wafer in the resist coating step S11, the resist is exposed by an exposure apparatus using the mask produced in the mask manufacturing step in an exposure step S12. When the exposed resist is developed in the developing step S13, a resist pattern is obtained. This resist pattern is stabilized by the subsequent annealing step S14.

By using an exposure apparatus to which the method of detecting a mark for alignment according to the present invention is applied in the above-described exposure step S12, the throughput, cost, accuracy, and quality of the lithography can be significantly improved. . In particular, the steps involved in achieving the required minimum line width and the corresponding overlay accuracy are lithographic. The exposure process S 12 including the alignment control is important among them. By applying the present invention to this exposure step S12, it becomes possible to manufacture a semiconductor device which has been considered impossible to manufacture.

Next, a schematic configuration of the charged particle beam exposure apparatus will be described with reference to FIG. The electron beam EB emitted from the electron gun 21 is formed into a parallel beam by the condenser lens 22. Reference numeral 23 denotes a beam blank force, which acts as a shirt for turning on / off the electron beam EB emitted from the electron gun 21 to the condenser lens 22 based on the signal of the control amplifier 23a. The electron beam EB that has passed through the condenser lens 22 is deflected by the sub-field selecting deflector 24 and guided to one of the subfields of the reticle 100.

The reticle 100 is mounted on a reticle stage 25, and the reticle stage 25 is horizontally driven in the X-axis and y-axis directions by a driving device 26. The electron beam EB that has passed through the reticle 100 is deflected by a predetermined amount in the X-axis direction and the y-axis direction by the deflector 27, and then the wafer W mounted on the wafer stage 30 by the projection optical system 28. Is projected on a predetermined area of the image. The wafer stage 30 is horizontally driven by the driving device 31 in the X-axis direction and the y-axis direction.

The positions of the reticle stage 25 and the wafer stage 30 in the X-axis direction and the y-axis direction are detected by position detectors 32, 33, such as laser interferometers, respectively, and the detection results are output to the controller 34. You. Data such as exposure conditions are input to the controller 34 in advance, and based on the data and the stage position information from the position detectors 12 and 13, the electronic devices by the deflectors 24 and 27 are used. In addition to calculating the deflection amount of the line EB, information (eg, position and moving speed) necessary for controlling the operations of the reticle stage 25 and the wafer stage 30 is calculated.

The calculation result of the deflection amount is output to the deflection amount setting units 35 and 36, and the deflection amounts of the deflectors 24 and 27 are set by the deflector setting units 35 and 36, respectively. In addition, on / off control of the electron beam EB by the blanking force 23 is also performed based on a command from the control device 34. The operation results of the operations of the reticle stage 25 and the wafer stage 30 are output to drivers 38 and 39, respectively, and the operations of the driving devices 26 and 31 are controlled by the drivers 38 and 39, respectively. . When aligning the reticle 100 with the wafer W, the electron beam EB that has passed through the alignment pattern provided on the reticle 100 is irradiated onto the alignment mark provided on the wafer. Then, secondary electrons and the like generated at that time are detected by the secondary electron detector 40. The detection signal of the secondary electron detector 40 is output to the control device 34, and the control device 34 drives the deflector 27 based on the detection signal, adjusts the beam position, and outputs the reticle 100 Align the image with the wafer W.

As described above, when the circuit pattern is exposed, developed and etched, the resist on the alignment mark needs to remain to some extent. In the present invention, the resist is left by controlling the exposure amount of the resist on the alignment mark. Therefore, the relationship between the exposure dose and the remaining resist film thickness will be described first.

Figure 4 shows the relationship between the electron beam exposure dose (CZ cm ² ) and the remaining resist film thickness when a positive resist is used, with the type of resist as a parameter. The horizontal axis indicates the exposure dose (common logarithmic value), and the vertical axis indicates the relative value of the film thickness of the remaining resist to the film thickness before development. A to c in the figure correspond to the type of the registry. If the dose of the resists a and b is 6 iC / cm 2 or more at the time of exposure, the resist is completely removed by development, and normal pattern formation can be performed. On the other hand, when the dose is 3 (CZ cm ² ) or less, 86% or more of the resist a and 90% or more of the resist b remain after development.

