Heat treatment susceptor and heat treatment device

Abstract

The present invention aims to provide a heat treatment base and a heat treatment apparatus that are simple in structure and can prevent the substrate from jumping and cracking during flash irradiation. The heat treatment base (74) holds a semiconductor wafer (W) when the semiconductor substrate (W) is heat-treated by irradiating the substrate with flash from a flash lamp, and comprises: a holding plate (75) having a planar holding surface (75a); and a plurality of substrate support pins (77) erected on the holding surface (75a). A gap (78) is formed around the upright position of at least one substrate support pin (77) of the holding plate (75). The gap (78) has at least one curved portion (78t).

Description

Technical Field

[0001] The present invention relates to a heat treatment susceptor for holding a thin plate-shaped precision electronic substrate (hereinafter referred to as "substrate") such as a semiconductor wafer when heat treatment of the substrate is performed by irradiating the substrate with flash light from a flash lamp, and a heat treatment device including the heat treatment susceptor. Background Art

[0002] In the semiconductor device manufacturing process, impurity introduction is a necessary step for forming a pn junction within the semiconductor wafer. Currently, impurity introduction is generally accomplished through ion implantation and subsequent annealing. Ion implantation involves ionizing impurity elements such as boron (B), arsenic (As), and phosphorus (P), and then colliding them with the semiconductor wafer at a high acceleration voltage to physically implant the impurities. The implanted impurities are activated through annealing. However, if the annealing time exceeds several seconds, the implanted impurities may diffuse deeper due to the heat, resulting in a junction depth that is deeper than required, hindering the formation of a good device.

[0003] Therefore, flash lamp annealing (FLA) has recently attracted attention as an annealing technology for heating semiconductor wafers in an extremely short period of time. Flash lamp annealing uses a xenon flash lamp (hereinafter referred to as a "flash lamp"). Flash lamp annealing is a heat treatment technology that uses a xenon flash lamp (hereinafter referred to as a "flash lamp") to illuminate the front surface of a semiconductor wafer, thereby heating only the front surface of the semiconductor wafer, which has been implanted with impurities, for an extremely short period of time (less than a few milliseconds).

[0004] Xenon flash lamps emit light with a spectral distribution ranging from the ultraviolet to the near-infrared region, with shorter wavelengths than conventional halogen lamps, roughly aligning with the fundamental absorption band of silicon semiconductor wafers. Therefore, when a xenon flash lamp illuminates a semiconductor wafer, less light is transmitted, allowing the wafer to heat up rapidly. Furthermore, it has been shown that extremely short flash exposure times, under a few milliseconds, can selectively increase the temperature near the front surface of the semiconductor wafer. Therefore, the extremely short heating time of a xenon flash lamp prevents deep diffusion of impurities and allows for targeted activation.

[0005] In heat treatment equipment using a flash lamp, a flash lamp typically irradiates a semiconductor wafer while it is held on a pedestal. Because the flash lamp instantaneously applies extremely high-energy flash light to the front surface of the semiconductor wafer, the temperature of the front surface of the semiconductor wafer rises rapidly in an instant, while the temperature of the back surface does not rise much. Consequently, rapid thermal expansion occurs only on the front surface of the semiconductor wafer, causing the upper surface of the semiconductor wafer to bulge and warp. Furthermore, the next instant, the reaction causes the lower surface of the semiconductor wafer to bulge and warp. As a result, the pedestal supporting the semiconductor wafer may vibrate violently, causing the semiconductor wafer to jump from the pedestal, or even break the semiconductor wafer or the pedestal's support pins due to further collisions.

[0006] Therefore, in order to prevent the support pins from being broken due to the pressing force from the semiconductor wafer, a semiconductor wafer support system has been developed as disclosed in Patent Document 1 or Patent Document 2.

[0007] Specifically, Patent Documents 1 and 2 propose a support system that supports the workpiece while allowing the movement of the workpiece caused by heat (the movement of the outer end area and the central area in the vertical direction relative to each other).

