WO2024157579A1

WO2024157579A1 - Light heating device

Info

Publication number: WO2024157579A1
Application number: PCT/JP2023/040863
Authority: WO
Inventors: 崇寛東間; 修平三輪田; 貴文溝尻
Original assignee: ウシオ電機株式会社
Priority date: 2023-01-27
Filing date: 2023-11-14
Publication date: 2024-08-02
Also published as: JP2024106437A

Abstract

Provided is a light heating device that increases the efficiency of utilization of light emitted from a heating light source.　The present invention comprises: a chamber which accommodates a heating target; a light source unit which emits heating light toward the heating target and which is disposed outside of the chamber; and a light transmitting part which is for allowing heating light that has been emitted from the light source unit to enter the inside of the chamber. The light source unit is provided with a heating light source that emits the heating light, a reflection member that reflects, toward the heating target, some of the heating light which is emitted from the heating light source and which progresses in in a direction differing from that of the heating target, and a condensing optical system that decreases the angle of divergence, with respect to the direction in which the heating light source and chamber face each other, of the heating light that has been emitted from the heating light source and toward the heating target.

Description

Light heating device

The present invention relates to a light heating device.

In the semiconductor manufacturing process, various heat treatments are performed on semiconductor wafers, such as film formation, oxidation and diffusion, modification, and annealing. These processes often use a heat treatment method that uses light irradiation, which allows for non-contact processing.

As an apparatus for heat-treating a heating object such as a semiconductor wafer, there is known an apparatus equipped with a heating lamp such as a halogen lamp and irradiating the heating object with heating light (hereinafter sometimes referred to as "heating light"). For example, the following Patent Document 1 describes an optical heating apparatus equipped with multiple straight tube-shaped heating lamps.

JP 2017-017277 A

　In order to increase the efficiency of light utilization, conventional optical heating devices equipped with a heat lamp often have a reflecting member that reflects the heating light emitted from the heat lamp and traveling in the direction opposite the object to be heated, toward the object to be heated, as described in the above-mentioned Patent Document 1.

However, the heating light emitted from the heating lamp that is not reflected by the reflective member has low directionality, so a relatively large amount of the light is absorbed by the inner wall surface of the chamber or travels to the outer area of the object to be heated. This type of light does not contribute to heating the object to be heated, and is therefore a factor in reducing the efficiency of light utilization.

Even if a solid-state light source such as an LED or LD is used as the heating light source, the light emitted from the solid-state light source is emitted at a constant divergence angle, so the same problems as with a heating lamp can occur.

In addition, one possible method for not wasting the light that travels outside the object to be heated is to additionally place a reflective member that reflects the light that is emitted from the heating light source toward the object to be heated and travels outside the object so that it is irradiated onto the object to be heated.

However, adding additional reflective members may result in an increase in the size of the entire device. Also, depending on the configuration of the chamber in which the object to be heated is housed, there is a risk that the heating light may be partially blocked, making it impossible to place the reflective members described above in the desired position.

In view of the above problems, the present invention aims to provide an optical heating device that improves the efficiency of using the light emitted from a heating light source.

The light heating device of the present invention is
A light heating device that irradiates a heating object with heating light,
A chamber in which the object to be heated is accommodated;
a light source unit disposed outside the chamber and configured to emit the heating light toward the object to be heated;
a light transmitting portion for introducing the heating light emitted from the light source unit into the inside of the chamber,
The light source unit includes:
A heating light source that emits the heating light;
a reflecting member that reflects a portion of the heating light emitted from the heating light source and traveling in a direction different from the object to be heated, toward the object to be heated;
The heating light source is characterized by comprising a focusing optical system that reduces the divergence angle of the heating light emitted from the heating light source toward the object to be heated in the direction in which the heating light source and the chamber face each other.

