Susceptor, heat treatment device and method of manufacturing susceptor

Abstract

To provide a technique capable of improving uniformity of in-plane temperature distribution of a wafer.SOLUTION: After preheating is performed by irradiating a semiconductor wafer held by a susceptor with light from a lower side by a halogen lamp, the semiconductor wafer is irradiated with flash light from an upper side by a flash lamp. A processing region 95 of a bottom face of a holding plate 75 which is positioned between adjacent wafer support pins 77 in a plurality of wafer support pins 77 erected on the holding plate 75 of the susceptor is made into a rough surface by applying sand blasting thereto. The processing region 95 is opposed to a hot spot which appears when the semiconductor wafer held by the susceptor is irradiated with light. The quantity of light toward the hot spot in the light irradiation from the halogen lamp is reduced by the processing region 95 which is made into the rough surface. Therefore, a temperature of the hot spot is reduced and uniformity of in-plane temperature distribution of the semiconductor wafer can be improved.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to a susceptor for supporting a substrate heated by light irradiation, a method for manufacturing the susceptor, and a heat treatment apparatus equipped with the susceptor. The substrate to be treated includes, for example, a semiconductor wafer, a substrate for a liquid crystal display device, a substrate for a flat panel display (FPD), a substrate for an optical disk, a substrate for a magnetic disk, or a substrate for a solar cell. [Background technology]

[0002] Flash lamp annealing (FLA), which heats semiconductor wafers in an extremely short time, is attracting attention in the semiconductor device manufacturing process.Flash lamp annealing is a heat treatment technology that uses a xenon flash lamp (hereinafter, simply referred to as "flash lamp" means a xenon flash lamp) to irradiate the surface of a semiconductor wafer with flash light, thereby raising the temperature of only the surface of the semiconductor wafer in an extremely short time (a few milliseconds or less).

[0003] The spectral distribution of radiation from a xenon flash lamp is in the ultraviolet to near-infrared range, with a shorter wavelength than conventional halogen lamps and a wavelength that roughly matches the fundamental absorption band of silicon semiconductor wafers. Therefore, when a semiconductor wafer is irradiated with flash light from a xenon flash lamp, little light is transmitted, making it possible to rapidly heat the semiconductor wafer. It has also been found that if the flash light is irradiated for an extremely short period of time, less than a few milliseconds, it is possible to selectively heat only the area near the surface of the semiconductor wafer.

[0004] Flash lamp annealing is used in processes that require heating for an extremely short period of time, such as activating impurities implanted in a semiconductor wafer. By irradiating the surface of a semiconductor wafer into which impurities have been implanted by ion implantation with a flash light from a flash lamp, the surface of the semiconductor wafer can be heated to the activation temperature in an extremely short period of time, allowing only the impurities to be activated without diffusing them deeply.

[0005] Patent Documents 1 and 2 disclose heat treatment apparatuses using such xenon flash lamps, in which pulsed light-emitting lamps such as flash lamps are arranged on the front side of a semiconductor wafer and continuously lit lamps such as halogen lamps are arranged on the back side, and the desired heat treatment is performed by combining these. In such heat treatment apparatuses, the semiconductor wafer is preheated to a certain temperature using the halogen lamp, and then the temperature is raised to the desired treatment temperature using pulsed heating from the flash lamp. Preheating using a halogen lamp has the process advantage of being able to heat the semiconductor wafer to a relatively high preheat temperature in a short period of time. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2018-133424 [Patent Document 2] Patent Publication No. 2021-77660 Summary of the Invention [Problem to be solved by the invention]

[0007] However, as disclosed in Patent Documents 1 and 2, when halogen lamps are arranged in two stages, upper and lower, the amount of light irradiated toward the center of the semiconductor wafer increases, causing a problem in that the temperature of the peripheral edge of the semiconductor wafer becomes relatively low during preheating.To resolve this unevenness in the in-plane temperature distribution that occurs on the semiconductor wafer during preheating, cylindrical louvers made of opaque quartz have traditionally been used (Patent Document 1).

[0008] However, although the provision of cylindrical louvers eliminates the relative temperature drop at the peripheral edge of the semiconductor wafer, a new problem arises in that the area slightly inside the peripheral edge of the semiconductor wafer becomes relatively hot. For this reason, Patent Document 1 proposes forming a low-transmittance area by machining a portion of the susceptor facing the high-temperature area on the semiconductor wafer. Furthermore, Patent Document 2 discloses roughening a portion of the susceptor facing the high-temperature area on the semiconductor wafer.

[0009] However, even with these techniques, it remains difficult to achieve a sufficiently uniform temperature distribution within the surface of a semiconductor wafer when irradiated with light from a halogen lamp.

[0010] The present invention has been made in view of the above-mentioned problems, and has an object to provide a technique that can improve the uniformity of the temperature distribution within the surface of a substrate. [Means for solving the problem]

[0011] In order to solve the above problem, a first aspect of the present invention is a susceptor that supports a substrate heated by light irradiation, comprising a flat holding plate made of quartz, and a plurality of substrate support pins that are also made of quartz and are erected on the holding plate to support the substrate, and some or all of a plurality of processing areas of the holding plate that are located between adjacent ones of the plurality of substrate support pins are roughened.

[0012] In a second aspect, in the susceptor according to the first aspect, the plurality of substrate support pins are arranged at equal intervals on the same circumference, and the plurality of processing regions are provided along the circumference.

[0013] In addition, a third aspect is the susceptor according to the first or second aspect, wherein each of the plurality of processing regions is oval in shape.

[0014] In a fourth aspect, in the susceptor according to the third aspect, the center of gravity of the oval shape coincides with a midpoint along the circumference of adjacent substrate support pins that sandwich the processing region of the oval shape.

[0015] In addition, a fifth aspect is the susceptor according to the first or second aspect, wherein each of the plurality of processing regions has an oval shape or an elongated hole shape.

[0016] A sixth aspect is a susceptor according to any one of the first to fifth aspects, wherein the rough surface has a surface roughness of 0.2 μm or more and 2.0 μm or less.

[0017] In addition, in a seventh aspect, in the susceptor according to the sixth aspect, the surface roughness of the rough surface of the processing area of ​​the holding plate facing the area where the temperature is relatively high in the temperature distribution that occurs in the substrate when light is irradiated onto the substrate supported by the plurality of substrate support pins is made larger than the surface roughness of the rough surface of the processing area of ​​the holding plate facing the area where the temperature is relatively low.

[0018] In addition, an eighth aspect is a heat treatment apparatus that heats a substrate by irradiating the substrate with light, the heat treatment apparatus comprising: a chamber that accommodates the substrate; a susceptor according to any one of the first to seventh aspects that is provided in the chamber and supports the substrate; and a continuously lit lamp that irradiates light from below the chamber to heat the substrate.

[0019] In addition, a ninth aspect is the heat treatment apparatus according to the eighth aspect, further comprising a light blocking member disposed between the susceptor and the continuously lit lamp.

[0020] In addition, a tenth aspect is the heat treatment apparatus according to the eighth or ninth aspect, further comprising a flash lamp that irradiates the substrate with a flash of light from above the chamber.

[0021] In addition, an eleventh aspect is a method for manufacturing a susceptor that supports a substrate heated by light irradiation, in which a roughening process is performed on part or all of multiple processing areas of a flat holding plate made of quartz that are located between adjacent substrate support pins among multiple substrate support pins that are erected on the holding plate.

