Heating lamp, heating light source unit, and optical heating device

Abstract

To provide a heating lamp, a heating light source unit, and a light heating device that are easy to manufacture and can irradiate a heated object with high-intensity, homogeneous light without increasing the size of the entire device.SOLUTION: A heating lamp includes a tube body including a first tube wall having a tube axis extending linearly or curved and having an arcuate cross section when cut along a plane perpendicular to the tube axis, a light emitter disposed within the tube and extending along the tube axis, and a reflective film that is provided on at least a portion of the first tube wall so as to extend along the tube axis, and that reflects the light emitted from the light emitter, and when viewed in the direction along the tube axis, when the radius of curvature of the reflective surface of the reflective film facing the light emitter is R, and the distance between the center of curvature of the reflective surface and the central axis of the light emitter is d, the light emitter is arranged within the tube body at a position that satisfies a predetermined relational expression.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a heating lamp, a heating light source unit, and a light heating device.

Background Art

[0002] In semiconductor manufacturing processes, various heat treatments such as film formation, oxidation diffusion, modification, and annealing treatments are performed on objects to be heated such as semiconductor wafers. Many of these treatments employ a heat treatment method using light irradiation that enables non-contact treatment. As a heating device used in semiconductor manufacturing processes, depending on the required heat treatment temperature, a heating device equipped with a halogen lamp as a heating light source (hereinafter referred to as a "light heating device") is often adopted.

[0003] [[ID=第十六]]

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The inventors of the present invention have been earnestly studying further improvements to light heating devices and have found that the following problems exist in the heating lamps mounted on conventional light heating devices. The following will be described while referring to the drawings.

[0006] Figure 14 is a schematic diagram of a conventional optical heating device 101 viewed in the Y direction, and Figure 15 is a diagram of the optical heating device 101 in Figure 14 viewed in the X direction. Conventionally, as shown in Figures 14 and 15, the heating lamp 110 mounted on the optical heating device 101 is configured such that the tube axis 111c of the tube body 111 and the central axis 112c of the filament 112 coincide, and a reflective film 113 is provided on the outer wall surface 111a of the tube body 111 on the side opposite to the object to be heated W1 (+Z side).

[0007] In the following explanation, as shown in Figures 14 and 15, the plane parallel to the light irradiation surface W1a of the object to be heated W1 is defined as the XY plane, and the direction perpendicular to the light irradiation surface W1a is defined as the Z direction. With respect to the XY plane, the direction parallel to the tube axis 111c of the tube body 111 is defined as the X direction, and the direction perpendicular to the tube axis 111c is defined as the Y direction.

[0008] Furthermore, when expressing direction, if positive and negative directions need to be distinguished, they are written with positive or negative signs, such as "+Z direction" or "-Z direction." When expressing direction without distinguishing between positive and negative directions, it is simply written as "Z direction."

[0009] For the sake of explanation, we assume that the light emitted from the filament 112 travels isotropically in the radial direction of the tube 111 and is not obstructed by the filament 112. The light emitted from the filament 112, traveling radially through the tube 11 to the reflective film 113, is reflected back to the filament 112 by the reflective surface 113a, as shown in Figure 15. The light (L1, L2) reflected by the reflective surface 113a then reaches the outer wall surface 111a on the side where the reflective film 113 is not provided (-Z side), and is emitted from the tube 11 towards the -Z side.

[0010] In this case, light L2, which is tilted more sharply with respect to the Z direction than light L1, travels towards the -Z direction as well as in the ±Y directions. As a result, depending on the shape and size of the object to be heated W1, as shown in Figure 15, some of the light L2 may irradiate the outside of the object to be heated W1. In other words, in the configuration of the conventional heating lamp 110, although a reflective film 113 is provided to make use of more of the light emitted from the filament 112, there were cases where reflected light did not irradiate the object to be heated W1.

[0011] Therefore, the inventors diligently studied the configuration of the heating lamp 110 in order to improve the utilization efficiency of the light emitted from the filament 112, so as to irradiate the object W1 to be heated with more light.

[0012] First, as a method to increase the illuminance of the reflected light irradiated onto the light-irradiated surface W1a of the object to be heated W1, one could consider, for example, providing a reflective film 113 on a part of the outer wall surface 111a on the -Z side to narrow the area from which light (L1, L2) is extracted. However, restricting the area from which light (L1, L2) is extracted reduces the amount of light extracted from the tube 111, which would actually lead to a decrease in the illuminance on the light-irradiated surface W1a of the object to be heated W1.

[0013] Alternatively, one could fabricate a tube 111 with an elliptical cylindrical shape and form a reflective film 113 such that the light L2 is directed toward the central part of the light-irradiated surface W1a of the object W1 to be heated. However, if the shape of the tube 111 is adjusted to control the shape of the reflective surface 113a formed on the outer wall surface 111a and to concentrate the reflected light to a specific position, a high level of processing precision is required to always manufacture the tube 111 with the same shape. For this reason, this method is not practical as it would lead to increased manufacturing costs and a significant decrease in the production efficiency of the heating lamp.