In this specification, "reducing the divergence angle" is a concept that includes not only the case of converging incident light toward a single focal position, but also the case of changing the divergence angle in the direction of light travel in a direction that reduces it. It also includes the case of reducing the divergence angle so as to converge light toward a focal line formed in a line by the locus of the focal point, as in the case of a cylindrical lens, and the case of changing the divergence angle of light in the same direction in a direction that reduces it. Note that in this specification, "converging" is a broad concept that includes not only the gathering of light at a focal point, but also the case of simply changing the divergence angle in the direction of light travel in a direction that reduces it. And "converging optical system" refers to an optical system such as a lens that not only gathers light at a focal point as described above, but also changes the divergence angle in the direction of light travel in a direction that reduces it.

The divergence angle of a portion of the light emitted from the heating light source and traveling in a direction different from the reflecting member in the direction in which the heating light source faces the chamber is reduced by the focusing optical system. In other words, in the optical heating device with the above configuration, the heating light emitted from the heating light source is less likely to travel outside the object to be heated, compared to a conventional optical heating device with no focusing optical system. In other words, even when the same power is supplied to the heating light source, more heating light is irradiated to the object to be heated.

Incidentally, optical heating devices that heat-treat objects generally come in a variety of configurations depending on the type of object, the heating method, and the process to be performed. Some optical heating devices are designed to ensure a distance of several centimeters to several tens of centimeters between the heating light source and the object to be heated.

In the optical heating device with the above configuration, the above-mentioned effect becomes more pronounced as the distance between the heating light source and the object to be heated increases. This is because the heating light emitted from the heating light source at a predetermined divergence angle gradually diverges as it travels toward the object to be heated, and details will be described later in the section "Form for implementing the invention" with reference to Figure 8.

Incidentally, even if the distance between the object to be heated and the heating light source is as close as possible, some light still travels outside the object to be heated, so the optical heating device configured as above has the effect of improving the efficiency of light utilization.

In the above-mentioned light heating device,
The heat light source may be a heat lamp including a long arc tube and a pair of electrodes provided at both ends in the extending direction of the arc tube.

The term "long arc tube" as used here is intended to include not only those that extend in a straight line (hereinafter sometimes referred to as "straight tube shape"), but also those that extend in a curved line.

The optical heating device configured as above can use the most suitable heating lamp as the heating light source depending on the size and shape of the object to be heated, improving the efficiency of light utilization and enabling more precise control of the illuminance distribution and temperature distribution on the irradiated surface of the object to be heated.

The light heating device is
The light collecting optical system and the light emitting tube may be integrally constructed.

Here, "the focusing optical system and the light-emitting tube are integrally configured" includes cases where the focusing optical system and the light-emitting tube are joined or bonded together, and cases where the wall of the light-emitting tube is molded to function as a lens.

In the above-mentioned light heating device,
The heating light source may be a halogen lamp.

In addition, in the above-mentioned light heating device,
The heating light source may be a flash lamp.

In the above-mentioned light heating device,
The light emitting tube of the heating light source may be configured to have a straight tube shape.

In addition, in the above-mentioned light heating device,
The heating light source may be configured such that at least a portion of the light emitting tube extends along an arc shape.

Furthermore, the light heating device
The focusing optical system may have a shape extending along an arc, and the heating light source and the focusing optical system may be configured such that, when viewed from the chamber, a first circle along the tube axis of the arc-extending portion of the light-emitting tube of the heating light source and a second circle along the locus of the focal position of the focusing optical system are concentric.

In this specification, the term "concentric" is used to include not only cases where the centers are perfectly aligned, but also cases where the centers are offset to an extent that is unavoidable during manufacturing. Specifically, it is acceptable for the amount of offset in the center position to be within 2% of the radius for each heating light source that extends along an arc.

Compared to a light heating device configured only with straight-tube heating lamps, the light heating device configured as described above can irradiate the main surface of a plate-shaped, particularly a disk-shaped, object to be heated with more uniform light in the circumferential direction.

Furthermore, the light heating device
The second circle may be configured to have a smaller radius than the first circle when viewed from the chamber.

When a focusing optical system is installed to reduce the divergence angle of light emitted from a light source, it is common to align the direction in which light is to be emitted as viewed from the light source with the optical axis of the focusing optical system. In other words, in the above configuration, it is common to align the first circle with the second circle as viewed from the chamber.