[0022] In addition, a twelfth aspect is the method for manufacturing a susceptor according to the eleventh aspect, wherein the plurality of substrate support pins are arranged at equal intervals on the same circumference, and the plurality of processing regions are provided along the circumference.

[0023] A thirteenth aspect is the method for manufacturing a susceptor according to the eleventh or twelfth aspect, wherein each of the plurality of processing regions has an oval shape.

[0024] In addition, a fourteenth aspect is a method for manufacturing a susceptor according to the thirteenth aspect, wherein the center of gravity of the oval shape coincides with the midpoint along the circumference of adjacent substrate support pins that sandwich the processing area of ​​the oval shape.

[0025] In a fifteenth aspect, in the method for manufacturing a susceptor according to the eleventh or twelfth aspect, each of the plurality of processing regions has an oval shape or an elongated hole shape.

[0026] In a sixteenth aspect, in the method for manufacturing a susceptor according to any one of the eleventh to fifteenth aspects, the surface roughening process is sandblasting.

[0027] In a seventeenth aspect, in the method for manufacturing a susceptor according to the sixteenth aspect, the grain size of the abrasive used in the sandblasting is no less than 240 and no more than 800.

[0028] In an 18th aspect, in the method for manufacturing a susceptor according to the 17th aspect, the grain size of the abrasive used in the sandblasting process performed on the processing area of ​​the holding plate facing the area where the temperature is relatively high in the temperature distribution that occurs in the substrate when light is irradiated onto the substrate supported by the plurality of substrate support pins is made smaller than the grain size of the abrasive used in the sandblasting process performed on the processing area of ​​the holding plate facing the area where the temperature is relatively low. [Effects of the Invention]

[0029] According to the susceptors of the first to seventh aspects, some or all of the multiple processing areas of the holding plate located between adjacent substrate support pins among the multiple substrate support pins are roughened, thereby reducing the amount of light reaching the high-temperature area of ​​the substrate and improving the uniformity of the in-plane temperature distribution of the substrate.

[0030] In particular, with the susceptor according to the seventh aspect, the surface roughness of the rough surface of the processing area facing the area of ​​the substrate where the temperature is relatively high is made larger than the surface roughness of the rough surface of the processing area facing the area where the temperature is relatively low, thereby further improving the uniformity of the temperature distribution within the surface of the substrate.

[0031] According to the heat treatment apparatuses of the eighth to tenth aspects, since they include the susceptors of the first to seventh aspects, it is possible to improve the uniformity of the temperature distribution within the surface of the substrate.

[0032] According to the susceptor manufacturing methods of the 11th to 18th aspects, roughening is performed on some or all of the multiple processing areas of the holding plate located between adjacent substrate support pins among multiple substrate support pins erected on a flat holding plate made of quartz, thereby reducing the amount of light reaching the high-temperature area of ​​the substrate and improving the uniformity of the temperature distribution within the surface of the substrate.

[0033] In particular, according to the susceptor manufacturing method of the 18th aspect, the particle size of the abrasive used in the sandblasting process performed on the processing area facing the area of ​​the substrate where the temperature is relatively high is made smaller than the particle size of the abrasive used in the sandblasting process performed on the processing area facing the area where the temperature is relatively low, thereby further improving the uniformity of the temperature distribution within the surface of the substrate. [Brief explanation of the drawings]

[0034] [Figure 1] 1 is a vertical cross-sectional view showing the configuration of a heat treatment apparatus according to the present invention. [Figure 2] FIG. 2 is a perspective view showing the overall appearance of the holding portion. [Figure 3] FIG. [Figure 4] FIG. 2 is a cross-sectional view of a susceptor. [Figure 5] FIG. [Figure 6] FIG. [Figure 7] FIG. 2 is a plan view showing the arrangement of a plurality of halogen lamps. [Figure 8] 1 is a diagram showing an example of the temperature distribution occurring within the wafer surface when a semiconductor wafer W is held on a susceptor that has not been subjected to any particular processing and is irradiated with light from a halogen lamp. [Figure 9] FIG. 2 is a plan view of the holding plate as viewed from below. [Figure 10] FIG. 1 is an enlarged view of the vicinity of one processed region. [Figure 11] 10A and 10B are diagrams illustrating other examples of the shape of the processing region. [Figure 12] 10A and 10B are diagrams illustrating other examples of the shape of the processing region. DETAILED DESCRIPTION OF THE INVENTION

[0035] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Hereinafter, expressions indicating relative or absolute positional relationships (e.g., "in one direction," "along one direction," "parallel," "orthogonal," "center," "concentric," "coaxial," etc.) not only strictly represent the positional relationship but also represent a state of relative angular or distance displacement within a tolerance or a range that provides equivalent functionality, unless otherwise specified. Furthermore, expressions indicating an equal state (e.g., "identical," "equal," "homogeneous," etc.) not only represent a state of strict quantitative equality but also represent a state of difference that provides a tolerance or equivalent functionality, unless otherwise specified. Furthermore, expressions indicating a shape (e.g., "circular," "square," "cylindrical," etc.) not only represent a geometrically strict shape but also represent a shape within a range that provides equivalent functionality, such as irregularities or chamfers, unless otherwise specified. Furthermore, expressions such as "comprise," "comprise," "include," "have," etc., regarding components, are not exclusive expressions that exclude the presence of other components. Furthermore, the expression "at least one of A, B, and C" includes "A only," "B only," "C only," "any two of A, B, and C," and "all of A, B, and C."

[0036] FIG. 1 is a vertical cross-sectional view showing the configuration of a heat treatment apparatus 1 according to the present invention. The heat treatment apparatus 1 in FIG. 1 is a flash lamp annealing apparatus that heats a disk-shaped semiconductor wafer W as a substrate by irradiating the semiconductor wafer W with flash light. The size of the semiconductor wafer W to be treated is not particularly limited, but is, for example, φ300 mm or φ450 mm (φ300 mm in this embodiment). Note that in FIG. 1 and the subsequent figures, the dimensions and number of various parts are exaggerated or simplified as necessary for ease of understanding.

[0037] Heat treatment apparatus 1 includes a chamber 6 that accommodates a semiconductor wafer W, a flash heating unit 5 that incorporates multiple flash lamps FL, and a halogen heating unit 4 that incorporates multiple halogen lamps HL. The flash heating unit 5 is provided above chamber 6, and the halogen heating unit 4 is provided below. Heat treatment apparatus 1 also includes, inside chamber 6, a holder 7 that holds the semiconductor wafer W in a horizontal position, and a transfer mechanism 10 that transfers the semiconductor wafer W between the holder 7 and the outside of the apparatus. Heat treatment apparatus 1 also includes a control unit 3 that controls the operating mechanisms provided in the halogen heating unit 4, flash heating unit 5, and chamber 6 to perform heat treatment on the semiconductor wafer W.

[0038] The chamber 6 is constructed by attaching quartz chamber windows to the top and bottom of a cylindrical chamber side portion 61. The chamber side portion 61 has a roughly cylindrical shape with openings at the top and bottom, with an upper chamber window 63 attached to and closing the upper opening, and a lower chamber window 64 attached to and closing the lower opening. The upper chamber window 63, which forms the ceiling of the chamber 6, is a disc-shaped member made of quartz and functions as a quartz window that transmits the flash light emitted from the flash heating unit 5 into the chamber 6. The lower chamber window 64, which forms the floor of the chamber 6, is also a disc-shaped member made of quartz and functions as a quartz window that transmits the light from the halogen heating unit 4 into the chamber 6.