[0014] Another possible approach is to provide a reflective element that exhibits the desired shape without using a reflective film. However, providing a separate reflective element would lead to an increase in the overall size of the optical heating device. Furthermore, if the overall shape and size of the optical heating device are fixed by specifications, it may be necessary to reduce the number of heating lamps in order to secure space for the reflective element, which could lead to insufficient light output.

[0015] In view of the above problems, the present invention aims to provide a heating lamp, a heating light source unit, and a light heating device that are easy to manufacture and can irradiate an object to be heated with high-intensity, uniform light without increasing the overall size of the device. [Means for solving the problem]

[0016] The heating lamp of the present invention is A pipe body having a pipe axis that extends in a straight or curved shape, and including a first pipe wall whose cross-section when cut by a plane perpendicular to the pipe axis is arc-shaped, A light-emitting element is placed inside the tube and extends along the axis of the tube, The first tube wall is provided with a reflective film that reflects light emitted from the light-emitting element, which is provided on at least a portion of the tube wall so as to extend along the tube axis, The light-emitting element is characterized in that, when viewed in the direction along the axis of the tube, the radius of curvature of the reflective surface of the reflective film that faces the light-emitting element is R, and the distance between the center of curvature of the reflective surface and the central axis of the light-emitting element is d, the light-emitting element is positioned within the tube at a location that satisfies the following equation (1). R / 2≦d <R (1)

[0017] In this specification, "light-emitting body" refers to a long, slender member that emits light for heating an object when power is supplied to it. Specific examples may include a filament, a metal rod or wire made of tungsten, molybdenum, or nichrome, or a rod-shaped member made of carbon or graphite.

[0018] In this specification, "viewed in the direction along the tube axis" means, when the tube body has a linearly extending shape, it is synonymous with viewing in the tube axis direction. When the tube body has a curved shape, it means viewing in the tangent direction at any point on the tube axis. In other words, "viewed in the direction along the tube axis" means viewing the tube body in the tube axis direction, or cutting the tube body with a plane orthogonal to the tangent direction of the tube axis at the arbitrary point and viewing the cut surface in the tangent direction (see FIGS. 12 and 13).

[0019] Also, in this specification, the radius of curvature R of the reflecting surface is determined based on the curvature at the position closest to the central axis of the filament of the reflecting surface in the cut surface when cut with a plane orthogonal to the tube axis.

[0020] The inventors have found that, depending on the position of the light emitter in the tube body provided with a reflective film on the wall surface having a cylindrical shape, the amount of light traveling toward the heating object and the illuminance distribution on the light irradiation surface change. And through intensive studies, it has been found that by arranging the light emitter at a position satisfying the above formula (1), compared with the configuration of a conventional heating lamp, it is possible to irradiate the light irradiation surface of the heating object with higher illuminance and to irradiate with a more uniform illuminance distribution. Details of how such effects are obtained will be described later while referring to the results of verification experiments in the section "Modes for Carrying Out the Invention".

[0021] That is, by having the above configuration, the heating lamp can irradiate more light from the light emitter to the heating object, and can irradiate the light irradiation surface of the heating object with a uniform illuminance distribution. Also, for the light heating device, if it mounts a heating lamp having such a configuration, there is no need to separately provide a reflecting member, so an increase in the size of the entire device is avoided.

[0022] The above heating lamp is preferably arranged such that when viewed in the direction along the tube axis, the light emitter satisfies the following formula (2) within the tube body. (R / 2)×1.1 ≦ d ≦ (R / 2)×1.3 (2)

[0023] In the heating lamp, The reflection film may be formed on the inner wall surface side of the first pipe wall.

[0024] With the above configuration, even if the reflection film peels off from the wall surface of the pipe body by chance, the fragments of the peeled-off reflection film will remain inside the pipe body and will not fall onto the light irradiation surface of the object to be heated. That is, the heating lamp with the above configuration can prevent the peeled-off reflection film from soiling the object to be heated.

[0025] In the heating lamp, The pipe body may include a second pipe wall that linearly connects one end and the other end of the first pipe wall that呈 an arc shape when viewed in the direction along the pipe axis.

[0026] The pipe body included in the heating lamp with the above configuration can be easily manufactured by, for example, preparing a pipe body with a cylindrical shape, heating the pipe body until it becomes deformable, and then pressing a part of the pipe wall against a flat surface.

[0027] Furthermore, in the heating lamp, The reflection film may be formed from the one end to the other end of the first pipe wall when viewed in the direction along the pipe axis.