[0008] [Background Art Literature]

[0009] [Patent Document]

[0010] [Patent Document 1] U.S. Patent No. 8,434,341

[0011] [Patent Document 2] U.S. Patent No. 9,627,244 Summary of the Invention

[0012] [Problems to be solved by the invention]

[0013] However, the techniques proposed in Patent Documents 1 and 2 use springs and actuators, for example, as components to allow for heat-induced movement of the workpiece. Such configurations complicate the structure of the devices proposed in Patent Documents 1 and 2. In particular, heat treatment devices using flash lamps assume high temperatures within the device, leading to concerns about component degradation or damage. Devices such as those proposed in Patent Documents 1 and 2 require greater attention to component management.

[0014] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a heat treatment susceptor and a heat treatment apparatus that have a simple structure and can prevent jumping and cracking of a substrate during flash irradiation.

[0015] [Technical means to solve the problem]

[0016] In order to solve the above-mentioned problem, the invention of technical solution 1 is characterized in that a base for heat treatment is provided for holding the substrate when the substrate is heat-treated by irradiating the substrate with a flash from a flash lamp, comprising: a holding plate having a planar holding surface; and a plurality of substrate support bodies erected on the holding surface; and a gap is formed around the erecting position of at least one of the substrate support bodies on the holding plate, and the gap has at least one curved portion or corner portion.

[0017] Furthermore, according to the heat treatment susceptor described in claim 1, the invention according to claim 2 is characterized in that the shape of the slit is a U-shape or a V-shape with an opening portion facing the center of the holding plate.

[0018] In addition, according to the heat treatment base described in Technical Solution 1, the invention of Technical Solution 3 is characterized in that the multiple substrate support bodies are upright on the first circumference and on the second circumference having a diameter larger than the diameter of the first circumference, and the U-shaped or V-shaped gap with the opening portion facing the center portion of the retaining plate is formed around the upright position of the substrate support body on the first circumference, and the U-shaped or V-shaped gap with the opening portion facing the end portion of the retaining plate is formed around the upright position of the substrate support body on the second circumference.

[0019] In addition, according to the heat treatment base described in Technical Solution 1, the invention of Technical Solution 4 is characterized in that the multiple substrate supports are upright on the first circumference and on the second circumference having a diameter larger than the diameter of the first circumference, so as to form the gap in a manner of surrounding a pair of substrate supports consisting of one substrate support upright on the first circumference and one substrate support upright on the second circumference.

[0020] Furthermore, according to the heat treatment susceptor according to any one of claims 1 to 3, the invention according to claim 5 is characterized in that the slits are formed around all the standing positions of the plurality of substrate supporting bodies.

[0021] In addition, according to the heat treatment base described in any one of technical solutions 1 to 5, the invention of technical solution 6 is characterized in that when the substrate is deformed by the flash irradiation from the flash lamp, the maximum deflection of the part surrounded by the gap caused by the pressing of the substrate through the substrate support body is less than the standing height of the substrate support body.

[0022] In addition, according to the heat treatment base described in any one of technical solutions 1 to 6, the invention of technical solution 7 is characterized in that when the substrate is deformed by the flash irradiation from the flash lamp, the upright position of the substrate support body surrounded by the gap is bent in a rotational manner.

[0023] In addition, the invention of Technical Solution 8 is characterized in that a heat treatment device for heating a substrate by irradiating a flash on the substrate comprises: a chamber for accommodating the substrate; a heat treatment base described in any one of Technical Solutions 1 to 7, which is arranged inside the chamber; and a flash lamp for irradiating the flash on the substrate held on the heat treatment base.

[0024] [Effects of the Invention]

[0025] According to the inventions of claim 1, 2, 6, 7, or 8, a slit is formed around the upright position of the substrate support, and the slit has at least one curved portion or corner. Therefore, even if the load on the substrate support increases due to deformation of the substrate during flash irradiation, the load is absorbed by the deflection of the portion surrounded by the slit. This simplifies the structure and prevents jumping and cracking of the substrate during flash irradiation.

[0026] According to the invention of technical solution 3, since the opening parts of the gap formed around the standing position of the substrate support body on the first circumference and the gap formed around the standing position of the substrate support body on the second circumference have different directions, it is possible to cope with the load on the substrate support body from substrates corresponding to each diameter.