Therefore, if the dose of the electron beam at the time of detecting the alignment mark is set to 1/2 of the dose used for normal pattern formation, 86% or more of the original film thickness remains. become. The same is true for the resist c, although the numerical values are different, and are common to most resists. Therefore, by setting the dose of the charged particle beam to be applied when detecting the alignment mark to 12 which is the dose used for normal pattern formation, the resist on the alignment mark can be maintained even after development. Still remain, and the alignment mark is not damaged by etching or the like. The method of decreasing the dose may be set so as to be optimal according to the γ value of the resist to be used and the number of exposures of the wafer until completion. An example of an exposure method in which such a dose is reduced will be described with reference to FIG. In FIG. 5, reference numeral 1 denotes an alignment mark formed on the wafer W. In the example shown in FIG. 5, three marks are formed. The width is A, and the pitch between the marks 1 is B. Reference numeral 2 denotes an electron beam EB projected on the wafer W through a positioning pattern (not shown) provided on the reticle 100, and is an image of the positioning pattern. Three alignment patterns are also provided. The width of the image 2 projected on the wafer W is C, and the pitch is B, which is the same as the pitch of the alignment mark 1. The electron beam EB forming the image 2 is deflected by the deflector 27 in FIG. 3, and the image 2 is scanned at a constant speed in the direction in which the marks 1 are arranged (the left-right direction in the figure). If the scanning time at this time is T, the scanning speed is BZT.

Secondary electrons emitted when each alignment mark 1 is irradiated with the electron beam EB are detected by the secondary electron detector 40, and when the number of secondary electrons becomes the largest, each image is It is determined that 2 coincides with each alignment mark 1, and based on this signal, the image of reticle 100 and the wafer 1W are aligned.

The exposure time of the normal pattern area (the area where the circuit pattern is exposed) is T ', and the intensity per unit area of the electron beam EB that irradiates the reticle 100 during alignment is the normal pattern area. Assuming that this is the same as during exposure, the dose received by the resist on the alignment mark 1 during alignment is CT / {(B + C) T '} of the dose received by the normal pattern portion. Double. If this value is set to 1 or less by appropriately selecting C and T, the dose received by the resist on the alignment mark 1 can be set to an arbitrary value smaller than the dose received by the normal pattern portion. . Usually, the scanning time T is set equal to the exposure time T '.

In FIG. 5, the number of the alignment marks 1 on the wafer W and the number of the alignment patterns (the number of images 2) on the reticle 100 are plural, because the alignment marks 1 This is because even if the dose of the electron beam EB is reduced, the amount of secondary electrons required for alignment is generated. In the example shown in FIG. 5, the number of the alignment marks 1 and the number of the images 2 are each three.If these numbers are increased, the dose of the electron beam EB received by the alignment mark area can be increased. And can generate many secondary electrons. Next, protection of the alignment mark when a negative resist is used will be described. FIG. 6 is a view for explaining the exposure method of the divided projection transfer system, and is a view showing a unit of the divided exposure. First, a plurality of chips 3 are formed on a substrate (usually a wafer) W, and the area of the chip 3 is divided into a plurality of stripes 4 and each stripe 4 is divided into a plurality of subfields S. I have. On reticle 100, a pattern to be transferred to the area of chip 3 is formed. This pattern is divided into stripes 10 (see FIG. 7) corresponding to stripes 4 of chip 3, and further divided into stripes 1 and 2. 0 is divided into subfields S 'corresponding to the subfield S of stripe 4.

In a divided projection exposure apparatus, exposure is usually performed by a method as shown in FIG. In FIG. 7, one stripe 4 of one wafer W and a stripe 10 corresponding to the stripe 4 are shown. First, the reticle stage 25 and the wafer stage 30 are moved at a constant speed along the center of the stripes 4 and 10 at a speed ratio close to the reduction ratio. The subfield S 'on the reticle 100 is illuminated by the electron beam EB, and an image of the pattern formed in the subfield S' is projected by the projection optical system 28 (see FIG. 3) onto the corresponding subfield S of the wafer W. It is reduced and projected on top.