[0028] According to the above configuration, in an optical heating device including a plurality of heating lamps, most of the light emitted from a heating lamp and traveling toward an adjacent other heating lamp hits the reflection film. Therefore, the adjacent heating lamps 10 are suppressed from irradiating and heating each other with light. As a result, the optical heating device can achieve a long service life and high reliability.

[0029] Furthermore, in the heating lamp, The second pipe wall may be formed thicker than the first pipe wall.

[0030] In the above heating lamp, The main material of the reflective film may be at least one selected from the group consisting of silica (SiO2), alumina (Al2O3), titania (TiO2), and boron nitride (BN).

[0031] Furthermore, in the above heating lamp, The main material of the reflective film may be at least one metal selected from the group consisting of aluminum (Al), copper (Cu), gold (Au), and rhodium (Rh).

[0032] In the above heating lamp, The light-emitting element is a filament, and the main material of the filament may be at least one selected from the group consisting of graphite, carbon, tungsten, nichrome, platinum, molybdenum, and iron-chromium.

[0033] In this specification, "main material" refers to the material that has the highest content among all the materials included.

[0034] The heating light source unit of the present invention is It is characterized by being equipped with multiple heating lamps as described above.

[0035] The optical heating device of the present invention is A chamber for containing the object to be heated, The invention is characterized by comprising at least one heating lamp that emits light toward the object to be heated, which is housed within the chamber. [Effects of the Invention]

[0036] According to the present invention, a heating lamp, a heating light source unit, and a light heating device are realized that are easy to manufacture and can irradiate an object to be heated with high-intensity, uniform light without increasing the overall size of the device. [Brief explanation of the drawing]

[0037] [Figure 1] This is a schematic diagram of one embodiment of a light heating device as viewed in the Y direction. [Figure 2] This is a schematic diagram of the optical heating device shown in Figure 1, viewed in the X direction. [Figure 3] This is a view of the heating lamp mounted on the optical heating device shown in Figure 1, as seen in the Y direction. [Figure 4] This is a view of the heating lamp mounted on the optical heating device shown in Figure 1, as seen in the X direction. [Figure 5A] This diagram schematically shows the state of the verification experiment as viewed in the Y direction. [Figure 5B] This diagram schematically shows the state of the verification experiment as viewed from the +Z side. [Figure 6] This graph shows a portion of the illuminance distribution obtained from the verification experiment. [Figure 7] This is a diagram of Figure 4, but with the -Z direction replaced by the +y direction and the +Y direction replaced by the +x direction. [Figure 8] This is a schematic diagram of one embodiment of a light heating device as viewed in the Y direction. [Figure 9] Figure 8 is a schematic diagram of the optical heating device as viewed in the X direction. [Figure 10] Figure 8 shows a view of the heating lamp mounted on the optical heating device, as seen in the X direction. [Figure 11] This is a diagram showing the heating lamp in the X direction in another embodiment of the optical heating device. [Figure 12] This is a diagram showing the heating lamp in another embodiment of the optical heating device, viewed in the Z direction. [Figure 13] Figure 12 is a cross-sectional view of the heating lamp shown in AA. [Figure 14] This is a schematic diagram of a conventional optical heating device viewed in the Y direction. [Figure 15] Figure 14 shows the optical heating device as viewed in the X direction. [Modes for carrying out the invention]

[0038] [First Embodiment] The photothermal heating apparatus and heat treatment method of the present invention will be described below with reference to the drawings. Note that the following drawings relating to the photothermal heating apparatus are schematic illustrations, and the dimensional ratios and numbers shown in the drawings do not necessarily correspond to the actual dimensional ratios and numbers.

[0039] Furthermore, in the following description of the configuration of the optical heating device, the object to be heated may be specifically identified. However, the object to be heated by the optical heating device of the present invention is not limited to the objects to be heated identified in the following description.

[0040] (Light heating device 1) Figure 1 is a schematic diagram of the first embodiment of the optical heating device 1 as viewed in the Y direction, and Figure 2 is a diagram of the optical heating device 1 of Figure 1 as viewed in the X direction. As shown in Figures 1 and 2, the optical heating device 1 of the present invention comprises a chamber 2, a support member 3, and a heating light source unit 4.

[0041] In the following explanation, as shown in Figures 1 and 2, the plane parallel to the light irradiation surface W1a of the object to be heated W1 is defined as the XY plane, and the direction perpendicular to the light irradiation surface W1a is defined as the Z direction. With respect to the XY plane, the direction parallel to the tube axis 11c of the tube body 11 is defined as the X direction, and the direction perpendicular to the tube axis 11c is defined as the Y direction.

[0042] Furthermore, when expressing direction, if positive and negative directions need to be distinguished, they are written with positive or negative signs, such as "+Z direction" or "-Z direction." When expressing direction without distinguishing between positive and negative directions, it is simply written as "Z direction."