[0027] According to the invention of technical solution 4, since the gap is formed in a manner of surrounding a pair of substrate supports consisting of a substrate support body erected on the first circumference and a substrate support body erected on the second circumference, the number of gaps can be reduced and the jumping and cracking of the substrate during flash irradiation can be effectively prevented.

[0028] According to the invention of claim 5, gaps are formed around all of the positions where the multiple substrate supports are positioned. Therefore, even if deformation of the substrate is uneven, the deflection of the portion surrounded by the gaps around each substrate support can be made different. Consequently, even if different loads are applied to each substrate support, the loads are appropriately absorbed. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a longitudinal sectional view showing the structure of the heat treatment apparatus of the present invention.

[0030] Figure 2 It is a perspective view showing the overall appearance of the holding portion.

[0031] Figure 3 This is a top view of the base.

[0032] Figure 4 Yes Figure 3 Cross-sectional view of section AA.

[0033] Figure 5 It is a top view of the transfer mechanism.

[0034] Figure 6 It is a side view of the transfer mechanism.

[0035] Figure 7 It is a plan view showing the arrangement of a plurality of halogen lamps HL.

[0036] Figure 8 1 and 2 are explanatory diagrams showing a semiconductor wafer W held on a susceptor and a holding plate when being irradiated with a flash light.

[0037] Figure 9 It will Figure 8 A partially enlarged view showing the substrate support pins and gaps.

[0038] Figure 10 It is a top view of the base according to the second embodiment.

[0039] Figure 11 It is a top view of the base according to the third embodiment.

[0040] Figure 12 It is a top view of the base in the fourth embodiment.

[0041] Figure 13 It is a top view of the base in the fifth embodiment.

[0042] Figure 14 It is a top view of the base in the sixth embodiment.

[0043] Figure 15 It is an explanatory diagram showing the shape of the slit of another example. DETAILED DESCRIPTION

[0044] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0045] <First embodiment>

[0046] Figure 1: is a longitudinal sectional view showing the structure of the heat treatment apparatus 1 of the present invention. The heat treatment apparatus 1 of the present embodiment is a flash lamp annealing apparatus that heats a semiconductor wafer W in the shape of a circular plate as a substrate by flash irradiating the semiconductor wafer W. The size of the semiconductor wafer W to be processed is not particularly limited, and is, for example, φ300mm or φ450mm. Impurities are pre-implanted into the semiconductor wafer W before being transported into the heat treatment apparatus 1, and activation treatment of the injected impurities is performed by the heating treatment of the heat treatment apparatus 1. In addition, Figure 1 In the drawings and the subsequent drawings, the size or number of each component is exaggerated or simplified as necessary to facilitate understanding.

[0047] Heat treatment apparatus 1 includes a chamber 6 for accommodating semiconductor wafers W, a flash heating unit 5 containing multiple flash lamps FL, and a halogen heating unit 4 containing multiple halogen lamps HL. The flash heating unit 5 is located above chamber 6, while the halogen heating unit 4 is located below. Heat treatment apparatus 1 also includes a holding unit 7 within chamber 6 for holding semiconductor wafers W in a horizontal position, and a transfer mechanism 10 for transferring semiconductor wafers W between holding unit 7 and the outside of the apparatus. Heat treatment apparatus 1 also includes a control unit 3 that controls the various operating mechanisms within halogen heating unit 4, flash heating unit 5, and chamber 6 to perform heat treatment on semiconductor wafers W.

[0048] 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 generally cylindrical shape with openings at the top and bottom. An upper chamber window 63 is attached to the upper opening and sealed, while a lower chamber window 64 is attached to the lower opening and sealed. The upper chamber window 63, forming the top of the chamber 6, is a disc-shaped member made of quartz and functions as a quartz window that allows the flash light emitted from the flash heater 5 to pass through the chamber 6. Furthermore, the lower chamber window 64, forming the floor of the chamber 6, is also a disc-shaped member made of quartz and functions as a quartz window that allows the light from the halogen heater 4 to pass through the chamber 6.

