Pedestal, heat treatment apparatus, and method for manufacturing pedestal

Abstract

The invention provides a technology capable of improving uniformity of in-plane temperature distribution of a substrate. The invention relates to a susceptor, a heat treatment apparatus, and a susceptor manufacturing method. A semiconductor wafer held on a susceptor is irradiated with light from below by a halogen lamp and preheated, and then the semiconductor wafer is irradiated with flash light from above by a flash lamp. In a holding plate (75) of the susceptor, a processing region (95) and a non-processing region (96) are provided in a mixed manner in a region facing a high-temperature region of the semiconductor wafer, said high-temperature region being a region at or above a predetermined temperature in a temperature distribution generated on the semiconductor wafer when irradiated with light. The machining region (95) and the non-machining region (96) have a circular ring shape alternately provided in a concentric circle shape. The processing area (95) is subjected to sand blasting, so that the processing area (95) becomes a rough surface, and the non-processing area (96) is not processed. As a result, the transmittance of the processing region is reduced, and the amount of light irradiated to the high-temperature region of the semiconductor wafer is reduced, thereby improving the uniformity of the in-plane temperature distribution of the semiconductor wafer (W).

Description

TECHNICAL FIELD

[0001] The present application relates to a susceptor supporting a substrate heated by light irradiation, a manufacturing method of the susceptor, and a heat treatment apparatus equipped with the susceptor. The substrate as a processing target includes, for example, a semiconductor wafer, a substrate for liquid crystal display devices, a substrate for FPD (flat panel display), a substrate for optical discs, a substrate for magnetic discs, or a substrate for solar cells, and the like. BACKGROUND

[0002] In the manufacturing process of semiconductor devices, flash lamp annealing (FLA) which heats a semiconductor wafer in an extremely short time is attracting attention. The flash lamp annealing is a kind of heat treatment technology which raises only the front surface of a semiconductor wafer in an extremely short time (several milliseconds or less) by irradiating a flash of light to the front surface of the semiconductor wafer using a xenon flash lamp (hereinafter, referred to as "flash lamp" means a xenon flash lamp).

[0003] The radiation spectrum distribution of the xenon flash lamp is in the ultraviolet region to the near infrared region, and the wavelength is shorter than that of the conventional halogen lamp, and is approximately coincident with the fundamental absorption band of a silicon semiconductor wafer. Therefore, when a flash of light is irradiated to a semiconductor wafer by the xenon flash lamp, the transmitted light is small, and the semiconductor wafer can be rapidly raised in temperature. In addition, it is found that if a flash of light is irradiated in an extremely short time of several milliseconds or less, only the vicinity of the front surface of the semiconductor wafer can be selectively raised in temperature.

[0004] This kind of flash lamp annealing is used for a process which needs to be heated in an extremely short time, and is typically used for activation of impurities implanted into a semiconductor wafer. If a flash of light is irradiated to the front surface of a semiconductor wafer in which impurities are implanted by an ion implantation method by a flash lamp, the front surface of the semiconductor wafer can be raised in temperature to an activation temperature in an extremely short time, and only impurity activation can be performed without diffusing the impurities to a deep portion.

[0005] As a heat treatment apparatus using this kind of xenon flash lamp, in Patent Documents 1 and 2, an apparatus is disclosed in which a flash lamp or the like pulse light emitting lamp is arranged on the front surface side of a semiconductor wafer, and a halogen lamp or the like continuous lighting lamp is arranged on the back surface side, and a desired heat treatment is performed by the combination thereof. In this kind of heat treatment apparatus, the semiconductor wafer is preheated to a certain temperature by the halogen lamp, and then the semiconductor wafer is raised in temperature to a desired processing temperature by pulse heating by the flash lamp. If preheating is performed by the halogen lamp, the following process advantage can be obtained: the semiconductor wafer can be raised in temperature to a relatively high preheating temperature in a short time.

[0006] [Patent Document]

[0007] [Patent Document]

[0008] [Patent Literature 1] Japanese Patent Application Laid-Open No. 2018-133424

[0009] [Patent Literature 2] Japanese Patent Application Laid-Open No. 2021-77660 SUMMARY

[0010] [Problems to be Solved by the Invention]

[0011] However, if the halogen lamp is provided in two stages of an upper stage and a lower stage as disclosed in Patent Literatures 1 and 2, the following undesirable situation occurs: the light amount of light irradiated to the vicinity of the center of the semiconductor wafer increases, resulting in a relatively low temperature of the peripheral portion of the semiconductor wafer at the time of preheating. In order to solve this uneven in-plane temperature distribution of the semiconductor wafer at the time of preheating, a cylindrical light shielding body formed of opaque quartz has been used conventionally (Patent Literature 1).

[0012] However, by providing the cylindrical light shielding body, although the temperature of the peripheral portion of the semiconductor wafer is relatively reduced, a new problem occurs in which the temperature of a region slightly inward of the peripheral portion of the semiconductor wafer is relatively high. Therefore, in Patent Literature 1, it is proposed to form a low-transmission region by cutting processing a part of the susceptor which opposes the high-temperature region occurring on the semiconductor wafer. In addition, in Patent Literature 2, surface roughening processing is performed on a part of the susceptor which opposes the high-temperature region of the semiconductor wafer.

[0013] However, even with these techniques, it is difficult to make the in-plane temperature distribution of the semiconductor wafer uniform enough at the time of light irradiation by the halogen lamp.

[0014] The present application was accomplished in view of the above-described problems, and aims to provide a technology capable of improving the uniformity of the in-plane temperature distribution of a substrate.

[0015] [Technical Means for Solving the Problems]

[0016] In order to solve the above-described problems, a first aspect of the present application is a susceptor which supports a substrate heated by light irradiation, comprising: a holding plate formed of quartz and being a flat plate; and a plurality of substrate support pins formed of quartz and vertically provided to the holding plate to support the substrate; and a processed region and a non-processed region are mixedly provided in a region of the holding plate which opposes a high-temperature region of the substrate, and the processed region is a rough surface, the high-temperature region of the substrate being a region which becomes a prescribed temperature or more in a temperature distribution of the substrate when light is irradiated to the substrate supported by the plurality of substrate support pins.

[0017] In addition, a second aspect is the susceptor according to the first aspect, in which the surface roughness of the rough surface of the processed region differs depending on the temperature in the temperature distribution.

[0018] Further, a third aspect is the susceptor according to the second aspect, wherein a surface roughness of a roughened surface of a processing region facing a region of relatively high temperature in the temperature distribution is greater than a surface roughness of a roughened surface of a processing region facing a region of relatively low temperature.

[0019] Further, a fourth aspect is the susceptor according to any one of the first to third aspects, wherein the processing region and the non-processing region have a shape of a circular ring alternately arranged in a concentric circular shape.

[0020] Further, a fifth aspect is a thermal processing apparatus that heats a substrate by irradiating light to the substrate, and includes: a chamber that houses the substrate; a susceptor according to any one of the first to fourth aspects, provided in the chamber to support the substrate; and a light source that irradiates light to the substrate.

[0021] Further, a sixth aspect is the thermal processing apparatus according to the fifth aspect, wherein the light source includes a continuous point light source that irradiates light from below the chamber to heat the substrate.

[0022] Further, a seventh aspect is the thermal processing apparatus according to the sixth aspect, wherein the light source further includes a flash light source that irradiates a flash of light to the substrate from above the chamber.