Then, the electron beam EB is deflected in a direction substantially perpendicular to the traveling direction of the reticle stage 30, and the subfields S 'and S arranged in a row are sequentially subjected to projection exposure. When the projection exposure of one row of subfields S ′ and S is completed, the projection exposure of the next row of subfields SS is started. At this time, as shown in FIG. The throughput is increased by sequentially projecting and exposing subfields S ′ and S like lines L ′ and L.

Compared with a conventional charged particle beam exposure apparatus, a divided projection exposure apparatus that performs exposure in this manner shows that the subfield area is exposed all at once, and that the reticle 100 has all the patterns to be exposed. Therefore, the throughput can be greatly improved.

The reticle 100 used in this exposure method is divided into a subfield S 'where a pattern is formed and a beam ST around it, as shown in Fig. 7, unlike the case of an exposure apparatus using light. I have. The beam ST increases the strength of the reticle 100 itself. It is provided to keep it.

FIG. 8 is a view showing a part of a reticle 100 used in a split projection type electron beam exposure apparatus. A negative type resist is used as a resist applied to one wafer W. In FIG. 8, a plurality of stripes 10 are formed in the X-axis direction, and 11 is a beam portion formed between adjacent stripes 10. Numeral 1 2 indicates a general sub-field (corresponding to sub-field S ′ in FIGS. 6 and 7) on which a transfer pattern is formed. Numeral 13 indicates a sub-field for forming an X-direction alignment beam. Is a sub-field for producing a beam for directional alignment, and 15 is a sub-field for producing a beam for protecting marks. A sub-field 13 has an X-axis direction alignment pattern 16 formed therein, and a sub-field 14 has a y-axis direction alignment pattern formed therein. Patterns 16 and 17 are patterns for forming image 2 shown in FIG. 5 on one wafer W.

The reticle shown in FIG. 8 moves in the longitudinal direction of the stripe 10, that is, in the y direction. At each end of the stripe 10 in the y direction, a subfield 15 for forming a beam for protecting a mark is provided as shown in the figure. Then, a subfield 1 for forming a beam for aligning in the X direction is provided inside the subfield 15. 3 and subfields 14 for producing a beam for alignment in the y direction are provided alternately in the X direction. On the other hand, with regard to wafer W, subfields corresponding to subfields 13 and 14 of reticle 100 are formed at positions corresponding to subfields S on which circuit patterns are projected. In FIG. 8, the subfields 13, 14, and 15 are provided on both sides of the stripe 10, but may be provided only on the side on which the stripe 10 is first exposed.

The alignment between the reticle 100 and the wafer 1 W at the time of exposure is performed every time exposure is performed on one stripe 10. For example, when performing exposure using the reticle shown in FIG. 8, before starting exposure of subfield 12 of stripe 10, alignment is performed using subfields 13 and 14 on the upper side of the figure. After the exposure of the stripe 10 is completed, the positioning is performed using the subfields 13 and 14 on the lower side of the figure. As described above, the subfields 13 and 1 for alignment are located only on the side on which the stripe 10 is first exposed (upper side in the figure). If 4 is provided, alignment is performed before exposure of subfield 12 of stripe 10 starts.