[0049] Furthermore, a reflection ring 68 is mounted on the upper portion of the inner wall of the chamber side portion 61, and a reflection ring 69 is mounted on the lower portion. Both reflection rings 68 and 69 are annular. The upper reflection ring 68 is mounted by inserting it from the upper side of the chamber side portion 61. On the other hand, the lower reflection ring 69 is mounted by inserting it from the lower side of the chamber side portion 61 and fixing it with screws (not shown). In other words, both reflection rings 68 and 69 are removably mounted on the chamber side portion 61. The inner space of the chamber 6, that is, the space surrounded by the upper chamber window 63, the lower chamber window 64, the chamber side portion 61, and the reflection rings 68 and 69, is defined as the heat treatment space 65.

[0050] By attaching the reflection rings 68 and 69 to the chamber side portion 61, a recess 62 is formed on the inner wall surface of the chamber 6. Specifically, the recess 62 is surrounded by the central portion of the inner wall surface of the chamber side portion 61 where the reflection rings 68 and 69 are not attached, 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 horizontal annular shape on the inner wall surface of the chamber 6, surrounding the holding portion 7 that holds the semiconductor wafer W.

[0051] The chamber side portion 61 and the reflection rings 68 and 69 are formed of a metal material (such as stainless steel) having excellent strength and heat resistance. In addition, the inner peripheral surfaces of the reflection rings 68 and 69 are mirror-finished by electrolytic nickel plating.

[0052] Furthermore, a transfer opening (furnace port) 66 for loading and unloading semiconductor wafers W into and out of the chamber 6 is formed on the chamber side 61. The transfer opening 66 can be opened and closed by a gate valve 162. The transfer opening 66 is connected to the outer peripheral surface of the recess 62. Therefore, when the gate valve 162 opens the transfer opening 66, the semiconductor wafer W can be loaded into and unloaded from the heat treatment space 65 through the recess 62 from the transfer opening 66. Furthermore, when the gate valve 162 closes the transfer opening 66, the heat treatment space 65 within the chamber 6 becomes a sealed space.

[0053] Furthermore, a radiation thermometer 20 is mounted in a portion of the outer wall of the chamber side portion 61 where a through-hole 61a is located. The through-hole 61a is a cylindrical hole designed to guide infrared light emitted from the lower surface of a semiconductor wafer W held on a susceptor 74 (described later) to the radiation thermometer 20. The through-hole 61a is tilted relative to the horizontal so that its axis intersects the main surface of the semiconductor wafer W held on the susceptor 74. A transparent window 21 made of barium fluoride is mounted at the end of the through-hole 61a adjacent to the heat treatment space 65. This window transmits infrared light within the wavelength range measurable by the radiation thermometer 20.

[0054] In addition, a gas supply hole 81 is formed on the upper part of the inner wall of the chamber 6 for supplying a processing gas (nitrogen (N2) in this embodiment) to the heat treatment space 65. The gas supply hole 81 is provided at a position above the recess 62, and may also be provided on the reflection ring 68. The gas supply hole 81 is connected to the 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 nitrogen supply source 85. In addition, a valve 84 is inserted midway along the path of the gas supply pipe 83. When the valve 84 is opened, nitrogen is supplied from the nitrogen supply source 85 to the buffer space 82. The nitrogen flowing into the buffer space 82 flows in a manner that diffuses in the buffer space 82 where the fluid resistance is smaller than that of the gas supply hole 81, and is supplied from the gas supply hole 81 to the heat treatment space 65. In addition, the processing gas is not limited to nitrogen, but can also be an inert gas such as argon (Ar) and helium (He), or a reactive gas such as oxygen (O2), hydrogen (H2), chlorine (Cl2), hydrogen chloride (HCl), ozone (O3), and ammonia (NH3).

[0055] On the other hand, a gas exhaust hole 86 for exhausting the gas in the heat treatment space 65 is formed at the lower part of the inner wall of the chamber 6. The gas exhaust hole 86 is formed at a position below the recess 62, and can also be provided in the reflection ring 69. The gas exhaust hole 86 is connected to the 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 the exhaust part 190. In addition, a valve 89 is inserted in the middle of the path of the gas exhaust pipe 88. When the valve 89 is opened, the gas in the heat treatment space 65 is discharged from the gas exhaust hole 86 through the buffer space 87 to the gas exhaust pipe 88. In addition, the gas supply hole 81 and the gas exhaust hole 86 can be provided in multiple numbers along the circumference of the chamber 6, or can be in the form of a slit. In addition, the nitrogen supply source 85 and the exhaust part 190 can be a mechanism provided in the heat treatment apparatus 1, or can be a public facility in the factory where the heat treatment apparatus 1 is installed.