[0039] Furthermore, a reflective ring 68 is attached to the upper part of the inner wall surface of the chamber side 61, and a reflective ring 69 is attached to the lower part. Both reflective rings 68, 69 are formed in an annular shape. The upper reflective ring 68 is attached by fitting it from the upper side of the chamber side 61. On the other hand, the lower reflective ring 69 is attached by fitting it from the lower side of the chamber side 61 and fastening it with screws (not shown). In other words, both reflective rings 68, 69 are detachably attached to the chamber side 61. The internal space of the chamber 6, i.e., the space surrounded by the upper chamber window 63, the lower chamber window 64, the chamber side 61, and the reflective rings 68, 69, is defined as a heat treatment space 65.

[0040] By attaching the reflecting rings 68, 69 to the chamber side portion 61, a recess 62 is formed on the inner wall surface of the chamber 6. That is, the recess 62 is formed by a central portion of the inner wall surface of the chamber side portion 61 where the reflecting rings 68, 69 are not attached, the lower end surface of the reflecting ring 68, and the upper end surface of the reflecting ring 69. The recess 62 is formed in an annular shape along the horizontal direction on the inner wall surface of the chamber 6, and surrounds the holder 7 that holds the semiconductor wafer W. The chamber side portion 61 and the reflecting rings 68, 69 are made of a metal material (e.g., stainless steel) that has excellent strength and heat resistance.

[0041] Furthermore, a transfer opening (furnace port) 66 is formed in the chamber side portion 61, through which a semiconductor wafer W is loaded into and unloaded from the chamber 6. The transfer opening 66 can be opened and closed by a gate valve 185. The transfer opening 66 is connected to the outer peripheral surface of the recessed portion 62. Therefore, when the gate valve 185 opens the transfer opening 66, the semiconductor wafer W can be loaded into and unloaded from the heat treatment space 65 through the transfer opening 66 and the recessed portion 62. Furthermore, when the gate valve 185 closes the transfer opening 66, the heat treatment space 65 in the chamber 6 becomes an airtight space.

[0042] Furthermore, through-holes 61a and 61b are formed in the chamber side portion 61. The through-hole 61a is a cylindrical hole for guiding infrared light radiated from the upper surface of a semiconductor wafer W held on a susceptor 74 (described later) 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 at an angle with respect to the horizontal direction so that their penetrating axes intersect with the main surface of the semiconductor wafer W held on the susceptor 74. A transparent window 26 made of calcium fluoride material that transmits infrared light in a wavelength range measurable by the upper radiation thermometer 25 is attached to the end of the through-hole 61a facing the heat treatment space 65. Furthermore, a transparent window 21 made of barium fluoride material that transmits infrared light in the wavelength range that can be measured by the lower radiation thermometer 20 is attached to the end of the through hole 61b facing the heat treatment space 65.

[0043] Gas supply holes 81 are formed in the upper part of the inner wall of the chamber 6 to supply processing gas to the heat treatment space 65. The gas supply holes 81 are formed at a position above the recess 62 and may be provided in the reflecting ring 68. The gas supply holes 81 are connected to a gas supply pipe 83 via a buffer space 82 formed in an annular shape inside the side wall of the chamber 6. The gas supply pipe 83 is connected to a processing gas supply source 85. A valve 84 is inserted in the gas supply pipe 83. When the valve 84 is opened, processing gas is supplied from the processing gas supply source 85 to the buffer space 82. The processing gas that has flowed into the buffer space 82 spreads within the buffer space 82, which has lower fluid resistance than the gas supply holes 81, and is supplied from the gas supply holes 81 into the heat treatment space 65. The processing gas may be, for example, an inert gas such as nitrogen (N), a reactive gas such as hydrogen (H) or ammonia (NH), or a mixture thereof (nitrogen gas in this embodiment).

[0044] Meanwhile, a gas exhaust hole 86 is formed in the lower part of the inner wall of the chamber 6 to exhaust gas from the heat treatment space 65. The gas exhaust hole 86 is formed below the recess 62 and may be provided in the reflecting ring 69. The gas exhaust hole 86 is connected to a gas exhaust pipe 88 via a buffer space 87 formed in an annular shape inside the side wall of the chamber 6. The gas exhaust pipe 88 is connected to an exhaust unit 190. A valve 89 is inserted in the gas exhaust pipe 88. When the valve 89 is opened, gas from the heat treatment space 65 is exhausted from the gas exhaust hole 86 through the buffer space 87 to the gas exhaust pipe 88. The gas supply hole 81 and the gas exhaust hole 86 may be provided in multiple numbers along the circumferential direction of the chamber 6, or may be slit-shaped. The process gas supply source 85 and the exhaust unit 190 may be mechanisms provided in the heat treatment apparatus 1 or may be utilities of a factory where the heat treatment apparatus 1 is installed.

[0045] A gas exhaust pipe 191 for discharging gas from the heat treatment space 65 is also connected to the tip of the transfer opening 66. The gas exhaust pipe 191 is connected to an exhaust unit 190 via a valve 192. By opening the valve 192, the gas in the chamber 6 is exhausted through the transfer opening 66.

[0046] 2 is a perspective view showing the overall appearance of the holder 7. The holder 7 is configured to include a base ring 71, a connecting portion 72, and a susceptor 74. The base ring 71, the connecting portion 72, and the susceptor 74 are all made of quartz. In other words, the entire holder 7 is made of quartz.

[0047] The base ring 71 is an arc-shaped quartz member with a portion missing from the annular shape. This missing portion is provided to prevent interference between the base ring 71 and a transfer arm 11 of the transfer mechanism 10, which will be described later. The base ring 71 is placed on the bottom surface of the recess 62, and is supported by the wall surface of the chamber 6 (see FIG. 1). A plurality of connecting portions 72 (four in this embodiment) are erected on the upper surface of the base ring 71 along the circumferential direction of the annular shape. The connecting portions 72 are also quartz members, and are fixed to the base ring 71 by welding.

[0048] The susceptor 74 is supported by four connecting portions 72 provided on the base ring 71. FIG. 3 is a plan view of the susceptor 74. FIG. 4 is a cross-sectional view of the susceptor 74. The susceptor 74 includes a holding plate 75, a guide ring 76, and a plurality of substrate support pins 77. The holding plate 75 is a substantially circular, flat member made of quartz. The diameter of the holding plate 75 is larger than the diameter of the semiconductor wafer W. That is, the holding plate 75 has a planar size larger than that of the semiconductor wafer W.

[0049] A guide ring 76 is installed on the periphery of the upper surface of the holding plate 75. The guide ring 76 is an annular member having an inner diameter larger than the diameter of the semiconductor wafer W. For example, if the diameter of the semiconductor wafer W is φ300 mm, the inner diameter of the guide ring 76 is φ320 mm. The inner periphery of the guide ring 76 has a tapered surface that widens upward from the holding plate 75. The guide ring 76 is made of quartz, the same as the holding plate 75. The guide ring 76 may be welded to the upper surface of the holding plate 75, or may be fixed to the holding plate 75 by a separately processed pin or the like. Alternatively, the holding plate 75 and the guide ring 76 may be processed as an integrated member.