[0023] Further, an eighth aspect is a method of manufacturing a susceptor that supports a substrate heated by light irradiation, a processing region and a non-processing region are mixedly provided in a region of a holding plate facing a high temperature region of the substrate, and surface roughening processing is performed on the processing region, the high temperature region of the substrate being a region that becomes a prescribed temperature or more in a temperature distribution of the substrate when light is irradiated to the substrate supported by a plurality of substrate support pins erected in the holding plate formed in a flat plate shape by quartz.

[0024] Further, a ninth aspect is the method of manufacturing a susceptor according to the eighth aspect, wherein the processing region and the non-processing region have a shape of a circular ring alternately arranged in a concentric circular shape.

[0025] Further, a tenth aspect is the method of manufacturing a susceptor according to the eighth or ninth aspect, wherein the surface roughening processing is sandblasting processing.

[0026] Further, an eleventh aspect is the method of manufacturing a susceptor according to the tenth aspect, wherein a grit size of an abrasive used in the sandblasting processing is 1 80 or more and 320 or less.

[0027] Further, the 12th aspect is a manufacturing method of the susceptor according to the 11th aspect, wherein a grit number of an abrasive for the sandblasting process on the processing region facing the region with relatively high temperature in the temperature distribution is smaller than a grit number of an abrasive for the sandblasting process on the processing region facing the region with relatively low temperature.

[0028] [Effects of Invention]

[0029] According to the susceptor of the 1st to 4th aspects, since the processing region and the non-processing region are mixedly arranged in the region of the holding plate facing the high-temperature region of the substrate, and the processing region is a rough surface, the transmittance of the processing region is reduced, the light amount of light irradiated to the high-temperature region of the substrate is reduced, and thus the uniformity of the in-plane temperature distribution of the substrate can be improved.

[0030] Especially, according to the susceptor of the 3rd aspect, since the surface roughness of the rough surface of the processing region facing the region with relatively high temperature in the temperature distribution is larger than the surface roughness of the rough surface of the processing region facing the region with relatively low temperature, the uniformity of the in-plane temperature distribution of the substrate can be further improved.

[0031] According to the heat treatment apparatus of the 5th to 7th aspects, since the susceptor of the 1st to 4th aspects is provided, the uniformity of the in-plane temperature distribution of the substrate can be improved.

[0032] According to the manufacturing method of the susceptor of the 8th to 11th aspects, since the processing region and the non-processing region are mixedly arranged in the region of the holding plate facing the high-temperature region of the substrate, and the surface roughening process is performed on the processing region, the transmittance of the processing region is reduced, the light amount of light irradiated to the high-temperature region of the substrate is reduced, and thus the uniformity of the in-plane temperature distribution of the substrate can be improved.

[0033] Especially, according to the manufacturing method of the susceptor of the 12th aspect, since the grit number of the abrasive for the sandblasting process on the processing region facing the region with relatively high temperature in the temperature distribution is smaller than the grit number of the abrasive for the sandblasting process on the processing region facing the region with relatively low temperature, the uniformity of the in-plane temperature distribution of the substrate can be further improved. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 is a longitudinal sectional view showing the configuration of the heat treatment apparatus of the present application.

[0035] Figure 2 is a perspective view showing the overall appearance of the holding section.

[0036] Figure 3 is a plan view of the susceptor.

[0037] Figure 4is a sectional view of the base.

[0038] Figure 5 is a plan view of the transfer mechanism.

[0039] Figure 6 is a side view of the transfer mechanism.

[0040] Figure 7 is a plan view showing the arrangement of a plurality of halogen lamps.

[0041] Figure 8 is a view showing an example of temperature distribution in a wafer surface generated when a wafer is irradiated with light from halogen lamps while the wafer is held on a base on which no special processing has been performed.

[0042] Figure 9 is a plan view obtained by viewing the holding plate from below.

[0043] Figure 10 is a view obtained by enlarging the vicinity of the center of the lower surface of the holding plate.

[0044] Figure 11 is a view showing another example of a processed region and a non-processed region. DETAILED DESCRIPTION

[0045] Hereinafter, embodiments of the present application will be described in detail with reference to the drawings. Hereinafter, with respect to expressions indicating relative or absolute positional relationships (for example, "in a direction", "along a direction", "parallel", "orthogonal", "center", "concentric", "coaxial", and the like), unless otherwise specified, not only a strict positional relationship is indicated, but also a state in which a positional relationship is relatively shifted in terms of angle or distance within a range of tolerance or a range in which a function of the same degree can be obtained is indicated. In addition, with respect to expressions indicating an equal state (for example, "identical", "equal", "homogeneous", and the like), unless otherwise specified, not only a state in which a quantitative relationship is strictly equal is indicated, but also a state in which a difference exists within a range of tolerance or a range in which a function of the same degree can be obtained is indicated. In addition, with respect to expressions indicating a shape (for example, "circular shape", "quadrangular shape", "cylindrical shape", and the like), unless otherwise specified, not only a strict shape in geometry is indicated, but also a shape within a range in which a function of the same degree can be obtained, for example, a shape having a concave-convex or a chamfer, and the like, can be indicated. In addition, expressions such as "provided with", "furnished with", "equipped with", "including", "having", and the like, are not exclusive expressions indicating that only the mentioned component exists. In addition, an expression such as "at least one of A, B, and C" includes "only A", "only B", "only C", "any two of A, B, and C", and "A, B, and C all together".

[0046] Figure 1 is a longitudinal sectional view showing the configuration of a heat treatment apparatus 1 of the present application.Figure 1 The heat treatment apparatus 1 of the present embodiment is a flash lamp annealing apparatus that heats a semiconductor wafer W which is a circular plate-shaped substrate by flash irradiation. The size of the semiconductor wafer W as a processing target is not particularly limited, and is, for example, φ300 mm or φ450 mm (φ300 mm in the present embodiment). Further, the semiconductor wafer W is not particularly limited in the number of layers, and is, for example, a single layer or a plurality of layers. Figure 1 In each of the drawings described below and hereafter, the size or amount of each portion is exaggerated or simplified as necessary for the sake of convenience of understanding.

[0047] The heat treatment apparatus 1 includes a chamber 6 that houses the semiconductor wafer W, a flash heating section 5 that houses a plurality of flash lamps FL, and a halogen heating section 4 that houses a plurality of halogen lamps HL. The flash heating section 5 is provided on the upper side of the chamber 6, and the halogen heating section 4 is provided on the lower side. In addition, the heat treatment apparatus 1 includes a holding section 7 that holds the semiconductor wafer W in a horizontal posture inside the chamber 6, and a transfer mechanism 10 that performs handover of the semiconductor wafer W between the holding section 7 and the outside of the apparatus. Furthermore, the heat treatment apparatus 1 includes a control section 3 that controls each of the action mechanisms provided in the halogen heating section 4, the flash heating section 5, and the chamber 6 to perform heat treatment of the semiconductor wafer W.