[0056] Furthermore, a gas exhaust pipe 191 for exhausting the gas in the heat treatment space 65 is also connected to the front end of the transfer opening 66. The gas exhaust pipe 191 is connected to the 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.

[0057] Figure 2 This is a perspective view showing the overall appearance of the holding portion 7. The holding portion 7 comprises a base ring 71, a connecting portion 72, and a base 74. The base ring 71, the connecting portion 72, and the base 74 are all made of quartz. In other words, the entire holding portion 7 is made of quartz.

[0058] The base ring 71 is a quartz component with a circular arc shape and a portion missing from the circular ring. The missing portion is provided to prevent interference between the transfer arm 11 of the transfer mechanism 10 described later and the base ring 71. The base ring 71 is supported on the wall surface of the chamber 6 (see FIG. 1 ) by being placed on the bottom surface of the recess 62. Figure 1 On the upper surface of the base ring 71, a plurality of connecting portions 72 (in this embodiment, four at 90° intervals) are provided along the circumference of the annular shape. The connecting portions 72 are also made of quartz and are fixed to the base ring 71 by welding.

[0059] The base 74 is supported by four connecting portions 72 provided on the base ring 71 . Figure 3 74 is a top view of the base. Figure 4 Yes Figure 3 The susceptor 74 is a cross-sectional view taken along the AA line of FIG. 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 formed of quartz. The diameter of the holding plate 75 is larger than the diameter of the semiconductor wafer W. In other words, the holding plate 75 has a planar dimension larger than that of the semiconductor wafer W.

[0060] A guide ring 76 is provided on the peripheral edge of the upper surface of the retaining plate 75. The guide ring 76 is a circular ring-shaped component having an inner diameter larger than the diameter of the semiconductor wafer W. For example, when 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 is configured as a tapered surface that expands upward 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 welded to the upper surface of the retaining plate 75 or fixed to the retaining plate 75 by a separately processed pin or the like. Alternatively, the retaining plate 75 and the guide ring 76 can be processed as an integral component.

[0061] The area on the upper surface of the holding plate 75, inward from the guide ring 76, serves as a planar holding surface 75a for holding the semiconductor wafer W. Multiple substrate support pins 77 are erected on the holding surface 75a of the holding plate 75. In this embodiment, a total of twelve substrate support pins 77 are erected at 30° intervals along a circle concentric with the outer circumference of the holding surface 75a. The diameter of the circle containing the twelve substrate support pins 77 (the distance between opposing substrate support pins 77) is smaller than the diameter of the semiconductor wafer W. For a semiconductor wafer W with a diameter of 300 mm, the diameter is preferably 270 mm to 280 mm (280 mm in this embodiment). Each substrate support pin 77 is formed of quartz. The multiple substrate support pins 77 can be attached to the upper surface of the holding plate 75 by welding or can be integrally formed with the holding plate 75. The height of the substrate support pins 77 is 0.8 mm to 2 mm, preferably 0.8 mm to 1.2 mm.

[0062] like Figure 2As shown, the four connecting portions 72 erected on the base ring 71 are fixed to the peripheral edge of the retaining plate 75 of the base 74 by welding. In other words, the base 74 and the base ring 71 are fixedly connected via the connecting portions 72. The retaining unit 7 is installed in the chamber 6 by supporting the base ring 71 of the retaining unit 7 against the wall of the chamber 6. When the retaining unit 7 is installed in the chamber 6, the retaining plate 75 of the base 74 is in a horizontal position (with its normal aligned with the vertical direction). In other words, the retaining surface 75a of the retaining plate 75 is horizontal.