[0050] The area of ​​the upper surface of the holding plate 75 that is inside the guide ring 76 is a flat holding surface 75a that holds the semiconductor wafer W. A plurality of substrate support pins 77 are provided on the holding surface 75a of the holding plate 75. In this embodiment, a total of 12 substrate support pins 77 are provided at 30° intervals along a circumference concentric with the outer circumferential circle of the holding surface 75a (the inner circumferential circle of the guide ring 76). The diameter of the circle on which the 12 substrate support pins 77 are arranged (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 300 mm, the diameter is 270 mm to 280 mm (270 mm in this embodiment). Each substrate support pin 77 is made of quartz. The plurality of substrate support pins 77 may be provided on the upper surface of the holding plate 75 by welding, or may be machined integrally with the holding plate 75.

[0051] Returning to FIG. 2, four connecting portions 72 erected on the base ring 71 are fixed to the peripheral edge of the holding plate 75 of the susceptor 74 by welding. That is, the susceptor 74 and the base ring 71 are fixedly connected by the connecting portions 72. The base ring 71 of the holding portion 7 is supported on the wall surface of the chamber 6, and the holding portion 7 is thereby attached to the chamber 6. When the holding portion 7 is attached to the chamber 6, the holding plate 75 of the susceptor 74 is in a horizontal position (a position in which the normal line coincides with the vertical direction). That is, the holding surface 75a of the holding plate 75 is a horizontal plane.

[0052] The semiconductor wafer W carried into the chamber 6 is placed and held in a horizontal position on the susceptor 74 of the holder 7 attached to the chamber 6. At this time, the semiconductor wafer W is supported by twelve substrate support pins 77 erected on a holding plate 75 and held on the susceptor 74. More precisely, the upper ends of the twelve substrate support pins 77 contact the underside of the semiconductor wafer W to support the semiconductor wafer W. The heights of the twelve substrate support pins 77 (the distance from the upper ends of the substrate support pins 77 to the holding surface 75a of the holding plate 75) are uniform, so the twelve substrate support pins 77 can support the semiconductor wafer W in a horizontal position.

[0053] Furthermore, the semiconductor wafer W is supported by a plurality of substrate support pins 77 at a predetermined distance from the holding surface 75a of the holding plate 75. 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.

[0054] 2 and 3, an opening 78 is formed in the holding plate 75 of the susceptor 74, penetrating vertically. The opening 78 is provided so that the lower radiation thermometer 20 can receive radiation (infrared light) emitted from the underside of the semiconductor wafer W. That is, the lower radiation thermometer 20 receives the light emitted from the underside of the semiconductor wafer W through the opening 78 and a transparent window 21 attached to the through-hole 61b of the chamber side 61, thereby measuring the temperature of the semiconductor wafer W. Furthermore, the holding plate 75 of the susceptor 74 is provided with four through-holes 79 through which lift pins 12 of the transfer mechanism 10, which will be described later, penetrate to transfer the semiconductor wafer W. In this embodiment, a portion of the underside of the holding plate 75 of the susceptor 74 is roughened to reduce transmittance, as will be described further below.

[0055] FIG. 5 is a plan view of the transfer mechanism 10. FIG. 6 is a side view of the transfer mechanism 10. The transfer mechanism 10 includes two transfer arms 11. The transfer arms 11 are arc-shaped so as to fit the generally annular recess 62. Two lift pins 12 are provided on each of the transfer arms 11. The transfer arms 11 and the lift pins 12 are made of quartz. Each transfer arm 11 is rotatable by a horizontal movement mechanism 13. The horizontal movement mechanism 13 horizontally moves the pair of transfer arms 11 between a transfer operation position (position indicated by a solid line in FIG. 5) where the transfer arms 11 transfer the semiconductor wafer W to the holder 7 and a retracted position (position indicated by a two-dot chain line in FIG. 5) where the transfer arms 11 do not overlap the semiconductor wafer W held by the holder 7 in a plan view. The horizontal movement mechanism 13 may be one that rotates each transfer arm 11 using an individual motor, or one that uses a link mechanism to rotate a pair of transfer arms 11 in conjunction with one another using a single motor.

[0056] Furthermore, the pair of transfer arms 11 are raised and lowered together with the horizontal movement mechanism 13 by the lifting mechanism 14. When the lifting mechanism 14 raises the pair of transfer arms 11 to the transfer operation position, a total of four lift pins 12 pass through through holes 79 (see FIGS. 2 and 3 ) formed in the susceptor 74, and the upper ends of the lift pins 12 protrude from the upper surface of the susceptor 74. On the other hand, when the lifting mechanism 14 lowers the pair of transfer arms 11 to the transfer operation position to remove the lift pins 12 from the through holes 79, and the horizontal movement mechanism 13 moves the pair of transfer arms 11 so as to open, each transfer arm 11 moves to a retracted position. The retracted position of the pair of transfer arms 11 is directly above the base ring 71 of the holder 7. Because the base ring 71 is placed on the bottom surface of the recess 62, the retracted position of the transfer arms 11 is inside the recess 62. In addition, an exhaust mechanism (not shown) is also provided near the location where the drive part of the transfer mechanism 10 (horizontal movement mechanism 13 and lifting mechanism 14) is located, and is configured to exhaust the atmosphere around the drive part of the transfer mechanism 10 to the outside of the chamber 6.

[0057] Returning to FIG. 1 , the flash heating unit 5, which is provided above the chamber 6, is configured with a light source made up of multiple (30 in this embodiment) xenon flash lamps FL inside a housing 51, and a reflector 52 provided to cover the light source from above. A lamp light emission window 53 is attached to the bottom of the housing 51 of the flash heating unit 5. The lamp light emission window 53, which forms the floor of the flash heating unit 5, is a plate-shaped quartz window made of quartz. By installing the flash heating unit 5 above the chamber 6, the lamp light emission window 53 faces the upper chamber window 63. The flash lamps FL irradiate a heat treatment space 65 with flash light from above the chamber 6 through the lamp light emission window 53 and the upper chamber window 63.

[0058] The flash lamps FL are each a rod-shaped lamp having a long cylindrical shape, and are arranged in a plane so that their longitudinal directions are parallel to each other along the main surface of the semiconductor wafer W held by the holder 7 (i.e., along the horizontal direction). Therefore, the plane formed by the arrangement of the flash lamps FL is also a horizontal plane. The area in which the flash lamps FL are arranged is larger than the planar size of the semiconductor wafer W.

[0059] A xenon flash lamp FL comprises a cylindrical glass tube (discharge tube) filled with xenon gas and fitted with an anode and cathode connected to a capacitor at both ends, and a trigger electrode attached to the outer surface of the glass tube. Because xenon gas is an electrical insulator, electricity does not flow within the glass tube under normal conditions, even if a charge is stored in the capacitor. However, when a high voltage is applied to the trigger electrode, causing the insulation to break down, the electricity stored in the capacitor flows instantaneously within the glass tube, exciting the xenon atoms or molecules and emitting light. In such a xenon flash lamp FL, electrostatic energy previously stored in the capacitor is converted into extremely short light pulses of 0.1 to 100 milliseconds, enabling it to emit extremely intense light compared to continuous light sources such as halogen lamps HL. In other words, a flash lamp FL is a pulsed lamp that emits light instantaneously for an extremely short period of time, less than one second. The light emission time of the flash lamp FL can be adjusted by adjusting the coil constant of the lamp power supply that supplies power to the flash lamp FL.