[0048] The chamber 6 is configured by installing a chamber window made of quartz on the upper and lower sides of a cylindrical chamber side section 61. The chamber side section 61 has a substantially cylindrical shape with an upper side opening and a lower side opening, and the upper side opening is closed by an upper side chamber window 63, and the lower side opening is closed by a lower side chamber window 64. The upper side chamber window 63, which constitutes a top wall of the chamber 6, is a circular plate-shaped member formed of quartz, and functions as a quartz window that transmits flash light emitted from the flash heating section 5 into the chamber 6. In addition, the lower side chamber window 64, which constitutes a bottom plate section of the chamber 6, is also a circular plate-shaped member formed of quartz, and functions as a quartz window that transmits light from the halogen heating section 4 into the chamber 6.

[0049] In addition, a reflection ring 68 is installed on the upper portion of the inner side surface of the chamber side section 61, and a reflection ring 69 is installed on the lower portion. The reflection rings 68 and 69 are each formed in a circular ring shape. The upper reflection ring 68 is installed by being fitted from the upper side of the chamber side section 61. On the other hand, the lower reflection ring 69 is installed by being fitted from the lower side of the chamber side section 61 and being fixed with a screw that is not shown. That is, the reflection rings 68 and 69 are each detachably installed to the chamber side section 61. The inner space of the chamber 6, that is, the space surrounded by the upper side chamber window 63, the lower side chamber window 64, the chamber side section 61, and the reflection rings 68 and 69 is defined as a heat treatment space 65.

[0050] A recess 62 is formed in the inner wall surface of the chamber 6 by installing the reflection rings 68, 69 in the chamber side portion 61. That is, the recess 62 is formed by the central portion of the inner wall surface of the chamber side portion 61 in which the reflection rings 68, 69 are not installed, the lower end surface of the reflection ring 68, and the upper end surface of the reflection ring 69. The recess 62 is formed in a circular ring shape along the horizontal direction in the inner wall surface of the chamber 6, and surrounds the holding portion 7 that holds the semiconductor wafer W. The chamber side portion 61 and the reflection rings 68, 69 are formed of a metal material (for example, stainless steel) that is excellent in strength and heat resistance.

[0051] In addition, in the chamber side portion 61, a conveyance opening portion (furnace port) 66 through which the semiconductor wafer W is carried into and out of the chamber 6 is provided. The conveyance opening portion 66 is opened and closed by a gate valve 185. The conveyance opening portion 66 is in communication with the outer peripheral surface of the recess 62. Therefore, when the gate valve 185 opens the conveyance opening portion 66, the semiconductor wafer W can be carried into the heat treatment space 65 from the conveyance opening portion 66 through the recess 62, and the semiconductor wafer W can be carried out from the heat treatment space 65. In addition, when the gate valve 185 closes the conveyance opening portion 66, the heat treatment space 65 in the chamber 6 becomes a sealed space.

[0052] Further, in the chamber side portion 61, a through-hole 61a and a through-hole 61b are provided. The through-hole 61a is a cylindrical hole for guiding infrared light radiated from the upper surface of the semiconductor wafer W held on a susceptor 74 to the infrared sensor 29 of the upper radiation thermometer 25. On the other hand, the through-hole 61b is a cylindrical hole for guiding infrared light radiated from the lower surface of the semiconductor wafer W to the lower radiation thermometer 20. The through-holes 61a and 61b are provided obliquely with respect to the horizontal direction such that the axes of the through-holes intersect the main surface of the semiconductor wafer W held on the susceptor 74. A transparent window 26 that transmits infrared light in a wavelength region that can be measured by the upper radiation thermometer 25 is installed in the end portion of the through-hole 61a that faces the heat treatment space 65. In addition, a transparent window 21 that transmits infrared light in a wavelength region that can be measured by the lower radiation thermometer 20 is installed in the end portion of the through-hole 61b that faces the heat treatment space 65.

[0053] Further, on the upper portion of the inner wall of the chamber 6, a gas supply hole 81 is formed which supplies a processing gas to the heat treatment space 65. The gas supply hole 81 is formed at a position higher than the recess 62, and can be formed on the reflection ring 68. The gas supply hole 81 is connected to a gas supply pipe 83 via a buffer space 82 formed in a circular ring shape in the inner wall of the chamber 6. The gas supply pipe 83 is connected to a processing gas supply source 85. Further, a valve 84 is interposed in the path of the gas supply pipe 83. When the valve 84 is opened, the processing gas is supplied from the processing gas supply source 85 to the buffer space 82. The processing gas flowing into the buffer space 82 diffuses and flows in the buffer space 82 which has a smaller fluid resistance than the gas supply hole 81, and is supplied from the gas supply hole 81 to the heat treatment space 65. As the processing gas, for example, a non-reactive gas such as nitrogen (N2), a reactive gas such as hydrogen (H2) or ammonia (NH3), or a mixed gas obtained by mixing these gases (in this embodiment, nitrogen) can be used.

[0054] On the other hand, on the lower portion of the inner wall of the chamber 6, a gas exhaust hole 86 is formed which exhausts the gas in the heat treatment space 65. The gas exhaust hole 86 is formed at a position lower than the recess 62, and can be formed on the reflection ring 69. The gas exhaust hole 86 is connected to a gas exhaust pipe 88 via a buffer space 87 formed in a circular ring shape in the inner wall of the chamber 6. The gas exhaust pipe 88 is connected to the exhaust section 190. Further, a valve 89 is interposed in the path of the gas exhaust pipe 88. When the valve 89 is opened, the gas in the heat treatment space 65 is exhausted from the gas exhaust hole 86 via the buffer space 87 to the gas exhaust pipe 88. Further, the gas supply hole 81 and the gas exhaust hole 86 can be provided in plural along the circumference of the chamber 6, or can be formed in a slit shape. Further, the processing gas supply source 85 and the exhaust section 190 can be a mechanism provided in the heat treatment apparatus 1, or can be a factory facility provided with the heat treatment apparatus 1.

[0055] Further, the gas exhaust pipe 191 which exhausts the gas in the heat treatment space 65 is connected to the front end of the conveyance opening portion 66. The gas exhaust pipe 191 is connected to the exhaust section 190 via a valve 192. By opening the valve 192, the gas in the chamber 6 is exhausted via the conveyance opening portion 66.

[0056] Figure 2 is a perspective view showing the overall appearance of the holding section 7. The holding section 7 is composed of a base ring 71, a connecting portion 72, and a pedestal 74. The base ring 71, the connecting portion 72, and the pedestal 74 are all formed of quartz. That is, the holding section 7 is formed of quartz as a whole.

[0057] The base ring 71 is a quartz component with an arc shape formed by missing a portion of its circular ring shape. This missing portion is provided to prevent interference between the transfer arm 11 of the transfer mechanism 10 and the base ring 71. The base ring 71 is supported on the wall of the chamber 6 by being placed on the bottom surface of the recess 62 (see reference). Figure 1 On the upper surface of the base ring 71, a plurality of connecting parts 72 (four in this embodiment) are erected along the circumference of its annular shape. The connecting parts 72 are also quartz components and are fixed to the base ring 71 by welding.

[0058] The base 74 is supported by four connecting parts 72 provided on the base ring 71. Figure 3 This is a top view of base 74. Additionally, Figure 4 This is a cross-sectional view of the base 74. The base 74 includes a retaining plate 75, a guide ring 76, and a plurality of substrate support pins 77. The retaining plate 75 is a generally circular flat plate component formed of quartz. The diameter of the retaining plate 75 is larger than the diameter of the semiconductor wafer W. That is, the retaining plate 75 has a planar dimension larger than that of the semiconductor wafer W.