Next, mark protection when a negative resist is used will be described. First, the electron beam EB from the illumination optical system (condenser-lens 23 in FIG. 3) is deflected by a deflector 24 and irradiated to one of the subfields 15. A hole pattern as shown in FIG. 8 is formed in the subfield 15. The electron beam EB that has passed through the hole pattern is placed in the corresponding subfield (on the wafer W provided with the alignment mark). (The subfields corresponding to subfields 13 and 14). At this time, since the y-direction position of the alignment subfield of the wafer W corresponds to the y-direction position of the subfields 13 and 14 of the reticle 100, the reticle 100 is irradiated. The beam of the hole pattern is further deflected by one deflector in the y direction by the deflector 27, and the image of the hole pattern of the subfield 15 is displayed over the entire area where the alignment mark on the wafer W side is formed. To be transcribed. By performing such exposure successively on the subfields 15 arranged in the X direction in FIG. 8, protective exposure is performed on all the positioning subfields. As a result, the alignment subfield of the wafer W is sufficiently exposed in advance. This exposure is omitted when a positive resist is used.

Subsequently, the electron beam EB from the illumination optical system is deflected in the X direction by the deflector 24 to form a subfield 13 for forming a beam for X direction alignment and a subfield 14 for forming a beam for y direction alignment. Irradiation is performed one after another, and the electron beam EB patterned by the pattern of each subfield 13 and 14 is sequentially radiated to the subfield provided with the alignment mark on the wafer 1W side. By deflecting the alignment beam irradiated from the reticle 100 onto the wafer 1W by the deflector 27, each alignment beam is scanned on the wafer 1W, but in the X-axis direction. Scanning is performed in the X-axis direction when detecting alignment marks, and scanning in the y-axis direction when detecting alignment marks in the y-axis direction.

When the patterned electron beam EB (alignment beam) passing through subfields 13 and 14 irradiates the alignment mark of 1 W of the wafer, the alignment is performed. Since secondary electrons are emitted from the markings, the secondary electrons are detected by the detector 40 (see FIG. 3) to detect the relative positional relationship between the reticle 100 and the wafer W. Then, the image of the reticle 100 and the wafer 1 W are aligned based on the detected relative positional relationship, and thereafter, the normal exposure of the subfield 12 is performed. According to the above-described detection method, the subfields 13 and 14 provided with the alignment marks of the wafer W are subjected to sufficient exposure in advance by the electron beam that has passed through the hole formed in the subfield 15. Therefore, even after the resist development, the negative resists on the subfields 13 and 14 remain, and the positioning marks thereunder are not damaged by etching or the like.

As described above, in order to irradiate the protection beam formed in subfield 15 to the subfield provided with the alignment mark of wafer W, in addition to the normal y-axis deflection, one subfield ( The y-axis deflection (for example, about 250 m) must be added to the protection beam. However, if the hole pattern image is made sufficiently larger than the mark area, this mark protection exposure is particularly problematic even if the position is shifted by several am. There is no need to worry about aberrations. By the way, in the division projection type exposure apparatus as described above, when the exposure of one stripe 4, 10 is completed while moving the stages 25, 30 at a constant speed, the moving direction of the stages 25, 30 is Then, exposure of the next stripes 4 and 10 is performed. Therefore, since there is no problem even if the exposure position of the protection beam is slightly shifted, the protection exposure performed every time the stripes 4 and 10 are exposed is performed by exposing the stripes 4 and 10 (exposure transfer of the circuit pattern). Performing this when the constant speed of the stage is not guaranteed, such as during stage acceleration / deceleration before and after the exposure, enables the protection exposure to be performed without lowering the throughput.

As shown in FIG. 8, the X-axis direction alignment pattern 16 and the y-axis direction alignment pattern 17 are thermally affected by electron beam irradiation when the length of each pattern is too long. Since it becomes unstable, it is good to arrange a lot of 10 to 50 / xm. Industrial applicability In the above-described embodiment, an exposure apparatus using an electron beam has been described as an example. However, the present invention is applicable to an exposure apparatus using a charged particle beam including an ion beam.

Claims

Claims A method for detecting a positioning mark in a charged particle beam exposure apparatus, wherein the positioning mark on the substrate coated with the positive type resist is scanned and detected by a charged particle beam,

The dose of the charged particle beam given to the alignment mark area when detecting the alignment mark is made smaller than the dose received by the pattern formation area on the substrate.

2.

In the method for detecting an alignment mark according to claim 1,

The dose of the charged particle beam given to the alignment mark area when detecting the alignment mark is set to be less than 12 of the dose received by the pattern formation area.