[0043] Chamber 2 has a processing chamber 2a formed inside, which is equipped with a support member 3 for supporting the object to be heated W1. In the first embodiment, the optical heating device 1 performs the heating treatment of the object to be heated W1 by creating a vacuum inside the processing chamber 2a, but the heating treatment of the object to be heated W1 may also be performed in a non-vacuum state. Furthermore, when performing the heating treatment, the chamber 2 may be configured so that the processing chamber 2a is filled with an inactivated gas such as nitrogen or a noble gas (rare gas) depending on the type of object to be heated W1, or it may be kept open at all times to allow outside air to enter and exit.

[0044] As shown in Figures 1 and 2, the support member 3 is provided with a plurality of protrusions 3a, and the object to be heated W1 is placed on the tip of each protrusion 3a and supported. However, the configuration of the support member 3 is not limited to support by a plurality of protrusions 3a, and may also be a configuration that grips and supports both ends of the object to be heated W1, or a configuration that supports only the peripheral ends of the object to be heated W1, etc.

[0045] As shown in Figure 2, the heating light source unit 4 includes multiple heating lamps 10 arranged in the Y direction. However, if sufficient heating can be achieved with a single heating lamp 10, the light source of the optical heating device 1 may be a single heating lamp 10 instead of the heating light source unit 4 with multiple heating lamps 10.

[0046] (Heating lamp 10) Figure 3 is a view of the heating lamp 10 mounted on the optical heating device 1 of Figure 1 in the Y direction, and Figure 4 is a view of the heating lamp 10 mounted on the optical heating device 1 of Figure 1 in the X direction. As shown in Figures 3 and 4, the heating lamp 10 is a halogen lamp comprising a tube 11, a filament 12 which is a light-emitting element, a reflective film 13, a supporter 14, and a pair of pinch seals (15, 15) provided at both ends of the tube 11.

[0047] As shown in Figures 3 and 4, the tube 11 is a component that houses the filament 12 inside. In the first embodiment, the tube 11 has a cylindrical shape that extends in a straight line and is made of glass that is transparent to the light emitted from the filament 12. As shown in Figure 4, the tube 11 consists only of a first tube wall 11p that has an arc shape when viewed in the direction along the tube axis 11c (X direction).

[0048] The space within the tube 11 where the filament 12 is located is hermetically sealed and filled with halogen gas and inert gas.

[0049] Furthermore, in the first embodiment, the inner diameter of the tube 11 is 14 mm. In the light heating device 1 of the first embodiment, the distance between the centers of the tubes 11 is 20 mm in the Y direction, that is, adjacent heating lamps 10 are arranged to be 4 mm apart from each other.

[0050] In the first embodiment, the filament 12 is a coil-shaped light-emitting body made by winding a wire so that its diameter is 2 mm when viewed in the direction along the central axis 12c (X direction). The filament 12 emits light when power is supplied from a power supply device (not shown) connected via metal foil provided in the pinch seal portions (15, 15).

[0051] In the first embodiment, the filament 12 is primarily made of tungsten. The primary material of the filament 12 can be any material that emits light when power is supplied, for example, a metal material can be used. However, considering the high intensity of the emitted light relative to the supplied power, graphite, carbon, tungsten, nichrome, platinum, molybdenum, and iron-chromium are preferred. Furthermore, instead of a filament, the light-emitting element housed in the tube 11 may be, for example, a metal rod or wire made of tungsten, molybdenum, or nichrome, or a rod-shaped member made of carbon or graphite.

[0052] In the first embodiment, as shown in Figure 4, the reflective film 13 is an inorganic particle film whose main material is silica (SiO2), provided on the inner wall surface 11b on the +Z side of the tube body 11, and the surface facing the filament 12 forms a reflective surface 13a that reflects the light L1 emitted from the filament 12. In the first embodiment, the center of curvature Cp of the reflective surface 13a coincides with the tube axis 11c of the tube body 11.

[0053] The reflective film 13 may also be formed on the outer wall surface 11a of the pipe body 11. Furthermore, for illustrative purposes, the thickness of the reflective film 13 in Figure 4 is shown as being the same as the thickness of the pipe wall of the pipe body 11, but the actual thickness is 0.05 to 0.2 mm, which is significantly thinner than the pipe wall of the pipe body 11.

[0054] Furthermore, although the reflective film 13 in this embodiment is an inorganic particle film whose main material is silica (SiO2), the main material of the inorganic particle film forming the reflective film 13 is preferably silica, Al2O3 (alumina), TiO2 (titania), or BN (boron nitride), considering the reflectivity to light used to heat the object W1 to be heated. Furthermore, the reflective film 13 may also be composed of a thin metal film, and the main material is preferably a metal film such as aluminum (Al), copper (Cu), gold (Au), or rhodium (Rh), considering the reflectivity to light used to heat the object W1 to be heated.