[0059] A guide ring 76 is provided at the periphery of the upper surface of the retaining plate 75. The guide ring 76 is a ring-shaped component with an inner diameter larger than the diameter of the semiconductor wafer W. For example, if the diameter of the semiconductor wafer W is φ300mm, the inner diameter of the guide ring 76 is φ320mm. The inner periphery of the guide ring 76 is designed as an inclined surface that widens upwards from the retaining plate 75. The guide ring 76 is formed of the same quartz as the retaining plate 75. The guide ring 76 can be fused to the upper surface of the retaining plate 75, or it can be fixed to the retaining plate 75 by a separately machined pin or the like. Alternatively, the retaining plate 75 and the guide ring 76 can be machined as a single component.

[0060] The area on the upper surface of the holding plate 75 that is further inward than the guide ring 76 is designated as the planar holding surface 75a for holding the semiconductor wafer W. Multiple substrate support pins 77 are vertically arranged on the holding surface 75a of the holding plate 75. In this embodiment, one substrate support pin 77 is vertically arranged every 30° along a circle on the holding surface 75a that is concentric with the outer circumference (inner circumference of the guide ring 76), for a total of 12 pins. The diameter of the circle containing the 12 substrate support pins 77 (the distance between opposing substrate support pins 77) is smaller than the diameter of the semiconductor wafer W. If the diameter of the semiconductor wafer W is φ300mm, then the diameter of the circle containing the 12 substrate support pins 77 is φ270mm to φ280mm (φ270mm in this embodiment). Each substrate support pin 77 is formed of quartz. The multiple substrate support pins 77 can be welded onto the upper surface of the holding plate 75 or integrally processed with the holding plate 75.

[0061] Back Figure 2The four connecting portions 72, which are erected on the base ring 71, are fixed to the periphery of the retaining plate 75 of the base 74 by welding. That is, the base 74 and the base ring 71 are fixedly connected by the connecting portions 72. The retaining portion 7 is installed in the chamber 6 by supporting the base ring 71 of this retaining portion 7 against the wall of the chamber 6. With the retaining portion 7 installed in the chamber 6, the retaining plate 75 of the base 74 is in a horizontal position (the normal is aligned with the vertical direction). That is, the retaining surface 75a of the retaining plate 75 is a horizontal surface.

[0062] The semiconductor wafer W, moved into chamber 6, is placed horizontally on the base 74 of the holding portion 7 installed in chamber 6. At this time, the semiconductor wafer W is supported by 12 substrate support pins 77 erected on the holding plate 75 and held on the base 74. More precisely, the upper ends of the 12 substrate support pins 77 contact the lower surface of the semiconductor wafer W, thereby supporting the semiconductor wafer W. The height of the 12 substrate support pins 77 (the distance from the upper end of the substrate support pin 77 to the holding surface 75a of the holding plate 75) is uniform, thus allowing the semiconductor wafer W to be supported in a horizontal position using the 12 substrate support pins 77.

[0063] Furthermore, the semiconductor wafer W is supported at predetermined intervals from the holding surface 75a of the holding plate 75 by a plurality of substrate support pins 77. The thickness of the guide ring 76 is greater than the height of the substrate support pins 77. Therefore, the guide ring 76 prevents the semiconductor wafer W, supported by the plurality of substrate support pins 77, from shifting in the horizontal direction.

[0064] In addition, such as Figure 2 and Figure 3 As shown, an opening 78 is formed vertically through the holding plate 75 of the base 74. The opening 78 is provided to allow the lower radiation thermometer 20 to receive emitted light (infrared light) from the lower surface of the semiconductor wafer W. Specifically, the lower radiation thermometer 20 receives light emitted from the lower surface of the semiconductor wafer W via the opening 78 and the transparent window 21 of the through-hole 61b mounted on the chamber side 61, thereby measuring the temperature of the semiconductor wafer W. Furthermore, four through-holes 79 are provided through the holding plate 75 of the base 74. These through-holes 79 are pierced by the lifting pin 12 of the transfer mechanism 10 described below for transferring the semiconductor wafer W. Additionally, in this embodiment, a portion of the lower surface of the holding plate 75 of the base 74 is roughened to reduce transmittance, which will be further described below.

[0065] Figure 5 This is a top view of the transfer mechanism 10. Additionally, Figure 6is a side view of the transfer mechanism 10. The transfer mechanism 10 is provided with two transfer arms 11. The transfer arms 11 are provided in a circular arc shape like a substantially circular ring-shaped recess 62. In each of the transfer arms 11, two lift pins 12 are vertically provided. The transfer arms 11 and the lift pins 12 are formed of quartz. Each of the transfer arms 11 is provided so as to be rotatable by a horizontal movement mechanism 13. The horizontal movement mechanism 13 moves the pair of transfer arms 11 horizontally between a transfer operation position (solid line position in Figure 5 ) at which the transfer of the semiconductor wafer W is performed with respect to the holding section 7 and a retreat position (double-dot chain line position in Figure 5 ) at which the pair of transfer arms 11 does not overlap the semiconductor wafer W held by the holding section 7 in plan view. As the horizontal movement mechanism 13, each of the transfer arms 11 can be individually rotated by independent motors, or a link mechanism can be used to rotate the pair of transfer arms 11 in conjunction by one motor.

[0066] In addition, the pair of transfer arms 11 is moved up and down together with the horizontal movement mechanism 13 by a lifting mechanism 14. When the lifting mechanism 14 raises the pair of transfer arms 11 at the transfer operation position, the total of four lift pins 12 are inserted through through-holes 79 (see Figure 2 , 3 ) provided through the base 74, and the upper ends of the lift pins 12 protrude from the upper surface of the base 74. On the other hand, when the lifting mechanism 14 lowers the pair of transfer arms 11 at the transfer operation position to withdraw the lift pins 12 from the through-holes 79, and the horizontal movement mechanism 13 moves the pair of transfer arms 11 apart, each of the transfer arms 11 is moved to the retreat position. The retreat position of the pair of transfer arms 11 is directly above the base ring 71 of the holding section 7. The base ring 71 is placed on the bottom surface of the recess 62, and thus the retreat position of the transfer arms 11 is inside the recess 62. Further, in the vicinity of the portion where the drive section (the horizontal movement mechanism 13 and the lifting mechanism 14) of the transfer mechanism 10 is provided, an exhaust mechanism, not shown, is also provided, which is configured to exhaust gas in the vicinity of the drive section of the transfer mechanism 10 to the outside of the chamber 6.

[0067] Returning to Figure 1 , the flash heating section 5 provided above the chamber 6 is configured to have, inside the housing 51, a light source including a plurality of (30 in this embodiment) xenon flash lamps FL, and a reflector 52 provided so as to cover the upper side of the light source. In addition, a light emission window 53 is installed in the bottom of the housing 51 of the flash heating section 5. The light emission window 53 constituting the bottom plate portion of the flash heating section 5 is a plate-shaped quartz window formed of quartz. By providing the flash heating section 5 above the chamber 6, the light emission window 53 is opposed to the upper side chamber window 63. The flash lamps FL irradiate flash from above the chamber 6 through the light emission window 53 and the upper side chamber window 63 to the heat treatment space 65.