However, the inventors have discovered that the above configuration can increase the light utilization efficiency and make the illuminance distribution of the heating light on the irradiated surface of the object to be heated more homogenous. Details of how such effects can be achieved are described in detail in the section "Form for carrying out the invention," along with details of the verification experiment.

In the above-mentioned light heating device,
The reflective member may extend along the tube axis of the light-emitting tube and have a reflective surface whose cross-sectional shape when cut along a plane perpendicular to the direction in which the reflective member extends is parabolic, elliptical, or circular.

In the optical heating device configured as described above, the light emitted from the heating light source and reflected by the reflecting member is reflected so as to be focused toward the object to be heated, compared to the case where a reflecting member with a reflective surface formed on a flat surface is used. Therefore, the utilization efficiency of the light emitted from the heating light source is further improved.

In the above-mentioned light heating device,
The heat light source may be a single-ended heat lamp.

Furthermore, in the light heating device,
The reflecting member may have a reflecting surface along a paraboloid of revolution, an ellipsoid of revolution, or a sphere.

In the above-mentioned light heating device,
The heating light source may include a plurality of solid-state light sources.

Furthermore, in the light heating device,
The light collecting optical system may be provided corresponding to each of the plurality of solid-state light sources.

Compared to heat lamps such as halogen lamps and flash lamps, solid-state light sources require less space for placement. This allows the optical heating device configured as described above to be even more compact overall. In addition, solid-state light sources have a longer lifespan than these heat lamps. This allows the optical heating device configured as described above to require less frequent maintenance.

The present invention provides a light heating device that improves the efficiency of using the light emitted from the heating light source.

2 is a schematic cross-sectional view of an embodiment of a light heating device when viewed in the Y direction. FIG. 2 is an enlarged view of a portion of the light source unit of FIG. 1 . 2 is a diagram of the light source unit of FIG. 1 as viewed from the −Z side. This is a drawing of the circle heater as seen from the +Z side. This is a drawing of the circle heater as seen from the +Y side. FIG. 2 is a perspective view showing a schematic shape of a light collecting optical system. 2 is a schematic cross-sectional view of an embodiment of a light irradiation device when viewed in the Y direction. FIG. FIG. 11 is a schematic cross-sectional view of a conventional light irradiation device as viewed in the Y direction. 13 is a graph showing illuminance distribution in the X direction in an example and a comparative example. 4 is a diagram illustrating a schematic positional relationship between a light source unit and an object to be heated. 1 is a diagram showing an example of the configuration of a light collecting optical system; 1 is a diagram showing an example of the configuration of a light collecting optical system; 2 is an enlarged view of a portion of a light source unit in one embodiment of a light heating device. 1 is a diagram showing a light source unit in an embodiment of a light heating device as viewed from the -Z side. 11 is a schematic cross-sectional view of another embodiment of the light heating device when viewed in the Y direction. FIG. 13 is a diagram of the light source unit in FIG. 12 as viewed from the −Z side. 13 is a schematic enlarged cross-sectional view of a light source unit in another embodiment of the light heating device as viewed in the Y direction. FIG. 13 is a schematic enlarged cross-sectional view of a light source unit in another embodiment of the light heating device as viewed in the Y direction. FIG. 16 is a diagram of the light source unit in FIG. 15 as viewed from the −Z side.

The optical heating device of the present invention will be described below with reference to the drawings. Note that the following drawings of the optical heating device are all schematic illustrations, and the dimensional ratios and numbers in the drawings do not necessarily match the actual dimensional ratios and numbers.

[First embodiment]
Fig. 1 is a schematic cross-sectional view of a first embodiment of a light heating device 1 when viewed in the Y direction, and Fig. 2 is an enlarged view of a part of a light source unit 20 in Fig. 1. Also, Fig. 3 is a view of the light source unit 20 in Fig. 1 when viewed from the -Z side. As shown in Fig. 1, the light heating device 1 includes a chamber 10 and a light source unit 20.