[0055] The supporter 14 is a component that maintains the filament 12 in a predetermined position within the tube 11. In the heating lamp 10 of the first embodiment, as shown in Figure 3, three supporters 14 are arranged in the X direction, but the number of supporters 14 is arbitrary. Also, if the length of the tube 11 in the X direction is short and the filament 12 can maintain its position within the tube 11 by itself, the supporter 14 may not be provided.

[0056] In the first embodiment, the filament 12 is positioned by a supporter 14 (not shown in Figure 4) at a location that satisfies equation (2) above, where R is the radius of curvature of the reflective surface 13a and d is the distance between the center of curvature Cp of the reflective surface 13a and the central axis 12c of the filament 12 when viewed in the direction along the tube axis 11c (X direction). For the sake of clarity, equation (2) above is reproduced below. (R / 2)×1.1≦d≦(R / 2)×1.3 (2)

[0057] In the first embodiment, specifically, the radius of curvature R of the reflective surface 13a in region C1 shown in Figure 4 is 7.0 mm, and the distance d is 4.0 mm. However, since the first tube wall 11p on which the reflective film 13 is formed is arc-shaped, the radius of curvature R of the reflective surface 13a is almost constant in any region, regardless of whether it is region C1 or not. Furthermore, as mentioned above, the radius of curvature R in the first embodiment is substantially equivalent to half the inner diameter of the tube 11, given that the thickness of the reflective film 13 is very thin.

[0058] The filament 12 only needs to satisfy, at least, equation (1) above, in terms of its radius of curvature R and distance d when viewed in the X direction. Note that if equation (2) above is satisfied, then equation (1) above is necessarily satisfied. For clarification, equation (1) above is reiterated. R / 2≦d <R (1)

[0059] [Verification experiment] Here, in the configuration of the heating lamp 10 of the first embodiment, a verification experiment was conducted to confirm how the cumulative illuminance within a predetermined range on the light-irradiated surface W1a of the object to be heated W1 and the homogeneity of the illuminance distribution change when the distance d is changed. Details of this verification experiment will now be explained.

[0060] (Verification method) Figure 5A is a schematic diagram showing the verification experiment as viewed in the Y direction, and Figure 5B is a schematic diagram showing the verification experiment as viewed from the +Z side. The illuminance distribution was obtained by measuring the illuminance while moving the illuminance meter M1 in parallel over a range of ±50 mm in the Y direction, with the reference point Mp being 100 mm away from the center Bp of the tube 11 in the -Z direction, as shown in Figures 5A and 5B.

[0061] The reason for setting the distance between the heating lamp 10 and the illuminance meter M1 to 100 mm is that this distance is relatively commonly used as the distance between the heating lamp and the semiconductor wafer in optical heating devices used to heat semiconductor wafers.

[0062] Assuming that the diameter of the tube 11 is 14 mm and that each heating lamp 10 in the light heating device 1 is arranged to be 4 mm apart, the cumulative illuminance was defined as the integral value of the illuminance within a range of ±10 mm in the Y direction from the reference point Mp. For the determination, the relative value P1 was normalized by setting the cumulative illuminance at a distance d of 3.5 mm to 100.

[0063] In determining the homogeneity of the illuminance distribution, the value P2 obtained by equation (3) below, based on the illuminance within a range of ±10 mm in the Y direction, was used for the judgment. Max and Min are the maximum and minimum illuminance values ​​in the illuminance distribution within that range. The smaller the value P2, the more homogeneous the illuminance distribution is. P2=(Max-Min) / {(Max+Min) / 2}×100 (3)

[0064] In this verification, the relative values ​​P1 and P2 were confirmed when the distance d was varied in 0.1 mm increments within the range of 3.5 mm to 4.6 mm. The configuration of this embodiment is as follows when the distance d is 4.0 mm. Furthermore, for the range where the distance d is less than 3.5 mm, the relative values ​​P1 and P2 were confirmed for distances d of 0.0 mm, 0.5 mm, 1.5 mm, and 2.5 mm as comparative examples (see Table 1 below).

[0065] In this embodiment, if one were to actually manufacture a heating lamp with a configuration where d / (R / 2) is 1.3 or greater, i.e., a distance d of 4.6 mm or greater, it would be difficult to ensure a distance of 1 mm or more between the filament and the reflective film. Heating lamps with such configurations are prone to the filament coming into contact with the reflective film during manufacturing, damaging the reflective surface, and thus become extremely difficult to manufacture. Furthermore, even if manufacturing were possible, vibrations during transportation or use could cause the filament and reflective film to come into contact, leading to the aforementioned problems. For these reasons, considering reliability and other factors, and from the perspective of the difficulty of actually manufacturing such a product, as well as from the perspective of confirming the difference between cases where d / (R / 2) is greater than 1.3 and cases where it is less than 1.3, this verification was conducted in a range where the distance d of the heating lamp 10 is less than 4.6 mm.