[0060] Furthermore, reflector 52 is provided above the multiple flash lamps FL so as to cover them entirely. The basic function of reflector 52 is to reflect the flash light emitted from the multiple flash lamps FL toward the heat treatment space 65. Reflector 52 is made of an aluminum alloy plate, and its surface (the surface facing the flash lamps FL) is roughened by blasting.

[0061] The halogen heating unit 4, which is provided below the chamber 6, has a plurality of halogen lamps HL (40 in this embodiment) built into the inside of the housing 41. The halogen heating unit 4 is a light irradiation unit that heats the semiconductor wafer W by irradiating light from the plurality of halogen lamps HL from below the chamber 6 through a lower chamber window 64 into a heat treatment space 65.

[0062] FIG. 7 is a plan view showing the arrangement of multiple halogen lamps HL. 40 halogen lamps HL are arranged in two rows, upper and lower. 20 halogen lamps HL are arranged in the upper row, which is closer to the holder 7, and 20 halogen lamps HL are also arranged in the lower row, which is farther from the holder 7 than the upper row. Each halogen lamp HL is a rod-shaped lamp having a long cylindrical shape. In both the upper and lower rows, the 20 halogen lamps HL are arranged so that their longitudinal directions are parallel to each other along the main surface of the semiconductor wafer W held by the holder 7 (i.e., along the horizontal direction). Therefore, the plane formed by the arrangement of the halogen lamps HL in both the upper and lower rows is a horizontal plane.

[0063] 7, the halogen lamps HL are arranged more densely in the region facing the periphery of the semiconductor wafer W held by the holder 7 on both the upper and lower tiers than in the region facing the center of the semiconductor wafer W. That is, on both the upper and lower tiers, the halogen lamps HL are arranged at a shorter pitch in the periphery of the lamp arrangement than in the center. This allows a greater amount of light to be irradiated onto the periphery of the semiconductor wafer W, which is prone to temperature drop during heating due to light irradiation from the halogen heating unit 4.

[0064] The lamp group consisting of the halogen lamps HL on the upper row and the lamp group consisting of the halogen lamps HL on the lower row are arranged so as to intersect in a grid pattern. That is, a total of 40 halogen lamps HL are arranged so that the longitudinal direction of the 20 halogen lamps HL arranged on the upper row and the longitudinal direction of the 20 halogen lamps HL arranged on the lower row are perpendicular to each other.

[0065] A halogen lamp HL is a filament-type light source that emits light by passing electricity through a filament placed inside a glass tube, causing it to incandescent. The glass tube is filled with an inert gas, such as nitrogen or argon, containing trace amounts of halogen elements (iodine, bromine, etc.). The introduction of halogen elements makes it possible to set the filament temperature at a high temperature while preventing filament breakage. Therefore, compared to standard incandescent light bulbs, halogen lamps HL have the characteristics of a longer lifespan and the ability to continuously emit strong light. In other words, halogen lamps HL are continuous lamps that emit light continuously for at least one second. Furthermore, because halogen lamps HL are rod-shaped, they have a long lifespan, and by arranging them horizontally, they achieve excellent radiation efficiency toward the semiconductor wafer W above.

[0066] Also, a reflector 43 is provided below the two-tiered halogen lamps HL inside the housing 41 of the halogen heating unit 4 (FIG. 1). The reflector 43 reflects the light emitted from the multiple halogen lamps HL toward the heat treatment space 65.

[0067] A louver 49 is provided between the halogen heating unit 4 and the lower chamber window 64 of the chamber 6 (FIG. 1). The louver 49 is a cylindrical member (bottomless cylindrical member) with open ends at the top and bottom. The louver 49 is made of a material that is opaque to the light emitted from the halogen lamps HL of the halogen heating unit 4, such as opaque quartz made of quartz glass containing numerous fine bubbles. The size of the louver 49 can be determined appropriately depending on the arrangement of the chamber 6 and the halogen heating unit 4. The outer diameter of the cylinder of the louver 49 needs only to be smaller than the area where the halogen lamps HL are located. For example, the outer diameter of the louver 49 is 300 mm, the same as the diameter of the semiconductor wafer W, and the inner diameter is 294 mm. The height of the louver 49 may be, for example, 15 mm to 25 mm. The central axis of the cylindrical louver 49 passes through the center of the semiconductor wafer W held by the susceptor 74.

[0068] As shown in FIG. 1, the heat treatment apparatus 1 includes an upper radiation thermometer 25 and a lower radiation thermometer 20. The upper radiation thermometer 25 is installed diagonally above the semiconductor wafer W held on the susceptor 74 and receives infrared light radiated from the top surface of the semiconductor wafer W to measure the temperature of the top surface. The infrared sensor 29 of the upper radiation thermometer 25 includes an InSb (indium antimonide) optical element to respond to the sudden temperature change on the top surface of the semiconductor wafer W at the moment when the flash light is irradiated. On the other hand, the lower radiation thermometer 20 is installed diagonally below the semiconductor wafer W held on the susceptor 74 and receives infrared light radiated from the bottom surface of the semiconductor wafer W to measure the temperature of the bottom surface.

[0069] The control unit 3 controls the various operating mechanisms provided in the heat treatment device 1. The hardware configuration of the control unit 3 is similar to that of a general computer. That is, the control unit 3 includes a CPU, which is a circuit that performs various arithmetic processing, a ROM, which is a read-only memory that stores basic programs, a RAM, which is a read / write memory that stores various information, and a magnetic disk that stores control software, data, etc. The processing in the heat treatment device 1 progresses as the CPU of the control unit 3 executes a predetermined processing program.

[0070] In this embodiment, a roughening process is applied to a portion of the holding plate 75 of the susceptor 74. Specifically, on the lower surface of the holding plate 75, a processed region located between adjacent substrate support pins 77 is subjected to sandblasting to make the surface rough.

[0071] 8 is a diagram showing an example of the temperature distribution that occurs within the wafer surface when light is irradiated from the halogen lamps HL while the semiconductor wafer W is held on an unprocessed susceptor 74. When 40 halogen lamps HL are arranged in two tiers, upper and lower, as in this embodiment, the amount of light irradiated from the halogen heating unit 4 toward the center of the semiconductor wafer W becomes relatively large.

[0072] For this reason, in this embodiment, louvers 49 are provided between the multiple halogen lamps HL of the halogen heating unit 4 and the susceptor 74 of the holder 7. When light is irradiated from the multiple halogen lamps HL, the light directed toward the vicinity of the center of the semiconductor wafer W from the halogen lamps HL located outside the louvers 49 is blocked by the opaque walls of the louvers 49. On the other hand, the light directed toward the peripheral portion of the semiconductor wafer W from the halogen lamps HL located outside the louvers 49 is not blocked. In other words, by providing the louvers 49, the light directed toward the peripheral portion of the semiconductor wafer W from the halogen lamps HL is hardly reduced, but the light directed toward the center is reduced. As a result, heating near the center of the semiconductor wafer W, where hot spots are likely to occur, is weakened, while the peripheral portion of the semiconductor wafer W, where temperature drops are likely to occur, is heated relatively more strongly.

[0073] However, simply installing louvers 49 above the halogen heating unit 4 can result in a hot spot occurring in an area slightly inside the periphery of the semiconductor wafer W when the semiconductor wafer W is heated by light irradiation from the multiple halogen lamps HL. A hot spot is an area that is relatively hotter than other areas within the surface of the semiconductor wafer W.