The light source unit 20 includes a lamp house 21, four circle heaters 22 that are heating light sources, and four focusing optical systems 23 provided corresponding to each of the circle heaters 22. Note that there may be only one circle heater 22 and one focusing optical system 23, depending on the shape and size of each, the size of the object to be heated W1, etc.

FIG. 4A is a diagram of the circle heater 22 mounted on the light source unit 20 as viewed from the +Z side, and FIG. 4B is a diagram of the circle heater 22 as viewed from the +Y side.

In the following description, as shown in FIG. 1, the plane parallel to the main surface W1a of the heating object W1, which is the object to be heated and housed in the chamber 10, is defined as the XY plane, and the direction perpendicular to the XY plane is defined as the Z direction. In the present invention, no particular distinction is made between the X direction and the Y direction, but when describing the configuration of a heating light source such as the circle heater 22 shown in FIG. 4A and FIG. 4B, the X direction and the Y direction are defined appropriately according to the configuration of the heating light source. In the description of the circle heater 22 in the first embodiment, the direction in which the pair of electrodes (22c, 22c) of the circle heater 22 face each other is described as the Y direction.

In addition, when expressing a direction, if a distinction is made between positive and negative, it is written with a positive or negative sign, such as "+Z direction" and "-Z direction." When expressing a direction without distinguishing between positive and negative, it is simply written as "Z direction."

In addition, in the explanation of the first embodiment, it is assumed that the heating object W1 is a disk-shaped silicon wafer, but it is also envisioned that the optical heating device 1 of the present invention can be used to heat a heating object W1 other than a silicon wafer (e.g., a glass substrate, etc.).

As shown in FIG. 1, the chamber 10 includes a support member 12 for placing an object to be heated W1 inside, and a light-transmitting section 11 for guiding the heating light Lx emitted from the light source unit 20 to the inside.

The light-transmitting section 11 is formed on a part of the wall surface on the +Z side of the chamber 10, and takes in the heating light Lx emitted from the light source unit 20 arranged outside the chamber 10 into the inside of the chamber 10. In the first embodiment, the light-transmitting section 11 is made of quartz glass that is transparent to the heating light Lx.

In the first embodiment, as shown in FIG. 1, the light-transmitting portion 11 is formed on a portion of the wall surface of the chamber 10. However, for example, the upper surface and side surface of the chamber 10 may be made of quartz glass, and the entire upper surface and side surface of the chamber 10 may form the light-transmitting portion 11.

As shown in FIG. 1, the support member 12 is configured with a base 12a and multiple protrusions 12b, and the heating object W1 is placed and supported on the tips of the multiple protrusions 12b.

As shown in FIG. 1, the support member 12 of the first embodiment is provided with a rotation mechanism using multiple rollers 12c and is configured to be freely rotatable. When the heat treatment is performed, the rollers 12c rotate, and the heating object W1 can be rotated on the XY plane around an axis z1 that passes through the center of the support member 12 in the Z direction as the rotation axis.

Note that the support member 12 does not have to be configured to rotate the object to be heated W1 if the light source unit 20 is configured to irradiate the heating light Lx uniformly in the circumferential direction of the main surface W1a of the object to be heated W1. Also, the support member 12 may be configured to support the object to be heated W1 by hooking, for example, the peripheral portion of the object to be heated W1.

As shown in Figures 1 to 3, the lamp house 21 is a housing in which a space 21a is formed in which the circle heater 22 is housed. The lamp house 21 is made of aluminum, and the inner wall surface of the space 21a in which the circle heater 22 is housed is provided with reflective surfaces (21b, 21c) that reflect the heating light Lx emitted from the circle heater 22 and traveling in a direction different from the heating object W1 so that it travels toward the heating object (-Z side). In other words, the lamp house 21 corresponds to a reflective member. Note that the lamp house 21 is not limited to the above configuration, and may be configured, for example, by forming a metal film such as aluminum on the surface of a heat-resistant ceramic.

The reflective surfaces (21b, 21c) have a first reflective surface 21b that is circular and a second reflective surface 21c that is parabolic in cross section when cut along a plane perpendicular to the direction in which the space 21a extends, i.e., in the cross section shown in the XZ plane in Figure 2.