[0066] The illuminance on the light-irradiated surface W1a of the object to be heated W1 affects whether or not the object to be heated W1 can be heated. Therefore, in order to heat-treat a wider variety of objects to be heated W1, especially semiconductor wafers that require high-temperature heating, it is preferable to have a higher integrated illuminance within a predetermined area. Accordingly, the relative value P1 of the integrated illuminance was checked using whether the relative value P1 was higher than that of a sample with a distance d of 3.5 mm as a reference. If the relative value P1 was greater than that of the sample with a distance d of 3.5 mm, it was judged as "A" indicating "good," and if the relative value P1 was smaller than that of the sample with a distance d of 3.5 mm, it was judged as "B" indicating "poor."

[0067] Regarding homogeneity, if the distance d was smaller than that of the 3.5mm sample, it was judged as "Excellent" ("A"). If the distance d was larger than that of the 3.5mm sample, but the difference with the value P2 of that sample was less than 10, and equivalent homogeneity was deemed to be ensured, it was judged as "Good" ("B"). If the value P2 was 10 or more greater than that of the 3.5mm sample, i.e., almost double, it was judged as "Poor" ("C").

[0068] First, the present invention aims to achieve light irradiation at a higher illuminance. In light of this, even if the homogeneity is good, if the relative value P1 is lower than the relative value P1 of a configuration where the distance d is at least 3.5 mm, it is difficult to judge the overall result as good. For this reason, if the cumulative illuminance judgment result is "B", the overall judgment was judged as "C", indicating "Poor", regardless of the homogeneity judgment result. Next, if the cumulative illuminance judgment result is "A" and the homogeneity judgment result is "B", the overall judgment was judged as "B", indicating "Good". And, if the cumulative illuminance judgment result is "A" and the homogeneity judgment result is "A", the overall judgment was judged as "Excellent".

[0069] (result) Figure 6 is a graph showing a portion of the illuminance distribution obtained in the verification experiment. Table 1 below shows the relative value P1, which is the parameter of integrated illuminance, and the value P2, which is the parameter of homogeneity, obtained from the illuminance distribution measured for each sample. In order to make it easier to understand the range that satisfies equation (2) above, Table 1 includes a column for the value obtained by dividing d by (R / 2).

[0070] [Table 1]

[0071] According to Table 1 above, it is confirmed that the relative value P1 decreases sharply when the filament 12 is positioned in a location that does not satisfy equation (1) above. Furthermore, it is confirmed that the value P2 becomes less than 10 when the distance d is in the range of (R / 2) × 1.1 or greater, i.e., when the filament 12 is positioned in a location that satisfies equation (2) above.

[0072] Here, we will consider the reasons why the above results were obtained. Figure 7 is a diagram of Figure 4, but with the -Z direction replaced by the +y direction and the +Y direction replaced by the +x direction. In Figure 7, a virtual parabola F1 of the reflective film 13 is shown by a dashed line, where the vertex of the reflective surface 13a in region C1 is in contact with the reflective surface 13a, and the curvature of the reflective surface 13a in region C1 is the same as that of the reflective surface 13a.

[0073] The general equation for a parabola whose vertex is at the origin in the xy-plane is y = ax 2 This is expressed as follows. The radius of curvature at the vertex (origin) of a parabola expressed by such a general formula is 1 / (2|a|).

[0074] As described above, the radius of curvature R of the reflective surface 13a and the radius of curvature of the virtual parabola F1 are the same. Therefore, considering that the radius of curvature R is a positive number, the equation representing the virtual parabola F1 shown in Figure 7 is y = x 2 This becomes (2R).

[0075] As mentioned above, the radius of curvature R in the first embodiment is substantially equivalent to half the inner diameter of the pipe body 11, given that the thickness of the reflective film 13 is very thin.

[0076] Furthermore, y=ax 2 The focal point of the parabola represented by this equation is located 1 / (4|a|) away from the vertex in the y-direction. In other words, the focal point of the virtual parabola F1 shown in Figure 7 is located R / 2 away in the y-direction from the point of tangency with the reflective surface 13a, which is the vertex.

[0077] A parabolic reflective surface reflects light emitted isotropically from a light source positioned at the focal point in a way that makes it parallel. In other words, in the configuration of the heating lamp 10 in the first embodiment, when the central axis 12c of the filament 12 is positioned at d=3.5mm (=R / 2), in the vicinity of region C1 of the reflective surface 13a shown in Figure 7, the reflective surface 13a acts like a pseudo-parabolic reflective surface, reflecting the light emitted from the filament 12 in a way that makes it roughly parallel. Furthermore, light reflected by the reflective surface 13a near region C2, which is far from region C1 and located in the ±x direction when viewed from the tube axis 11c, is not returned to the filament 12 side but is emitted to the outside of the tube 11.