[0074] As described above, twelve substrate support pins 77 are provided on the upper surface of the holding plate 75 of the susceptor 74 at equal intervals along the same circumference of a circle measuring φ270 mm to φ280 mm. The semiconductor wafer W is supported by these twelve substrate support pins 77. By providing the louvers 49, the amount of light irradiated to the area of ​​the semiconductor wafer W near the circle on which the twelve substrate support pins 77 are provided (hereinafter also referred to as the "pin installation circle") is relatively increased, causing the area to become hot. However, areas in direct contact with the substrate support pins 77 are less likely to become hot due to heat conduction to the substrate support pins 77. As a result, as shown in FIG. 8 , when light is irradiated from forty halogen lamps HL, hot spots 99 appear on the surface of the semiconductor wafer W in the area along the circumference of the pin installation circle, excluding the contact points 77a with the substrate support pins 77. The inventors have previously determined the in-plane temperature distribution as shown in FIG. 8 through experiments or simulations using a susceptor 74 that has not been subjected to any particular processing.

[0075] In this embodiment, based on the non-uniformity of the in-plane temperature distribution as shown in Fig. 8, processing areas on the underside of the holding plate 75 located between adjacent substrate support pins 77 are sandblasted to roughen the surface and reduce transmittance. Fig. 9 is a plan view of the holding plate 75 viewed from below. Of the 12 substrate support pins 77 arranged at equal intervals (30° intervals) along the circumference of the pin arrangement circle 73, 12 processing areas 95 located between adjacent substrate support pins 77 are roughened. The 12 processing areas 95 are also arranged along the circumference of the pin arrangement circle 73. These processing areas 95 face hot spots 99 that appear on the semiconductor wafer W held by the susceptor 74.

[0076] FIG. 10 is an enlarged view of the vicinity of one processing region 95. Each processing region 95 located between adjacent substrate support pins 77 has an oval shape. An oval shape is a shape that broadly includes rounded, horizontally elongated curves and is composed of differentiable (smooth) curves. An oval shape is composed of non-intersecting, convex, closed curves. Examples of oval shapes include elliptical shapes, long hole shapes, and egg shapes. More specifically, the processing region 95 of this embodiment is essentially an elongated hole shape that follows the circumference of the pin arrangement circle 73. The two curves along the longitudinal direction of the processing region 95 are arcs concentric with the pin arrangement circle 73. The width of the processing region 95 (the length along the radial direction of the pin arrangement circle 73) is, for example, 15 mm. The longitudinal length of the processing region 95 (the length along the circumferential direction of the pin arrangement circle 73) is a value that covers, for example, 20° of the pin arrangement circle 73.

[0077] Furthermore, the center of gravity 93 of the oval shape of the processing area 95 coincides with the midpoint along the circumference of the pin arrangement circle 73 of adjacent board support pins 77 that sandwich the processing area 95. In the case where adjacent board support pins 77 are arranged at an interval of 30° as in this embodiment, the center of gravity 93 of the processing area 95 is located at a position 15° from both board support pins 77 on the circumference of the pin arrangement circle 73.

[0078] The 12 processing areas 95 are roughened by sandblasting. Sandblasting is a processing method in which compressed air mixed with an abrasive (sand) is sprayed onto an object. The grit size of the abrasive used in sandblasting is equal to or greater than 240 and equal to or less than 800 according to the Japanese Industrial Standards (JIS) (600 in this embodiment). The smaller the grit size (grit), the coarser the abrasive (the larger the average particle diameter). Therefore, the smaller the grit size, the greater the surface roughness (rougher) of the processing area 95 after processing, and the lower its transmittance.

[0079] If the grit size of the abrasive used in sandblasting is less than 240, the surface roughness of the processed area 95 after processing will be excessively large, significantly reducing the transmittance of the processed area 95. In this case, the area of ​​the semiconductor wafer W facing the processed area 95 will be shaded by the processed area 95 when irradiated with light from the halogen lamp HL, and this area may become a cold spot because almost no light reaches it. Conversely, if the grit size of the abrasive used in sandblasting is greater than 800, the surface roughness of the processed area 95 after processing will be excessively small, and the processed area 95 will resemble a smooth surface rather than a rough surface. In this case, the transmittance of the processed area 95 will not decrease, and the light-reducing effect of the processed area 95 will be almost completely eliminated. For these reasons, the grit size of the abrasive used in sandblasting is set to be greater than 240 and less than 800.

[0080] When sandblasting is performed on the processing area 95 using an abrasive with a grit size of 240, the surface roughness (arithmetic mean roughness (Ra)) of the processing area 95 is 2.0 μm. On the other hand, when sandblasting is performed on the processing area 95 using an abrasive with a grit size of 800, the surface roughness of the processing area 95 is 0.2 μm. In other words, if the grit size of the abrasive used for sandblasting is 240 or more and 800 or less, the surface roughness of the processing area 95 after processing will be 0.2 μm or more and 2.0 μm or less.

[0081] In addition to the above configuration, the heat treatment apparatus 1 is equipped with various cooling structures to prevent excessive temperature rise in the halogen heating unit 4, flash heating unit 5, and chamber 6 due to the thermal energy generated by the halogen lamps HL and flash lamps FL during heat treatment of the semiconductor wafer W. For example, a water-cooled pipe (not shown) is provided in the wall of the chamber 6. The halogen heating unit 4 and flash heating unit 5 also have an air-cooled structure that creates a gas flow inside to remove heat. Air is also supplied to the gap between the upper chamber window 63 and the lamp light emission window 53 to cool the flash heating unit 5 and upper chamber window 63.

[0082] Next, a description will be given of the processing operation in the heat treatment apparatus 1. Here, a description will be given of a typical heat treatment operation for a normal semiconductor wafer (product wafer) W that will become a product. The processing procedure for the semiconductor wafer W described below progresses as the control unit 3 controls each operating mechanism of the heat treatment apparatus 1.

[0083] First, the air supply valve 84 is opened, and the exhaust valves 89, 192 are also opened to start supplying and exhausting air to and from the chamber 6. When the valve 84 is opened, nitrogen gas is supplied to the heat treatment space 65 through the gas supply hole 81. When the valve 89 is opened, the gas inside the chamber 6 is exhausted through the gas exhaust hole 86. As a result, the nitrogen gas supplied from the upper part of the heat treatment space 65 inside the chamber 6 flows downward and is exhausted from the lower part of the heat treatment space 65.

[0084] Furthermore, by opening the valve 192, the gas inside the chamber 6 is also exhausted from the transfer opening 66. Furthermore, the atmosphere around the drive unit of the transfer mechanism 10 is also exhausted by an exhaust mechanism (not shown). Note that during the heat treatment of the semiconductor wafer W in the heat treatment apparatus 1, nitrogen gas is continuously supplied to the heat treatment space 65, and the supply amount is changed as appropriate depending on the treatment process.

[0085] Next, gate valve 185 is opened to open transfer opening 66, and a semiconductor wafer W to be processed is carried into heat treatment space 65 in chamber 6 through transfer opening 66 by a transfer robot outside the apparatus. At this time, there is a risk that the atmosphere outside the apparatus may be drawn in as the semiconductor wafer W is carried in, but since nitrogen gas is continuously supplied to chamber 6, the nitrogen gas flows out from transfer opening 66, making it possible to minimize the drawing in of such external atmosphere.