The first reflecting surface 21b reflects the heating light Lx emitted from the filament 22b in the radial direction of the light emitting tube 22a back toward the filament 22b and also reflects it directly toward the object to be heated W1.

The second reflecting surface 21c reflects the heating light Lx emitted from the filament 22b that is not incident on the first reflecting surface 21b and the focusing optical system 23 toward the heating object W1. In the first embodiment, the central axis of the filament 22b is arranged to coincide with the focal position of the second reflecting surface 21c so that the heating light Lx emitted from the filament 22b travels approximately parallel to the Z direction.

The shape of the reflective surfaces (21b, 21c) can be any shape depending on the shape of the heating light source, and may be only the first reflective surface 21b along a circular shape, or only the second reflective surface 21c along a parabolic shape. Furthermore, the shapes of the reflective surfaces (21b, 21c) are not limited to these shapes, and may be reflective surfaces along other curves such as an elliptical shape.

The circle heater 22 of the light source unit 20 of the first embodiment includes, as shown in Figures 4A and 4B, a light emitting tube 22a, a portion of which extends along an arc, a filament 22b disposed along the tube axis 22p of the light emitting tube 22a, and a pair of electrodes (22c, 22c) provided at both ends in the direction in which the light emitting tube 22a extends.

Heat lamps with this configuration are also called "double-ended type." Heat lamps in which both of the pair of electrodes are provided on one end of the light-emitting tube are also called "single-ended type."

In the first embodiment, the circle heater 22 is a halogen lamp that emits infrared light with a peak wavelength of 850 nm. For convenience of illustration, in Figs. 1 to 3, the pair of electrodes (22c, 22c) of the circle heater 22 are omitted, and the circle heater 22 is illustrated diagrammatically as a halogen lamp having a circular ring shape.

As shown in FIG. 4A, the arc tube 22a has a shape in which the tube axis 22p extends along a circular arc. The arc tube 22a is filled with an emitting gas containing a Group 18 element gas such as argon, krypton, or xenon. The circular shape along the tube axis 22p corresponds to the first circle C1.

In the first embodiment, the diameter of the circular heater 22 mounted on the light source unit 20 is 13 mm. The radii of the circular shape (first circle C1) along the tube axis 22p of the four light emitting tubes 22a are 27.5 mm, 62.5 mm, 97.5 mm, and 132.5 mm, respectively.

If the object to be heated W1 is disc-shaped, it is preferable that the light-emitting tube 22a has a shape in which at least a portion of it extends along an arc. However, for example, if the shape of the main surface W1a of the object to be heated W1 is a rectangular plate or the like, the light-emitting tube 22a may have a straight tube shape extending in one direction.

The arc tube 22a in the first embodiment is made of quartz glass.

The filament 22b is made by winding a wire of tungsten (W) and is arranged so that the central axis of the wound part coincides with the tube axis 22p of the light-emitting tube 22a. Although not shown in Figures 4A and 4B, the filament 22b is supported by a ring-shaped supporter so that its position within the light-emitting tube 22a is stable. The filament 22b may be made of a wire other than tungsten (W).

The pair of electrodes (22c, 22c) are inserted into holes provided in the lamp house 21 and connected to wiring provided on the +Z side of the lamp house 21. During operation, heating light Lx is emitted from the filament 22b when power is supplied from a power supply unit (not shown).

FIG. 5 is a perspective view showing a schematic shape of the focusing optical system 23. As shown in FIG. 5, the focusing optical system 23 in the first embodiment is a convex lens having a shape obtained by cutting a circular ring shape with a plane passing through the axis, and is an optical system that reduces the divergence angle in the Z direction of the heating light Lx emitted from the circle heater 22 toward the -Z side. The focusing optical system 23 having this configuration is also called a "circular ring cylindrical lens."

The focusing optical system 23 in the first embodiment has a planar entrance surface 23a and a convex exit surface 23b, as shown in Fig. 2 and Fig. 5. The locus of the focal position F1 of the focusing optical system 23 has a circular shape parallel to the XY plane, as shown in Fig. 5. This locus of the focal position F1 corresponds to a second circle C2.