[0078] Furthermore, when the central axis 12c of the filament 12 is positioned such that d > 3.5 mm (= R / 2), the light reflected in the region close to region C1 of the reflective surface 13a is less likely to become nearly parallel light. However, some of this light will propagate to the +y side region of the filament 12, as shown by light L1 in Figure 7. In other words, although the irradiation will no longer be nearly parallel reflected light, the illuminance distribution when viewed over the entire light-irradiated surface W1a of the object to be heated will be an illuminance distribution that exhibits sufficiently high homogeneity.

[0079] The above verification results are presumed to be due to the structure of the heating lamp 10 as described above.

[0080] Based on the above, the above configuration allows more light emitted from the filament 12, which is the light-emitting element, to be irradiated onto the object to be heated W1, and also allows for a more uniform illuminance distribution on the light-irradiated surface W1a of the object to be heated W1. Furthermore, since the light heating device 1 does not require a separate reflective member if it is equipped with a heating lamp 10, an increase in the overall size of the device is avoided.

[0081] [Second Embodiment] The configuration of the second embodiment of the optical heating device 1 of the present invention will be described, focusing on the differences from the first embodiment.

[0082] Figure 8 is a schematic diagram of the second embodiment of the optical heating device 1 as viewed in the Y direction, and Figure 9 is a schematic diagram of the optical heating device 1 of Figure 8 as viewed in the X direction. Figure 10 is a diagram of the heating lamp 10 mounted on the optical heating device 1 of Figure 8 as viewed in the X direction. As shown in Figure 10, the tube 11 comprises a first tube wall 11p that exhibits an arc shape when viewed in the X direction, which is along the tube axis 11c, and a second tube wall 11q that linearly connects the first end 11pa and the second end 11pb of the first tube wall 11p.

[0083] In the second embodiment, the tube axis 11c of the tube body 11 corresponds to the position of the center of gravity of the tube body 11 when viewed in the Y direction. Also, in Figure 10, the tube axis 11c of the tube body 11 and the central axis 12c of the filament 12 are approximately coincident, but the filament 12 may be misaligned with the tube axis 11c of the tube body 11 as long as it is arranged to satisfy at least equation (1) above.

[0084] As described above, the tube 11 can be easily manufactured, for example, by preparing a cylindrical tube, heating it until it becomes deformable, and then pressing a part of the tube wall against a flat surface. In the configuration shown in Figure 10, the thickness of the second tube wall 11q is formed to be thicker than the thickness of the first tube wall 11p, but the first tube wall 11p may be formed to be thicker, or the first tube wall 11p and the second tube wall 11q may be formed to be the same thickness.

[0085] In the second embodiment, the reflective film 13 is formed on the outer wall surface 11a of the tube body 11, extending from the first end 11pa to the second end 11pb of the first tube wall 11p. The center of curvature Cp of the reflective surface 13a is at a different position from the tube axis 11c, as shown in Figure 10. The distance d is the distance between the center of curvature Cp of the reflective surface 13a and the central axis 12c of the filament 12, similar to the first embodiment.

[0086] In the second embodiment, the heating lamp 10 has a reflective film 13 formed on the outer wall surface 11a of the tube 11, but similar to the heating lamp 10 in the first embodiment, the reflective film 13 may also be formed on the inner wall surface 11b of the tube 11.

[0087] With the above configuration, in a heating light source unit 4 equipped with multiple heating lamps 10, as shown in Figure 9, the light emitted from the filament 12 of heating lamp 10a is not irradiated onto the adjacent heating lamp 10b, but is reflected by the reflective film 13. In other words, most of the light emitted from the filament 12 is reflected in a different direction from the other heating lamps 10 by the reflective surface 13a of the heating lamp 10 on which the filament 12 is mounted. As a result, the mutual irradiation and heating of adjacent heating lamps 10 is suppressed. Therefore, a light heating device 1 equipped with a heating light source unit 4 having multiple heating lamps 10 with the above configuration achieves a longer lifespan and higher reliability.

[0088] Although the above-described configurations assume that the heating lamp 10 is a halogen lamp, the heating lamp 10 may also be a carbon heater, for example.

[0089] [Alternative Embodiment] The following describes other embodiments.

[0090] <1> Figure 11 is a view of the heating lamp 10 in the X direction in another embodiment of the light heating device 1. The first tube wall 11p of the tube body 11 does not have to be circular or semicircular as in the configurations described above, but may be formed to be longer than a semicircle and shorter than a circle in the circumferential direction, as shown in Figure 11. The tube body 11 of this shape can be easily manufactured in the same way as the tube body 11 in the second embodiment described above.

[0091] Furthermore, the reflective film 13 may be formed only on a portion of the outer wall surface 11a of the first pipe wall 11p.