[0068] The plurality of flash lamps FL are rod-shaped lamps each having an elongated cylindrical shape, and are arranged in a planar manner with their respective longitudinal directions parallel to each other along the main surface of the semiconductor wafer W held in the holding section 7 (i.e., along the horizontal direction). Thus, the plane formed by the arrangement of the flash lamps FL is also a horizontal plane. The region in which the plurality of flash lamps FL are arranged is larger than the planar size of the semiconductor wafer W.

[0069] The xenon flash lamp FL has a cylindrical glass tube (discharge tube) in which xenon gas is enclosed and both end portions of which are provided with an anode and a cathode connected to a capacitor, and a trigger electrode attached to the outer peripheral surface of the glass tube. Since xenon gas is an electrical insulator, no current flows in the glass tube even if the capacitor accumulates an electric charge in the normal state. However, when a high voltage is applied to the trigger electrode to cause dielectric breakdown, the electric charge stored in the capacitor momentarily flows into the glass tube, and at this time, atoms or molecules of the xenon gas are excited to emit light. This xenon flash lamp FL has the following characteristics: since the static electric energy stored in the capacitor is converted into an extremely short light pulse of 0.1 msec to 100 msec, it can emit extremely strong light compared to a light source such as the halogen lamp HL that is continuously lit. That is, the flash lamp FL is a pulse light lamp that emits light momentarily in an extremely short time of less than 1 sec. Furthermore, the light emission time of the flash lamp FL can be adjusted by the coil constant of a lamp power source that supplies electric power to the flash lamp FL.

[0070] In addition, a reflector 52 is provided above the plurality of flash lamps FL so as to cover the entirety of the plurality of flash lamps FL. The basic function of the reflector 52 is to reflect the flash light emitted from the plurality of flash lamps FL to the heat treatment space 65 side. The reflector 52 is formed of an aluminum alloy plate, and the surface (the surface facing the flash lamps FL) thereof is subjected to surface roughening processing by sandblasting.

[0071] The halogen heating section 4 provided below the chamber 6 has a plurality of (40 in this embodiment) halogen lamps HL built in the inside of the housing 41. The halogen heating section 4 is a light irradiation section that heats the semiconductor wafer W by light irradiation from below the chamber 6 to the heat treatment space 65 via the lower side chamber window 64 using the plurality of halogen lamps HL.

[0072] Figure 7 is a plan view showing the arrangement of the plurality of halogen lamps HL. The 40 halogen lamps HL are arranged in two sections, upper and lower. The upper section is provided with 20 halogen lamps HL near the holding section 7, and the lower section is also provided with 20 halogen lamps HL farther from the holding section 7 than the upper section. Each halogen lamp HL is a rod-shaped lamp having an elongated cylindrical shape. In both the upper and lower sections, the 20 halogen lamps HL are arranged with their respective longitudinal directions parallel to each other along the main surface of the semiconductor wafer W held in the holding section 7 (i.e., along the horizontal direction). Thus, in both the upper and lower sections, the plane formed by the arrangement of the halogen lamps HL is a horizontal plane.

[0073] In addition, such as Figure 7 As shown, both the upper and lower sections have a higher density of halogen lamps HL in the region facing the periphery compared to the region facing the center of the semiconductor wafer W held by the holding section 7. That is, both the upper and lower sections have a shorter spacing between the halogen lamps HL at the periphery compared to the central portion of the lamp arrangement. Therefore, more light can be applied to the periphery of the semiconductor wafer W, which is prone to temperature drop when heated by light from the halogen heating section 4.

[0074] Furthermore, the lamp group consisting of the upper halogen lamps HL and the lamp group consisting of the lower halogen lamps HL are arranged in a grid-like cross pattern. That is, a total of 40 halogen lamps HL are arranged such that the length direction of the 20 halogen lamps HL in the upper section is orthogonal to the length direction of the 20 halogen lamps HL in the lower section.

[0075] Halogen lamps (HL) are filament-based light sources. They emit light by incandescently heating a filament housed inside a glass tube. Inside the glass tube, a gas containing trace amounts of halogen elements (iodine, bromine, etc.) is introduced into a non-reactive gas such as nitrogen or argon. The introduction of halogen elements suppresses filament breakage and allows for a higher filament temperature. Therefore, halogen lamps (HL) have a longer lifespan and can continuously emit strong light compared to conventional incandescent bulbs. Specifically, halogen lamps (HL) are continuously lit lamps that emit light for at least one second. Furthermore, halogen lamps (HL) are rod-shaped, resulting in a long lifespan. By arranging halogen lamps (HL) horizontally, their radiation efficiency towards the semiconductor wafer W above them is excellent.

[0076] Additionally, a reflector 43 is provided below the two halogen lamps HL inside the housing 41 of the halogen heating section 4. Figure 1 Reflector 43 reflects the light emitted from the multiple halogen lamps HL to one side of the heat treatment space 65.

[0077] like Figure 1 As shown, the heat treatment apparatus 1 includes an upper radiation thermometer 25 and a lower radiation thermometer 20. The upper radiation thermometer 25 is positioned obliquely above the semiconductor wafer W held on the base 74, and receives infrared light emitted from the upper surface of the semiconductor wafer W to measure the temperature of the upper surface. The infrared sensor 29 of the upper radiation thermometer 25 includes an InSb (indium antimonide) optical element to cope with the rapid temperature change of the upper surface of the semiconductor wafer W at the moment of irradiation. On the other hand, the lower radiation thermometer 20 is positioned obliquely below the semiconductor wafer W held on the base 74, and receives infrared light emitted from the lower surface of the semiconductor wafer W to measure the temperature of the lower surface.

[0078] The control unit 3 controls the various operating mechanisms installed in the heat treatment apparatus 1. The hardware configuration of the control unit 3 is the same as that of a general computer. That is, the control unit 3 includes a CPU (circuit that performs various arithmetic operations), a ROM (Read-Only Memory) that stores the basic program, RAM (Read-Write-Free Memory) that stores various information, and a disk containing control software or data. The heat treatment apparatus 1 is processed by the CPU of the control unit 3 executing a predetermined processing program.

[0079] In this embodiment, a portion of the retaining plate 75 of the base 74 undergoes surface roughening. Specifically, the lower surface of the retaining plate 75 is sandblasted in a concentric circle near the center to create a roughened area.

[0080] Figure 8 This diagram illustrates an example of the temperature distribution within the wafer surface when a semiconductor wafer W is irradiated by halogen lamps HL while it is held on a substrate 74 without special processing. If, as in this embodiment, the 40 halogen lamps HL are arranged in upper and lower sections, light overlap occurs near the center of the semiconductor wafer W, resulting in a relatively increased amount of light irradiating this central area. Consequently, the central portion of the semiconductor wafer W is intensely heated compared to its periphery. Figure 8 As shown, a hot spot 99 appears near the center of the semiconductor wafer W. Furthermore, a hot spot is defined as a region with a relatively higher temperature compared to other regions within the surface of the semiconductor wafer W. The inventors, through experiments or simulations using a substrate 74 without special processing, have pre-defined such a hot spot... Figure 8 The in-plane temperature distribution is shown.

[0081] In this embodiment, based on, as Figure 8 The uneven in-plane temperature distribution shown causes the lower surface of the semiconductor wafer W held by the base 74 and the holding plate 75 to be sandblasted in a concentric circle shape near the center, making it a rough surface and thus reducing transmittance. Figure 9 This is a top view of the retaining plate 75 taken from below. Near the center of the lower surface of the retaining plate 75 (e.g., within a circle with a radius of 50 mm from the center), machined areas 95 and unmachined areas 96 are arranged in concentric circles, alternating between each other. The machined areas 95 are roughened by sandblasting.