The light heating device 1 of the first embodiment is configured so that the first circle C1 and the second circle C2 are concentric when viewed in the Z direction. As shown in FIG. 2, the light heating device 1 of the first embodiment is configured so that the focal position F1 of the focusing optical system 23 along the second circle C2 is inside the tube axis 22p of the light emitting tube 22a along the first circle C1. In other words, the radius of the second circle C2 is configured to be smaller than the radius of the first circle C1.

The radius of the second circle C2 may be configured to be the same as or larger than the radius of the first circle C1 for the purpose of adjusting the illuminance distribution on the heated object W1.

[Verification experiment]
Here, a verification experiment was carried out to confirm that the use efficiency of the heating light Lx on the main surface W1a of the heating object W1 is improved by installing a focusing optical system, and details thereof will be described below.

Example 1
The first embodiment is a light heating device 1 having the configuration shown in FIG.

Example 2
6A is a schematic cross-sectional view of one embodiment of the light heating device 1 when viewed in the Y direction. In the second embodiment, the tube axis 22p of the light emitting tube 22a and the focal position F1 of the light collecting optical system 231 are arranged along the Z direction. That is, the light heating device 1 in the second embodiment is configured such that the first circle C1 and the second circle C2 coincide with each other when viewed from the Z direction. Except for the above points, the second embodiment has the same configuration as the first embodiment.

Comparative Example
6B is a schematic cross-sectional view of the optical heating device 100 when viewed in the Y direction. The optical heating device 100 as a comparative example has the same configuration as that of Example 1, except that a light source unit 200 not provided with a light collecting optical system 23 is mounted instead of the light source unit 20.

(conditions)
Assuming that a silicon wafer with a diameter of 300 mm was to be heated, the illuminance of the heating light Lx was measured within a radius of 150 mm, with the origin being a point passing through the axis z1 (see FIG. 1) on the main surface of the silicon wafer at a position 450 mm away from the circle heater 22 in the Z direction. The heat quantity ratio, which is a parameter to be compared, was calculated as a relative value of Example 1 and Example 2 when the result of the comparative example was taken as 100%, with respect to the amount of heat absorbed by the heated object calculated based on the measured illuminance distribution when the circle heaters 22 mounted on the light source units of each of Example 1, Example 2, and Comparative Example were turned on by supplying the same power to them.

(result)
The results are as shown in Table 1 below.

As can be seen from Table 1 above, in Examples 1 and 2, the amount of heat absorbed by the heated object W1 is greater than in the comparative example. In other words, it is confirmed that Examples 1 and 2 have a higher utilization efficiency of the heating light Lx emitted from the circle heater 22 than in the comparative example.

Figure 7 is a graph showing the illuminance distribution in the X direction for Example 1 and the Comparative Example. As shown in Figure 7, it is also confirmed that the illuminance distribution of the heating light Lx irradiated onto the main surface of the silicon wafer is generally higher in Example 1 than in the Comparative Example.

As a result, the optical heating device 1 configured as described above is less likely to advance to the outside of the object to be heated W1, and more heating light Lx is irradiated onto the object to be heated W1, compared to an optical heating device of a conventional configuration that does not have a focusing optical system.

Furthermore, by configuring the corresponding heating lamp and focusing optical system so that the radius of the second circle C2 is smaller than the radius of the first circle C1, the amount of heat absorbed by the heated object W1, i.e., the light energy, is increased more than when the radius of the second circle C2 and the radius of the first circle C1 are configured to be the same.

Here, we will explain the configuration for which the optical heating device 1 is particularly suitable. Figure 8 is a diagram that shows a schematic representation of the positional relationship between the light source unit 20 and the object to be heated W1. Note that the light source unit 20 shown in Figure 8 has the same configuration as the light source unit 20 provided in the optical heating device 1 described above, and is disposed in the same positional relationship with respect to the object to be heated W1, but for ease of explanation, the positional relationship with respect to the object to be heated W1 is illustrated differently from that shown in Figure 1 etc.