[0092] With the above configuration, the shape of the tube 11 and the area in which the reflective film 13 is formed can be appropriately adjusted according to the shape and size of the object to be heated W1, as well as the configuration of the heating light source unit 4, to control the illuminance distribution on the light-irradiated surface W1a of the object to be heated W1.

[0093] <2> Figure 12 is a view of the heating lamp 10 in the Z direction in another embodiment of the optical heating device 1, and Figure 13 is a cross-sectional view AA of the heating lamp 10 in Figure 12. The heating lamp 10 may include a curved tubular body 11 and a filament 12, as shown in Figure 12.

[0094] In Figure 12, for illustrative purposes, the filament 12 is simply shown as a line, and when viewed from the Z direction, the tube axis 11c of the tube body 11 and the filament 12 overlap. Also, the reflective film 13 is not shown so that the inside of the tube body 11 can be seen.

[0095] In the case where the tube 11 and filament 12 have a curved structure, in this specification, "viewing in the direction along the tube axis" means viewing the cross-section when the tube axis 11c and the tangent Ta are cut at the point of contact Tp between the tube axis 11c and the tangent Ta by a plane perpendicular to the tangent Ta (the YZ plane in Figure 12), in the direction of the tangent Ta (the X direction), as shown in Figure 12.

[0096] The heating lamp 10 with the above configuration allows for light irradiation with a more uniform illuminance distribution over the circumferential direction compared to a heating lamp 10 that extends in a straight line, for example, when heating an object W1 that has a disc shape with a light irradiation surface W1a.

[0097] <3> The configuration of the optical heating device 1 described above is merely an example, and the present invention is not limited to the configurations shown in the figures. [Explanation of symbols]

[0098] 1 : Optical heating device 2: Chamber 2a: Processing room 3: Support member 3a: protrusion 4: Heating light source unit 10, 10a, 10b: Heating lamps 11: Body 11a: External wall surface 11b: Inner wall surface 11c: Tube shaft 11p: First pipe wall 11pa: First end 11pb: Second end 11q: Second pipe wall 12: Filament 12c: Central axis 13: Reflective film 13a: Reflective surface 14: Supporter 15: Pinch seal section 101 : Optical heating device 110: Heating lamp 111: Body 111a: External wall surface 111c: Tube shaft 112: Filament 112c: Central axis 113 : Reflective film 113a : Reflective surface L1,L2: light M1: Illuminance meter W1: Object to be heated W1a: Light irradiation surface

Claims

1. A pipe body having a pipe axis that extends in a straight or curved shape, and including a first pipe wall whose cross-section when cut by a plane perpendicular to the pipe axis is arc-shaped, A light-emitting element is placed inside the tube and extends along the axis of the tube, The first tube wall is provided with a reflective film that reflects light emitted from the light-emitting element, which is provided on at least a portion of the tube wall so as to extend along the tube axis, When viewed in the direction along the tube axis, R is the radius of curvature of the reflective surface of the reflective film that faces the light-emitting element, and d is the distance between the center of curvature of the reflective surface and the central axis of the light-emitting element. The light-emitting element is positioned within the tube at a location that satisfies the following equation (1): A heating lamp characterized in that the tube body has a second tube wall that linearly connects one end and the other end of the first tube wall, which has an arc shape when viewed in the direction along the tube axis. R / 2≦d<R (1)

2. The heating lamp according to claim 1, characterized in that the light-emitting element is positioned within the tube at a location that satisfies the following equation (2) when viewed in the direction along the tube axis. (R / 2)×1.1≦d≦(R / 2)×1.3 (2)

3. The heating lamp according to claim 1, characterized in that the reflective film is formed on the inner wall surface side of the first tube wall.

4. The heating lamp according to claim 1, characterized in that the reflective film is formed extending from one end to the other end of the first tube wall when viewed in a direction along the tube axis.

5. The heating lamp according to claim 1, characterized in that the second tube wall is formed to be thicker than the first tube wall.

6. The heating lamp according to claim 1, characterized in that the main material of the reflective film is at least one selected from the group consisting of silica (SiO2), alumina (Al2O3), titania (TiO2), and boron nitride (BN).

7. The heating lamp according to claim 1, characterized in that the main material of the reflective film is at least one metal selected from the group consisting of aluminum (Al), copper (Cu), gold (Au), and rhodium (Rh).

8. The heating lamp according to claim 1, characterized in that the light-emitting element is a filament, and the main material of the filament is at least one selected from the group consisting of graphite, carbon, tungsten, nichrome, platinum, molybdenum, and iron-chromium.

9. A heating light source unit characterized by comprising a plurality of heating lamps as described in any one of claims 1 to 8.

10. A chamber for containing the object to be heated, A light heating device comprising at least one heating lamp according to any one of claims 1 to 8, which emits light toward the object to be heated housed in the chamber.

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