[0086] The semiconductor wafer W carried in by the transfer robot advances to a position directly above the holder 7 and stops there. Then, the pair of transfer arms 11 of the transfer mechanism 10 move horizontally from the retracted position to the transfer operation position and rise, causing the lift pins 12 to pass through the through holes 79 and protrude from the upper surface of the holding plate 75 of the susceptor 74 to receive the semiconductor wafer W. At this time, the lift pins 12 rise to a position higher than the upper ends of the substrate support pins 77.

[0087] After the semiconductor wafer W is placed on the lift pins 12, the transfer robot exits the heat treatment space 65, and the transfer opening 66 is closed by the gate valve 185. Then, the pair of transfer arms 11 descend, transferring the semiconductor wafer W from the transfer mechanism 10 to the susceptor 74 of the holder 7, where it is held horizontally from below. The semiconductor wafer W is supported by a plurality of substrate support pins 77 erected on a holding plate 75 and held on the susceptor 74. The semiconductor wafer W is held on the holder 7 with its patterned surface facing up. A predetermined gap is formed between the back surface (the main surface 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, which have descended to below the susceptor 74, are retracted to a retracted position, i.e., inside the recess 62, by the horizontal movement mechanism 13.

[0088] After the semiconductor wafer W is held from below in a horizontal position by the susceptor 74 of the holder 7, which is made of quartz, the 40 halogen lamps HL of the halogen heating unit 4 are turned on all at once to begin preheating (assisted heating). The halogen light emitted from the halogen lamps HL passes through the lower chamber window 64 and the susceptor 74, both of which are made of quartz, and is irradiated onto the underside of the semiconductor wafer W. The semiconductor wafer W is preheated by being irradiated with light from the halogen lamps HL, and its temperature rises. Note that the transfer arm 11 of the transfer mechanism 10 is retracted inside the recess 62, so it does not interfere with heating by the halogen lamps HL.

[0089] In this embodiment, a processing area 95 on the underside of the holding plate 75 located between adjacent substrate support pins 77 is roughened by sandblasting. Therefore, the transmittance of the processing area 95 is lower than that of other areas, and the amount of light irradiated onto a hot spot 99 of the semiconductor wafer W facing the processing area 95 is reduced, thereby reducing the temperature of the hot spot 99. As a result, the uniformity of the in-plane temperature distribution of the semiconductor wafer W when irradiated with light from the halogen lamps HL can be improved.

[0090] When preheating is performed using the halogen lamps 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 underside of the semiconductor wafer W held on the susceptor 74 through the openings 78 and transmits it through the transparent window 21 to measure the wafer temperature during heating. The measured temperature of the semiconductor wafer W is transmitted to the control unit 3. The control unit 3 controls the output of the halogen lamps HL while monitoring whether the temperature of the semiconductor wafer W, which is heated by the light irradiation from the halogen lamps HL, has reached a predetermined preheating temperature T1. That is, the control unit 3 performs feedback control of the output of the halogen lamps HL based on the measurement value by the lower radiation thermometer 20 so that the temperature of the semiconductor wafer W becomes the preheating temperature T1. In this way, the lower radiation thermometer 20 is a radiation thermometer for controlling the temperature of the semiconductor wafer W during preheating.

[0091] After the temperature of the semiconductor wafer W reaches the preheating temperature T1, the control unit 3 temporarily maintains the semiconductor wafer W at the preheating temperature T1. Specifically, when the temperature of the semiconductor wafer W measured by the lower radiation thermometer 20 reaches the preheating temperature T1, the control unit 3 adjusts the output of the halogen lamps HL to maintain the temperature of the semiconductor wafer W at approximately the preheating temperature T1.

[0092] When a predetermined time has elapsed since the temperature of the semiconductor wafer W reached the preheating temperature T1, the flash lamps FL of the flash heating unit 5 irradiate the surface of the semiconductor wafer W held on the susceptor 74 with flash light. At this time, part of the flash light emitted from the flash lamps FL heads directly into the chamber 6, and the other part is reflected by the reflector 52 before heading into the chamber 6, and the semiconductor wafer W is flash-heated by the irradiation of these flash lights.

[0093] Flash heating is performed by irradiating a flash of light (flash of light) from flash lamps FL, which allows the surface temperature of the semiconductor wafer W to rise in a short time. That is, the flash of light irradiated from the flash lamps FL is an extremely short, intense flash of light with an irradiation time of approximately 0.1 milliseconds to 100 milliseconds, in which electrostatic energy previously stored in a capacitor is converted into an extremely short light pulse. The surface temperature of the semiconductor wafer W flash-heated by the irradiation of the flash of light from the flash lamps FL instantaneously rises to the processing temperature T2 and then rapidly drops.

[0094] After the flash heating process is completed, the halogen lamps HL are turned off after a predetermined time has elapsed. This causes the temperature of the semiconductor wafer W to rapidly decrease from the preheating temperature T1. The temperature of the semiconductor wafer W during this decrease is measured by the lower radiation thermometer 20, and the measurement result is transmitted to the control unit 3. The control unit 3 monitors, based on the measurement result of the lower radiation thermometer 20, whether the temperature of the semiconductor wafer W has decreased to a predetermined temperature. After the temperature of the semiconductor wafer W has decreased to or below the predetermined temperature, the pair of transfer arms 11 of the transfer mechanism 10 again move horizontally from the retracted position to the transfer operation position and rise, causing the lift pins 12 to protrude from the upper surface of the susceptor 74 and receive the heat-treated semiconductor wafer W from the susceptor 74. Next, the transfer opening 66, which had been closed by the gate valve 185, is opened, and the semiconductor wafer W placed on the lift pins 12 is removed from the chamber 6 by a transfer robot external to the apparatus, completing the heat treatment of the semiconductor wafer W.

[0095] In this embodiment, a processing area 95 on the underside of the holding plate 75, which is located between adjacent substrate support pins 77 among the plurality of substrate support pins 77 erected on the holding plate 75, is sandblasted to roughen the surface and reduce transmittance. The processing area 95 faces a hot spot 99 that appears on the semiconductor wafer W held on the susceptor 74. Therefore, the amount of light emitted from the plurality of halogen lamps HL and directed toward the hot spot 99 during preheating is reduced by the roughened processing area 95. As a result, the temperature of the hot spot 99 can be reduced, thereby improving the uniformity of the in-plane temperature distribution of the semiconductor wafer W during preheating. This not only improves the yield of the semiconductor wafer W, but also suppresses cracking of the semiconductor wafer W due to uneven temperature distribution.

[0096] Although the embodiments of the present invention have been described above, various modifications can be made to the present invention without departing from the spirit and scope of the invention. For example, in the above-described embodiment, the shape of the processing region 95 is substantially an elongated hole shape along the circumference of the pin arrangement circle 73. However, this is not limited to this, and the shape of the processing region 95 may be, for example, as shown in FIG. 11 or FIG. 12. FIGS. 11 and 12 are diagrams showing other examples of the shape of the processing region 95. The processing region 95 shown in FIG. 11 is oval (elliptical). The processing region 95 shown in FIG. 12 is elongated hole-shaped with two parallel lines along the longitudinal direction. Regardless of the shape, the processing region 95 is located between adjacent board support pins 77, and the same effect as the above-described embodiment can be obtained. Alternatively, the shape of the processing region 95 may be a perfect circle or a rectangle.