As shown in FIG. 8, if the distance between the tube axis 22p of the arc tube 22a and the main surface W1a of the object to be heated W1 is WD, the distance between the tube axis 22p and the peripheral end W1b of the object to be heated W1 is D1, the angle at which a line connecting the tube axis 22p and the peripheral end W1b of the object to be heated W1 is inclined with respect to the Z direction is θ _W , and the angle at which a line connecting the tube axis 22p and the reflective end 21p is inclined with respect to the Z direction is θ _R , the arc tube 22a, the lamp house 21, and the object to be heated W1 are disposed in a positional relationship that satisfies θ _W < θ _R regardless of the magnitude of the distance WD.

FIGS. 9A and 9B are diagrams showing an example of a configuration of the focusing optical system 23 that is different from the above configuration. In the first embodiment, a focusing optical system 23 having a circular ring shape is installed, but as shown in FIG. 9A, it is also possible to configure the focusing optical system 23 to have a circular ring shape as a whole by using multiple focusing optical systems 23.

Also, as shown in FIG. 9B, a plurality of focusing optical systems 23 mounted on the light source unit 20 may be arranged concentrically and integrally configured on a plate 23p made of a material that is transparent to the heating light Lx (not shown). Each of these focusing optical systems 23 has a shape that extends along an arc.

[Second embodiment]
The configuration of the second embodiment of the light heating device of the present invention will be described, focusing on the differences from the first embodiment.

FIG. 10 is an enlarged view of a portion of the light source unit 20 in the second embodiment of the optical heating device 1, and FIG. 11 is a view of the light source unit 20 in the second embodiment of the optical heating device 1 as viewed from the -Z side. As shown in FIG. 10, the second embodiment of the optical heating device 1 is equipped with multiple LEDs 24, which are solid-state light sources, as heating light sources.

In the second embodiment, the radius of the second circle C2, which is the locus of the focal position F1 of the corresponding focusing optical system 23, is smaller than the radius of the first circle C1 along the center point 24a of the LEDs 24 arranged on the same circumference.

In the second embodiment, the light source unit 20 has a circular focusing optical system 23 arranged for multiple LEDs 24 arranged on the same circumference, but the light source unit 20 may be configured to include a collimating lens corresponding to each of the multiple LEDs 24, for example.

[Another embodiment]
Another embodiment will be described below.

<1> Fig. 12 is a cross-sectional view of another embodiment of the light heating device 1 when viewed in the Y direction, and Fig. 13 is a drawing of the light source unit 20 of Fig. 12 when viewed from the -Z side. The light source unit 20 may be equipped with a flash lamp 25, which is a type of heating lamp. As shown in Fig. 13, the flash lamp 25 has a straight light-emitting tube 22a and is equipped with a pair of discharge electrodes (25c, 25c) at both ends in the Y direction to which it extends.

<2> Figure 14 is a schematic enlarged cross-sectional view of the light source unit 20 in an embodiment of the light heating device 1 different from that in Figure 12, when viewed in the Y direction. As shown in Figure 14, the light source unit 20 may be equipped with a heat lamp 26 in which the light emitting tube 26a and the collective optical system 26b are integrally configured.

By using the above configuration, the light source unit 20 can be made smaller.

<3> Figure 15 is a schematic enlarged cross-sectional view of a light source unit in an embodiment of the light heating device 1 different from those in Figures 12 and 14, when viewed in the Y direction, and Figure 16 is a drawing of the light source unit 20 in Figure 15 when viewed from the -Z side. Note that for ease of explanation, Figure 16 does not show the focusing optical system 29. As shown in Figure 15, the light source unit 20 is equipped with multiple light bulbs 28, which are single-ended heating lamps, and each light bulb 28 is equipped with multiple focusing optical systems 29 that are circular when viewed from the Z direction.

In addition, in this embodiment, the lamp house 27 has multiple spaces 27a with circular openings when viewed from the Z direction, and the light bulbs 28 are housed in each of the spaces 27a.