[0082] Figure 10This is an enlarged view of the area near the center of the lower surface of the retaining plate 75. Near the center of the lower surface of the retaining plate 75, two outer processing areas 95a and three inner processing areas 95b are provided as processing areas 95. Unless otherwise specified, the outer processing areas 95a and the inner processing areas 95b are collectively referred to as processing areas 95. Each of the two outer processing areas 95a and the three inner processing areas 95b has a circular shape. Furthermore, the two outer processing areas 95a and the three inner processing areas 95b are formed as concentric circles with different diameters. The width of the outer processing area 95a is, for example, 3 mm. The width of the inner processing area 95b is, for example, 5 mm.

[0083] Furthermore, near the center of the lower surface of the retaining plate 75, the spacing between adjacent processing areas 95 is defined as non-processing areas 96; in other words, areas other than processing areas 95 are designated as non-processing areas 96. In this embodiment, a total of five processing areas 95 are provided, therefore five non-processing areas 96 are also provided. The innermost non-processing area 96 is circular, and the remaining four non-processing areas 96 are annular. The five non-processing areas 96 are formed in a concentric circle. The width of the non-processing area 96 adjacent to the inner side of the outer processing area 95a is, for example, 5 mm. The width of the non-processing area 96 adjacent to the inner side of the inner processing area 95b is 7 mm. The diameter of the innermost circular non-processing area 96 is, for example, 8 mm.

[0084] like Figure 10 As shown, in this embodiment, the annular processed area 95 and the non-processed area 96 are arranged in concentric circles, alternating in this manner. Therefore, it can be said that the processed area 95 and the non-processed area 96 are arranged with a uniform density around the center of the retaining plate 75, without any bias.

[0085] Five processing areas 95 are sandblasted to create rough surfaces. Sandblasting is a processing method in which abrasive (sand) is mixed with compressed air and blown towards the object. In this embodiment, the abrasive used in the sandblasting process has a grit size according to Japanese Industrial Standards (JIS), for example, 180 or higher and 320 or lower. The smaller the grit size, the coarser the abrasive (the larger the average particle size). Therefore, the smaller the grit size, the greater the surface roughness of the processed area 95, and the lower its transmittance.

[0086] In this embodiment, the two outer processing regions 95a are subjected to sandblasting processing using an abrasive having a grit size of No. 180. As a result, the surface roughness (arithmetic mean roughness (Ra)) of the outer processing regions 95a becomes 1.0 μm to 3.5 μm. On the other hand, the three inner processing regions 95b are subjected to sandblasting processing using an abrasive having a grit size of No. 320. As a result, the surface roughness of the inner processing regions 95b becomes 0.5 μm to 2.0 μm. Furthermore, the non-processing region 96 is not subjected to sandblasting processing.

[0087] In addition to the above-described configuration, in order to prevent excessive temperature rise of the halogen heating section 4, the flash heating section 5, and the chamber 6 due to heat energy generated by the halogen lamp HL and the flash lamp FL during heat treatment of the semiconductor wafer W, the heat treatment apparatus 1 is provided with various cooling configurations. For example, a water-cooling pipe (not shown) is provided on the wall of the chamber 6. In addition, the halogen heating section 4 and the flash heating section 5 are air-cooled configurations, and air flow is formed inside to discharge heat. In addition, air is supplied to the gap between the upper chamber window 63 and the lamp light emission window 53 to cool the flash heating section 5 and the upper chamber window 63.

[0088] Next, the processing operation in the heat treatment apparatus 1 will be described. Here, a typical heat treatment operation for a typical semiconductor wafer (product wafer) W as a product will be described. The processing sequence of the semiconductor wafer W described below is performed by controlling each operation mechanism of the heat treatment apparatus 1 by the control section 3.

[0089] First, the valve 84 for gas supply is opened, and at the same time, the valves 89, 192 for gas discharge are opened, so that gas supply and discharge to the chamber 6 is started. When the valve 84 is opened, nitrogen gas is supplied from the gas supply hole 81 to the heat treatment space 65. In addition, when the valve 89 is opened, the gas in the chamber 6 is discharged from the gas discharge hole 86. As a result, the nitrogen gas supplied from the upper portion of the heat treatment space 65 in the chamber 6 flows downward, and is discharged from the lower portion of the heat treatment space 65.

[0090] In addition, by opening the valve 192, the gas in the chamber 6 is also discharged from the conveyance opening 66. Furthermore, by the gas discharge mechanism not shown, the gas around the drive section of the transfer mechanism 10 is also discharged. Furthermore, when the semiconductor wafer W is subjected to heat treatment in the heat treatment apparatus 1, nitrogen gas is continuously supplied to the heat treatment space 65, and the supply amount thereof is appropriately changed according to the processing step.

[0091] Next, the gate valve 185 is opened to open the transfer opening portion 66, and a transfer robot outside the apparatus transfers a semiconductor wafer W as a processing target into the heat treatment space 65 in the chamber 6 via the transfer opening portion 66. At this time, gas outside the apparatus can be brought in with the semiconductor wafer W, but since nitrogen gas is continuously supplied to the chamber 6, the nitrogen gas flows out from the transfer opening portion 66, and the bringing in of such outside gas can be suppressed to a minimum.

[0092] The semiconductor wafer W brought in by the transfer robot enters and stops at a position directly above the holding portion 7. Then, the pair of transfer arms 11 of the transfer mechanism 10 moves horizontally from the retracted position to the transfer operation position and then rises, thereby causing the jacks 12 to pass through the through holes 79, protrude from the upper surface of the holding plate 75 of the susceptor 74, and receive the semiconductor wafer W. At this time, the jacks 12 rise to a position higher than the upper ends of the substrate support pins 77.

[0093] After the semiconductor wafer W is placed on the jacks 12, the transfer robot exits from the heat treatment space 65, and the gate valve 185 is closed to close the transfer opening portion 66. Then, by lowering the pair of transfer arms 11, the semiconductor wafer W is delivered from the transfer mechanism 10 to the susceptor 74 of the holding portion 7 and is held in a horizontal posture from below. The semiconductor wafer W is held by the susceptor 74 by being supported by the plurality of substrate support pins 77 standing on the holding plate 75. In addition, the semiconductor wafer W is held in the holding portion 7 with the front surface on which a pattern is formed as the upper surface. A prescribed gap is formed between the back surface (the main surface on the side opposite to the front surface) of the semiconductor wafer W supported by the plurality of substrate support pins 77 and the holding surface 75a of the holding plate 75. The pair of transfer arms 11 lowered below the susceptor 74 is retracted to the retracted position, i.e., the inside of the recess 62, by the horizontal movement mechanism 13.

[0094] After the semiconductor wafer W is held in a horizontal posture from below by the susceptor 74 of the holding portion 7 formed of quartz, the 40 halogen lamps HL of the halogen heating portion 4 are simultaneously turned on, and preheating (auxiliary heating) is started. Halogen light emitted from the halogen lamps HL passes through the lower chamber window 64 and the susceptor 74 formed of quartz and is irradiated to the lower surface of the semiconductor wafer W. The semiconductor wafer W is preheated and the temperature thereof is raised by receiving the light irradiation from the halogen lamps HL. In addition, the transfer arms 11 of the transfer mechanism 10 have been retracted to the inside of the recess 62, and thus do not interfere with the heating by the halogen lamps HL.