[0063] The semiconductor wafer W loaded into the chamber 6 is placed and held in a horizontal position on a susceptor 74 attached to the holding portion 7 of the chamber 6. At this time, the semiconductor wafer W is supported by point contact with the susceptor 74 by twelve substrate support pins 77 erected on the holding plate 75. More strictly speaking, the upper ends of the twelve substrate support pins 77 make point contact with the lower surface of the semiconductor wafer W, thereby supporting the semiconductor wafer W. Because the height 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) is uniform, the twelve substrate support pins 77 support the semiconductor wafer W in a horizontal position. Furthermore, the semiconductor wafer W is supported by the plurality of substrate support pins 77 at predetermined intervals from the holding surface 75a of the holding plate 75.

[0064] like Figures 2 to 4 As shown, a plurality of slits 78 are formed in the holding plate 75 of the base 74. Each slit 78 is located around the upright position of the substrate support pin 77. In this embodiment, slits 78 are formed around all the upright positions of each substrate support pin 77. In other words, slits 78 are formed around all the upright positions of the 12 substrate support pins 77. The slit 78 has a curved portion 78t. In this embodiment, the shape of the slit 78 is a U-shape with the opening portion facing the center of the holding plate 75. That is, as Figure 3 As shown, the end portion 78e faces the center of the holding plate 75, and the curved portion 78t faces the end of the holding plate 75. Each slit 78 is a notch that passes through the holding plate 75 vertically. Each slit 78 is formed so that the substrate support pin 77 is located inside the U shape.

[0065] Furthermore, the holding plate 75 of the base 74 is provided with four through holes 79 ( Figure 2 ). In addition, a portion for receiving the radiation thermometer 20 (refer to Figure 1 ) An opening (not shown) for transmitting radiation (infrared light) from the lower surface of the semiconductor wafer W held on the susceptor 74. The radiation thermometer 20 receives the infrared light emitted from the lower surface of the semiconductor wafer W held on the susceptor 74 and measures the temperature of the semiconductor wafer W.

[0066] Figure 5 : is a top view of the transfer mechanism 10. In addition, Figure 6 1 is a side view of the transfer mechanism 10. The transfer mechanism 10 includes two transfer arms 11. The transfer arms 11 are formed in an arc shape substantially along the annular recess 62. Two lifting pins 12 are provided on each transfer arm 11. Each transfer arm 11 can be rotated by a horizontal movement mechanism 13. The horizontal movement mechanism 13 enables a pair of transfer arms 11 to be moved to a position ( Figure 5 The solid line position), and the retreat position ( Figure 5 The horizontal moving mechanism 13 may be a mechanism that rotates each transfer arm 11 separately by a separate motor, or a mechanism that uses a link mechanism and rotates a pair of transfer arms 11 in conjunction with each other by a single motor.

[0067] Furthermore, the pair of transfer arms 11 are moved up and down together with the horizontal moving 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 lifting pins 12 are inserted through the through holes 79 (refer to FIG. Figure 2 and Figure 3 ), the upper end of the lifting pin 12 protrudes from the upper surface of the base 74. On the other hand, the lifting mechanism 14 lowers the pair of transfer arms 11 to the transfer action position, and pulls out the lifting pin 12 from the through hole 79. If the horizontal moving mechanism 13 moves in a manner to open the pair of transfer arms 11, then each transfer arm 11 moves to the retreat position. The retreat position of the pair of transfer arms 11 is directly above the base ring 71 of the retaining portion 7. Since the base ring 71 is placed on the bottom surface of the recess 62, the retreat position of the transfer arm 11 becomes the inner side of the recess 62. In addition, an exhaust mechanism (not shown) is also provided near the portion where the drive portion (horizontal moving mechanism 13 and lifting mechanism 14) of the transfer mechanism 10 is provided, and is constructed in a manner to discharge the ambient gas around the drive portion of the transfer mechanism 10 to the outside of the chamber 6.

[0068] Return to Figure 1The flash heating unit 5 disposed above the chamber 6 is constructed such that, inside a housing 51, it includes a light source including a plurality of (30 in this embodiment) xenon flash lamps FL and a reflector 52 disposed so as to cover the upper portion of the light source. Furthermore, a light irradiation window 53 is mounted on the bottom of the housing 51 of the flash heating unit 5. The light irradiation window 53 constituting the floor portion of the flash heating unit 5 is a plate-shaped quartz window formed of quartz. By disposing the flash heating unit 5 above the chamber 6, the light irradiation window 53 faces the upper chamber window 63. The flash lamp FL irradiates the heat treatment space 65 with flash light from above the chamber 6 through the light irradiation window 53 and the upper chamber window 63.