[0097] Furthermore, in the above embodiment, the surface roughness of the processing region 95 after processing was 0.2 μm or more and 2.0 μm or less, but the surface roughness of each of the multiple processing regions 95 may be different values ​​as long as it is within this range. Specifically, in the in-plane temperature distribution (e.g., the temperature distribution shown in FIG. 8 ) that occurs on the semiconductor wafer W supported by the multiple substrate support pins 77 when light from the halogen lamps HL is irradiated on the semiconductor wafer W, the surface roughness of the processing region 95 facing the relatively high temperature region is made larger than the surface roughness of the processing region 95 facing the relatively low temperature region in the in-plane temperature distribution that occurs on the semiconductor wafer W. In other words, the particle size of the abrasive used in the sandblasting process performed on the processing region 95 facing the relatively high temperature region is made smaller than the particle size of the abrasive used in the sandblasting process performed on the processing region 95 facing the relatively low temperature region in the in-plane temperature distribution that occurs on the semiconductor wafer W. In this way, the amount of light directed toward areas with higher temperatures in the in-plane temperature distribution occurring on the semiconductor wafer W is significantly reduced, making it possible to further improve the uniformity of the in-plane temperature distribution on the semiconductor wafer W.

[0098] Furthermore, in the above embodiment, sandblasting is performed on all of the 12 processing regions 95 present between adjacent substrate support pins 77 among the 12 substrate support pins 77, but this is not limited to this, and only some of the processing regions 95 may be roughened. For example, sandblasting may be performed on only the processing region 95 facing a hot spot 99 that is higher in temperature than the surrounding area by a certain threshold or more in the in-plane temperature distribution occurring on the semiconductor wafer W, to roughen the surface.

[0099] In the above embodiment, sandblasting is used to roughen the processing area 95, but this is not limiting and other chemical or physical methods may be used. For example, the processing area 95 may be roughened by etching using a predetermined chemical solution. Alternatively, the processing area 95 may be roughened by grinding.

[0100] Furthermore, in the above embodiment, the louvers 49 are provided to adjust the illuminance distribution, but the louvers 49 are not an essential element. Alternatively, instead of or in addition to the louvers 49, other illuminance adjusting members such as flat, opaque quartz members may be provided.

[0101] Furthermore, in the above embodiment, the flash heating unit 5 is provided with 30 flash lamps FL, but this is not limited to this and the number of flash lamps FL can be any number. Furthermore, the flash lamps FL are not limited to xenon flash lamps and may be krypton flash lamps. Furthermore, the number of halogen lamps HL provided in the halogen heating unit 4 is not limited to 40 and can be any number.

[0102] Furthermore, in the above embodiment, the semiconductor wafer W is preheated using a filament-type halogen lamp HL as a continuously lit lamp that emits light continuously for one second or more, but this is not limited to this, and preheating may be performed using a discharge arc lamp (e.g., a xenon arc lamp) or an LED lamp as a continuously lit lamp instead of the halogen lamp HL. [Explanation of symbols]

[0103] 1. Heat treatment equipment 3. Control Unit 4 Halogen heating section 5 Flash heating section 6 chambers 7 Holding part 10 Transfer mechanism 20 Lower radiation thermometer 25 Upper radiation thermometer 49 Louver 63 Upper chamber window 64 Lower chamber window 65 Heat Treatment Space 73 Pinout Circle 74 Susceptor 75 Retaining Plate 77 PCB support pin 93 Center of gravity position 95 Processing area FL flash lamp HL halogen lamp W Semiconductor wafer

Claims

1. A susceptor for supporting a substrate that is heated by light irradiation, a flat holding plate made of quartz; a plurality of substrate support pins made of quartz and erected on the holding plate to support the substrate; Equipped with A susceptor in which a part or all of a plurality of processing regions of the holding plate located between adjacent ones of the plurality of substrate support pins are roughened.

2. The susceptor of claim 1 , the plurality of substrate support pins are arranged at equal intervals on the same circumference, The plurality of processing regions are provided along the circumference of the susceptor.

3. The susceptor according to claim 2, The susceptor has a plurality of processing regions each having an oval shape.

4. The susceptor according to claim 3, A susceptor in which the center of gravity of the oval shape coincides with the midpoint along the circumference of adjacent substrate support pins that sandwich the processing region of the oval shape.

5. The susceptor according to claim 2, Each of the plurality of processing regions of the susceptor has an oval shape or an elongated hole shape.

6. The susceptor of claim 1 , The rough surface of the susceptor has a surface roughness of 0.2 μm or more and 2.0 μm or less.

7. The susceptor according to claim 6, A susceptor that makes the surface roughness of the roughened surface of the processing region of the holding plate facing the region where the temperature is relatively high in the temperature distribution that occurs in the substrate when light is irradiated onto the substrate supported by the multiple substrate support pins greater than the surface roughness of the roughened surface of the processing region of the holding plate facing the region where the temperature is relatively low.

8. A heat treatment apparatus that heats a substrate by irradiating the substrate with light, a chamber for accommodating the substrate; a susceptor according to any one of claims 1 to 7, which is provided in the chamber and supports the substrate; a continuously lit lamp that irradiates light from below the chamber to heat the substrate; A heat treatment device comprising:

9. 9. The heat treatment apparatus according to claim 8, The heat treatment apparatus further comprises a light blocking member disposed between the susceptor and the continuously lit lamp.

10. 9. The heat treatment apparatus according to claim 8, The heat treatment apparatus further comprises a flash lamp that irradiates the substrate with a flash of light from above the chamber.

11. A method for manufacturing a susceptor for supporting a substrate heated by light irradiation, comprising the steps of: A method for manufacturing a susceptor, comprising roughening part or all of a plurality of processing areas of a flat holding plate made of quartz, the processing areas being located between adjacent substrate support pins among a plurality of substrate support pins erected on the holding plate.

12. The method for manufacturing a susceptor according to claim 11, the plurality of substrate support pins are arranged at equal intervals on the same circumference, The method for manufacturing a susceptor, wherein the plurality of processing regions are provided along the circumference.

13. The method for manufacturing a susceptor according to claim 12, A method for manufacturing a susceptor, wherein each of the plurality of processing regions is oval-shaped.

14. The method for manufacturing a susceptor according to claim 13, A method for manufacturing a susceptor, wherein the center of gravity of the oval shape coincides with the midpoint along the circumference of adjacent substrate support pins that sandwich the processing region of the oval shape.

15. The method for manufacturing a susceptor according to claim 12, A method for manufacturing a susceptor, wherein each of the plurality of processing regions has an oval shape or an elongated hole shape.

16. The method for manufacturing a susceptor according to claim 11, The method for manufacturing a susceptor, wherein the surface roughening process is sandblasting.

17. The method for manufacturing a susceptor according to claim 16, The method for manufacturing a susceptor, wherein the grain size of the abrasive used in the sandblasting is equal to or larger than 240 and equal to or smaller than 800.

18. The method for manufacturing a susceptor according to claim 17, A method for manufacturing a susceptor, wherein the grain size of the abrasive used in the sandblasting process performed on a processing area of ​​the holding plate facing a region where the temperature is relatively high in the temperature distribution that occurs in the substrate when light is irradiated onto the substrate supported by the plurality of substrate support pins is made smaller than the grain size of the abrasive used in the sandblasting process performed on a processing area of ​​the holding plate facing a region where the temperature is relatively low.

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