As can be seen from Figures 15 and 16, the space 27a has a reflective surface 27b whose inner wall surface conforms to a spherical surface, and a reflective surface 27c whose inner wall surface conforms to a paraboloid of revolution.

In this embodiment, the light bulb 28 is installed as a single-ended heat lamp, but a single-ended heat lamp separate from the light bulb 28 may also be installed. For example, a single-ended halogen lamp with a long bulb may also be used.

In addition, the shapes of the reflecting surfaces (27b, 27c) are not limited to these shapes, and may be reflecting surfaces that conform to the surfaces of other rotating bodies, such as ellipsoids of revolution.

〈4〉 The configuration of the light heating device 1 described above is merely an example, and the present invention is not limited to the configurations shown in the drawings.

1: Light heating device 10: Chamber 11: Light-transmitting portion 12: Support member 12a: Base 12b: Protrusion 12c: Roller 20: Light source unit 21: Lamp house 21a: Space 21b, 21c: Reflecting surface 22: Circle heater 22a: Arc tube 22b: Filament 22c: Electrode 22p: Tube axis 23: Light-collecting optical system 23a: Incident surface 23b: Emitting surface 23p: Plate 24: LED
24a: Center point 25: Flash lamp 25a: Arc tube 25c: Discharge electrode 26: Heat lamp 26a: Arc tube 26b: Light collecting optical system 27: Lamp house 27a: Space 27b, 27c: Reflecting surface 28: Light bulb 29: Light collecting optical system 100: Light heating device 200: Light source unit W1: Substrate to be processed W1a: Second main surface

Claims

A light heating device that irradiates a heating object with heating light,
A chamber in which the object to be heated is accommodated;
a light source unit disposed outside the chamber and configured to emit the heating light toward the object to be heated;
a light transmitting portion for introducing the heating light emitted from the light source unit into the inside of the chamber,
The light source unit includes:
A heating light source that emits the heating light;
a reflecting member that reflects a portion of the heating light emitted from the heating light source and traveling in a direction different from the object to be heated, toward the object to be heated;
An optical heating device comprising: a focusing optical system that reduces the divergence angle of the heating light emitted from the heating light source toward the object to be heated in a direction in which the heating light source and the chamber face each other.
The optical heating device according to claim 1, characterized in that the heating light source is a heating lamp having a long arc tube and a pair of electrodes provided at both ends in the direction in which the arc tube extends.
The optical heating device according to claim 2, characterized in that the focusing optical system and the light emitting tube are integrally constructed.
The optical heating device according to claim 2, characterized in that the heating light source is a halogen lamp.
The optical heating device according to claim 2, characterized in that the heating light source is a flash lamp.
The light heating device according to claim 2, characterized in that the light emitting tube of the heating light source has a straight tube shape.
The optical heating device according to claim 2, characterized in that at least a portion of the light-emitting tube of the heating light source extends along an arc.
The optical heating device according to claim 7, characterized in that the focusing optical system has a shape that extends along an arc, and when viewed from the chamber, a first circle along the tube axis of the arc-extending portion of the light-emitting tube of the heating light source and a second circle along the locus of the focal position of the focusing optical system are concentric with each other with respect to the heating light source and the focusing optical system.
The optical heating device of claim 8, characterized in that the radius of the second circle is smaller than the radius of the first circle when viewed from the chamber.
The light heating device according to claim 2, characterized in that the reflecting member extends along the tube axis of the light-emitting tube and has a reflecting surface whose cross-sectional shape when cut along a plane perpendicular to the direction in which the reflecting member extends is parabolic, elliptical, or circular.
The optical heating device according to claim 1, characterized in that the heating light source is a single-ended heating lamp.
The optical heating device according to claim 11, characterized in that the reflecting member has a reflecting surface along a paraboloid of revolution, an ellipsoid of revolution, or a sphere.
The optical heating device according to claim 1, characterized in that the heating light source includes a plurality of solid-state light sources.
14. The light heating device according to claim 13, wherein the light collecting optical system is provided corresponding to each of the plurality of solid-state light sources.