[0095] In the present embodiment, a processed region 95 of the lower surface of the holding plate 75 which opposes the vicinity of the center of the semiconductor wafer W which easily becomes high temperature is subjected to sandblasting processing and is made into a rough surface. Therefore, the transmittance of the processed region 95 is lower than that of other regions, the light quantity of light irradiated to the vicinity of the center of the semiconductor wafer W becomes small, and it is possible to suppress the temperature of the center of the semiconductor wafer W from becoming excessively high. Figure 8The hot spot 99 appears as shown. As a result, the uniformity of the in-plane temperature distribution of the semiconductor wafer W at the time of light irradiation by the halogen lamp HL can be improved.

[0096] When preheating is performed using the halogen lamp HL, the temperature of the semiconductor wafer W is measured by the lower radiation thermometer 20. That is, the lower radiation thermometer 20 receives infrared light radiated from the lower surface of the semiconductor wafer W held on the susceptor 74 via the opening portion 78 through the transparent window 21, thereby measuring the wafer temperature during temperature rise. The measured temperature of the semiconductor wafer W is transmitted to the control section 3. The control section 3 controls the output of the halogen lamp HL while monitoring whether the temperature of the semiconductor wafer W raised by light irradiation from the halogen lamp HL reaches the prescribed preheating temperature Tl. That is, the control section 3 performs feedback control of the output of the halogen lamp HL based on the measured value of the lower radiation thermometer 20 to make the temperature of the semiconductor wafer W the preheating temperature Tl. As such, the lower radiation thermometer 20 is a radiation thermometer for controlling the temperature of the semiconductor wafer W during preheating.

[0097] After the temperature of the semiconductor wafer W reaches the preheating temperature Tl, the control section 3 temporarily maintains the semiconductor wafer W at this preheating temperature Tl. Specifically, at the point in time when the temperature of the semiconductor wafer W measured by the lower radiation thermometer 20 reaches the preheating temperature Tl, the control section 3 adjusts the output of the halogen lamp HL to maintain the temperature of the semiconductor wafer W at approximately the preheating temperature Tl.

[0098] At the point in time when the temperature of the semiconductor wafer W reaches the preheating temperature Tl and a prescribed time elapses, the front surface of the semiconductor wafer W held on the susceptor 74 is subjected to flashing irradiation from the flash lamp FL of the flash heating section 5. At this time, a part of the flashing light radiated from the flash lamp FL directly enters the chamber 6, and another part of the flashing light is reflected by the reflector 52 to enter the chamber 6, and flashing heating of the semiconductor wafer W is performed by irradiation of these flashing lights.

[0099] Flashing heating is performed by flashing light irradiation from the flash lamp FL, and thus the front surface temperature of the semiconductor wafer W can be raised in a short time. That is, the flashing light irradiated from the flash lamp FL is extremely short and intense flashing light in which electrostatic energy stored in a capacitor in advance is converted into a light pulse of extremely short duration and the irradiation time is approximately 0.1 msec or more and 100 msec or less. Also, the front surface temperature of the semiconductor wafer W subjected to flashing heating by flashing light irradiation from the flash lamp FL rises to the processing temperature T2 in an instant and then rapidly decreases.

[0100] After the flash heating treatment ends, the halogen lamp HL is turned off after a prescribed time elapses. As a result, the semiconductor wafer W is rapidly cooled from the preheating temperature Tl. The temperature of the semiconductor wafer W during the cooling is measured by the lower radiation thermometer 20, and the measured result is transmitted to the control section 3. The control section 3 monitors whether or not the temperature of the semiconductor wafer W is cooled to a prescribed temperature based on the measured result of the lower radiation thermometer 20. Then, after the temperature of the semiconductor wafer W is cooled to below the prescribed temperature, the pair of transfer arms 11 of the transfer mechanism 10 is moved horizontally from the retracted position to the transfer operation position again and then raised, so that the jacks 12 are projected from the upper surface of the pedestal 74 to receive the heat-treated semiconductor wafer W from the pedestal 74. Next, the conveyance opening portion 66 closed by the gate valve 185 is opened, and the semiconductor wafer W placed on the jacks 12 is carried out from the chamber 6 by a conveyance robot outside the apparatus, and the heating treatment of the semiconductor wafer W is completed.

[0101] In the present embodiment, the machined region 95 and the non-machined region 96 are mixedly provided on the lower surface of the region of the holding plate 75 that opposes the high-temperature region (hot spot 99) of the semiconductor wafer W, which is a region that becomes a prescribed temperature or higher in the temperature distribution generated in the semiconductor wafer W when light is irradiated from the halogen lamp HL to the semiconductor wafer W supported by the plurality of substrate support pins 77 of the pedestal 74. Further, the machined region 95 is made into a rough surface by sandblasting processing of the machined region 95. By making the machined region 95 into a rough surface, the transmittance of the machined region 95 is reduced, the light quantity of the light irradiated to the high-temperature region of the semiconductor wafer W is reduced, and the appearance of the hot spot 99 can be suppressed, so that the uniformity of the in-plane temperature distribution of the semiconductor wafer W can be improved.

[0102] Here, even if the non-machined region 96 is not provided, and the entire surface of the region of the holding plate 75 that opposes the high-temperature region of the semiconductor wafer W is made rough by sandblasting processing, the light quantity of the light that reaches the high-temperature region of the semiconductor wafer W can be reduced. However, in this case, the light quantity of the light that reaches the high-temperature region of the semiconductor wafer W can be excessively reduced, and the high-temperature region can become a low-temperature region (cold spot) that is relatively low in temperature compared to the surroundings. As a result, the uniformity of the in-plane temperature distribution of the semiconductor wafer W cannot be obtained (becomes a non-uniform state in which the high-temperature region and the low-temperature region are reversed).

[0103] Therefore, in this embodiment, a processed area 95 and a non-processed area 96 are mixedly disposed on the lower surface of the holding plate 75, in the region facing the high-temperature region of the semiconductor wafer W. The processed area 95 is roughened by sandblasting, thus reducing its transmittance. On the other hand, the non-processed area 96 remains smooth without processing, so its transmittance is not reduced. As a result, the amount of light irradiating the high-temperature region of the semiconductor wafer W can be appropriately reduced, suppressing the occurrence of hot spots 99 and cold spots, while simultaneously improving the uniformity of the in-plane temperature distribution of the semiconductor wafer W. Furthermore, since the amount of light is adjusted by processing the holding plate 75, the uniformity of the in-plane temperature distribution of the semiconductor wafer W can be improved without increasing the number of components.