3.

The alignment mark detection method according to claim 1, wherein the alignment mark, and the charged particle beam scanned on the alignment mark, have a pattern width and a pattern pitch, respectively. It consists of multiple patterns adjusted to satisfy the dose condition.

Four .

The pattern formation region on the substrate is divided into a plurality of stripes, and the reticle and the substrate are transferred while continuously moving the reticle and the substrate in the longitudinal direction of each stripe. A method for detecting an alignment mark in a charged particle beam exposure apparatus, wherein the alignment mark on a substrate is scanned and detected by a charged particle beam,

Using a reticle in which a mark protection pattern area is formed in proximity to an area in which a pattern for detecting the alignment mark is formed, the detection method includes: before or after mark detection exposure, the mark protection Exposing the alignment mark with a charged particle beam having passed through the alignment pattern.

Five . A method for detecting a positioning mark in a charged particle beam exposure apparatus according to claim 4,

The step of exposing the alignment mark is performed when the constant speed of the sample stage on which the substrate is mounted and the reticle stage on which the reticle is mounted are not guaranteed.

6.

A charged particle beam is irradiated on the reticle on which the pattern is formed, and an image of the pattern is projected onto a pattern formation region of the substrate coated with the positive resist, and the charged particle beam that has passed through the reticle alignment pattern A charged particle beam exposure apparatus that irradiates the alignment mark provided on the substrate with the alignment mark to align the reticle with the substrate.

A reticle stage on which the reticle is mounted,

A sample stage on which the substrate is mounted,

A deflector for deflecting a charged particle beam that passes through the reticle and is irradiated onto the substrate;

A detector for detecting a signal generated when the alignment mark is irradiated with a charged particle beam;

A first control device that controls positions of the reticle stage and the sample stage based on a detection signal of the detector so that a relative position between the reticle and the substrate is a predetermined position;

The charged particle beam that has passed through the alignment pattern is deflected to scan over the alignment mark, and the dose of the charged particle beam given to the alignment mark area is reduced by the pattern formation. A second control device for controlling the deflector so that the dose received by the region is smaller than the dose.

7.

In the charged particle beam exposure apparatus according to claim 6,

The second control device controls the deflector so that the dose of the charged particle beam given to the alignment mark is less than 1 to 2 of the dose received by the pattern formation region.

8.

In the charged particle beam exposure apparatus according to claim 6 or claim 7,

The alignment mark and the charged particle beam scanned on the alignment mark each include a plurality of patterns whose pattern width and pattern pitch are adjusted to satisfy the dose condition.

9.

The pattern formation region on the substrate on which the negative resist is applied is divided into a plurality of stripes, and while the reticle and the substrate are continuously moved in the longitudinal direction of each stripe, projection from the reticle onto the substrate is performed. A charged particle beam exposure apparatus that irradiates a charged particle beam that has passed through the alignment pattern of the reticle onto an alignment mark provided on the substrate to perform alignment between the reticle and the substrate,

A reticle stage on which the reticle is mounted,

A sample stage on which the substrate is mounted,

The charged particle beam that has passed through the alignment pattern is scanned on the alignment mark, and the charged particle beam that has passed through a mark protection pattern provided in close proximity to the alignment pattern is the alignment mark. A second controller for controlling the deflection of the charged particle beam by the deflector so as to irradiate the mark.

Ten .

In the charged particle beam exposure apparatus according to claim 9,

The third controller is configured to control the charged particle beam passing through the mark protection pattern. The irradiation to the alignment mark is controlled to be performed when the constant speed of the sample stage and the reticle stage is not guaranteed.

1 1.

A method for manufacturing a semiconductor device having a lithography step,

The mark detection method according to any one of claims 1 to 5 or the charged particle beam exposure apparatus according to any one of claims 6 to 10 is used in the lithography step.

1 2.

A semiconductor device manufactured by the method for manufacturing a semiconductor device according to claim 11.