[0104] The embodiments of the present invention have been described above, but the present invention can be modified in various ways other than those described without departing from its spirit. For example, in the described embodiment, the annular processed area 95 and the unprocessed area 96 are arranged alternately in a concentric circle, but it is not limited to this, as long as the processed area 95 and the unprocessed area 96 are mixed in the region of the holding plate 75 facing the high-temperature region of the semiconductor wafer W. For example, if the high-temperature region appearing on the semiconductor wafer W is elliptical, then it can also be like... Figure 11 That's how you set up the processing area 95 and the non-processing area 96. Figure 11 In the example shown, on the lower surface of the holding plate 75, in an elliptical region facing the high-temperature region appearing on the semiconductor wafer W, processed regions 95 and unprocessed regions 96 are alternately arranged in a stripe pattern. That is, strip-shaped processed regions 95 and unprocessed regions 96 are alternately arranged. Similar to the embodiment described above, the processed regions 95 are roughened by sandblasting, and the unprocessed regions 96 are not processed. Even so, similar to the embodiment described above, the amount of light irradiating the high-temperature region of the semiconductor wafer W can be appropriately reduced, thereby suppressing the occurrence of hot spots 99 and cold spots, and improving the uniformity of the in-plane temperature distribution of the semiconductor wafer W.

[0105] Alternatively, the processed area 95 and the unprocessed area 96 can be arranged alternately in a checkerboard pattern, for example. In short, it is acceptable to mix the processed area 95 and the unprocessed area 96 in the area of ​​the holding plate 75 opposite to the high-temperature area generated on the semiconductor wafer W. In this case, it is preferable to arrange the processed area 95 and the unprocessed area 96 with a uniform density without bias.

[0106] In addition, in the embodiment, the surface roughness of the outer processing region 95a and the inner processing region 95b is made different, and the surface roughness of the processing region 95 is set to two levels, but it is not limited thereto, and the surface roughness of the processing region 95 can be made to be three or more different levels. That is, the surface roughness of each of the plurality of processing regions 95 can be a different value in the range of 0.5 μm or more and 3.5 μm or less.

[0107] In the case where the surface roughness of each of the plurality of processing regions 95 is set to a different value, it is preferable that the surface roughness of the rough surface of the processing region 95 facing a region where the temperature is relatively high in the temperature distribution generated in the semiconductor wafer W be greater than the surface roughness of the rough surface of the processing region 95 facing a region where the temperature is relatively low. That is, the grit number of the abrasive for the sandblasting processing of the processing region 95 facing a region where the temperature is relatively high in the in-plane temperature distribution generated in the semiconductor wafer W is made smaller than the grit number of the abrasive for the sandblasting processing of the processing region 95 facing a region where the temperature is relatively low. For example, the temperature of the semiconductor wafer W can be relatively high above the position where the halogen lamp HL of the upper stage and the halogen lamp HL of the lower stage cross, and in this case, it is only necessary that the surface roughness of the rough surface of the processing region 95 above the cross position be relatively large. Thereby, the light quantity of the light radiated to the region where the temperature is higher in the in-plane temperature distribution generated in the semiconductor wafer W is reduced more greatly, and it is possible to further improve the uniformity of the in-plane temperature distribution of the semiconductor wafer W.

[0108] In addition, in the embodiment, the processing region 95 and the non-processing region 96 are set based on the temperature distribution generated in the semiconductor wafer W when the light is radiated by the halogen lamp HL, but instead, the processing region 95 and the non-processing region 96 can be set based on the final temperature distribution generated in the semiconductor wafer W when the flash is radiated to the pre-heated semiconductor wafer W by the flash lamp FL.

[0109] In addition, in the embodiment, the sandblasting processing is performed as a method of making the processing region 95 a rough surface, but it is not limited thereto, and other chemical or physical methods can be employed. For example, the processing region 95 can be made a rough surface by etching using a prescribed liquid. Alternatively, the processing region 95 can be made a rough surface by lapping processing.

[0110] In addition, in the embodiment, the flash heating section 5 is provided with 30 flash lamps FL, but it is not limited thereto, and the number of the flash lamps FL can be set to an arbitrary number. In addition, the flash lamp FL is not limited to a xenon flash lamp, and can be a krypton flash lamp. In addition, the number of the halogen lamps HL provided in the halogen heating section 4 is not limited to 40, and can be set to an arbitrary number.

[0111] In addition, in the embodiment, the filament-type halogen lamp HL is used as the continuous lighting lamp for the preheating of the semiconductor wafer W, but the present application is not limited to this, and a discharge-type arc lamp (for example, a xenon arc lamp) or an LED lamp can be used instead of the halogen lamp HL as the continuous lighting lamp for the preheating.

[0112] [Explanation of symbols]

[0113] 1: heat treatment apparatus

[0114] 3: control unit

[0115] 4: halogen heating unit

[0116] 5: flash heating unit

[0117] 6: chamber

[0118] 7: holding unit

[0119] 10: transfer mechanism

[0120] 20: lower radiation thermometer

[0121] 25: upper radiation thermometer

[0122] 63: upper chamber window

[0123] 64: lower chamber window

[0124] 65: heat treatment space

[0125] 74: susceptor

[0126] 75: holding plate

[0127] 77: substrate support pin

[0128] 95: processing area

[0129] 96: non-processing area

[0130] FL: flash lamp

[0131] HL: halogen lamp

[0132] W: semiconductor wafer

Claims

1. A base supporting a substrate heated by light irradiation, comprising: The retaining plate is formed of quartz and is flat; and Multiple substrate support pins, formed of quartz, are erected on the retaining plate to support the substrate; and Processed and unprocessed areas are mixed in the area of ​​the holding plate opposite to the high-temperature area of ​​the substrate, and the processed area is rough. The high-temperature area of ​​the substrate is the area in the temperature distribution generated by the substrate when light is irradiated onto the substrate supported by the plurality of substrate support pins, which is above a specified temperature.

2. The base according to claim 1, wherein The surface roughness of the rough surface in the processing area varies depending on the temperature in the temperature distribution.

3. The base according to claim 2, wherein The surface roughness of the rough surface of the processing area opposite to the relatively high temperature region in the temperature distribution is greater than the surface roughness of the rough surface of the processing area opposite to the relatively low temperature region.

4. The base according to claim 1, wherein The processing area and the non-processing area have a ring shape that is arranged in concentric circles alternately.

5. A heat treatment apparatus for heating a substrate by irradiating it with light, and comprising: A chamber that houses the substrate; The base according to any one of claims 1 to 4 is disposed within the cavity to support the substrate; and A light source illuminates the substrate.

6. The heat treatment apparatus according to claim 5, wherein The light source comprises a continuously lit lamp that illuminates the substrate from below the chamber.

7. The heat treatment apparatus according to claim 6, wherein The light source also includes a flash lamp that illuminates the substrate from above the chamber.

8. A method for manufacturing a base, the base supporting a substrate heated by light irradiation, The method for manufacturing the base is to mix and set a processing area and a non-processing area in the area of ​​the holding plate opposite to the high temperature area of ​​the substrate, and to roughen the surface of the processing area. The high temperature area of ​​the substrate is the area in the temperature distribution generated by the substrate when light is irradiated onto the substrate supported by multiple substrate support pins, which is above a specified temperature. The multiple substrate support pins are erected on the holding plate, which is a flat plate formed of quartz.

9. The method for manufacturing the base according to claim 8, wherein... The processing area and the non-processing area have a ring shape that is arranged in concentric circles alternately.

10. The method for manufacturing the base according to claim 8, wherein... The surface roughening process is sandblasting.

11. The method for manufacturing the base according to claim 10, wherein... The abrasive used in the sandblasting process has a particle size of 180 or higher and 320 or lower.

12. The method for manufacturing the base according to claim 11, wherein... The particle size of the abrasive used for sandblasting is smaller than that used for sandblasting in areas opposite to the relatively high-temperature regions of the temperature distribution.

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