[0069] The flash lamps FL are long cylindrical rod-shaped lamps arranged in a plane with their longitudinal directions parallel to each other along the main surface (i.e., horizontally) of the semiconductor wafer W held by the holder 7. Therefore, the plane formed by the arrangement of the flash lamps FL is also a horizontal plane.

[0070] A xenon flash lamp FL consists of a rod-shaped glass tube (discharge tube) filled with xenon gas. Its ends are equipped with an anode and cathode connected to a capacitor, and a trigger electrode is attached to the outer circumference of the glass tube. Because xenon gas is an electrical insulator, even if charge accumulates in the capacitor, no electricity normally flows through the glass tube. However, when a high voltage is applied to the trigger electrode, breaking the insulation, the electricity accumulated in the capacitor instantly flows into the glass tube, exciting xenon atoms or molecules at this time and emitting light. This xenon flash lamp FL converts the static energy previously accumulated in the capacitor into extremely short light pulses of 0.1 to 100 milliseconds, resulting in extremely intense light output compared to continuously lit light sources like halogen lamps HL. In other words, the flash lamp FL emits light in a pulsed manner, emitting light for extremely short periods of less than a second. Furthermore, the flash lamp FL's emission duration can be adjusted by adjusting the coil constant of the lamp power supply that powers the flash lamp FL.

[0071] Furthermore, a reflector 52 is provided above the plurality of flash lamps FL so as to cover them entirely. The basic function of the reflector 52 is to reflect the flash light emitted from the plurality of flash lamps FL toward the heat treatment space 65. The reflector 52 is formed from an aluminum alloy plate, and its surface (the surface adjacent to the flash lamps FL) is roughened by blasting.

[0072] The halogen heating unit 4, located below the chamber 6, has a plurality (40 in this embodiment) of halogen lamps HL built into the inner side of a housing 41. The halogen heating unit 4 is a light irradiation unit that heats the semiconductor wafer W by irradiating the heat treatment space 65 with light from below the chamber 6 through the lower chamber window 64 using the plurality of halogen lamps HL.

[0073] Figure 7It is a top view showing the configuration of multiple halogen lamps HL. 40 halogen lamps HL are divided into two layers, upper and lower. 20 halogen lamps HL are arranged in the upper layer close to the holding part 7, and 20 halogen lamps HL are also arranged in the lower layer farther away from the holding part 7 than the upper layer. Each halogen lamp HL is a rod-shaped lamp with a long cylindrical shape. The 20 halogen lamps HL in both the upper and lower layers are arranged in parallel with each other along the main surface of the semiconductor wafer W held in the holding part 7 (that is, in the horizontal direction) with their respective long sides. As a result, the planes formed by the arrangement of the halogen lamps HL in the upper and lower layers are both horizontal planes.

[0074] In addition, if Figure 7 As shown, the density of the halogen lamps HL in both the upper and lower layers is higher in the area facing the periphery of the semiconductor wafer W held by the holder 7 than in the area facing the center. In other words, in both the upper and lower layers, the spacing between the halogen lamps HL in the periphery is shorter than in the center of the arrangement. Therefore, when heating with light from the halogen heating unit 4, a greater amount of light can be irradiated to the periphery of the semiconductor wafer W, where the temperature is more likely to drop.

[0075] Furthermore, the lamp group comprising the upper halogen lamps HL and the lamp group comprising the lower halogen lamps HL are arranged in a cross-matrix pattern. In other words, a total of 40 halogen lamps HL are arranged so that the longitudinal directions of the 20 halogen lamps HL arranged in the upper layer and the longitudinal directions of the 20 halogen lamps HL arranged in the lower layer are perpendicular to each other.

[0076] A halogen lamp HL is a filament-type light source that emits light by applying electricity to a filament housed inside a glass tube, causing it to incandescent. Inside the glass tube, a gas containing a trace amount of a halogen element (such as iodine or bromine) is introduced into an inert gas such as nitrogen or argon. The introduction of the halogen element prevents filament breakage and maintains a high filament temperature. Consequently, the halogen lamp HL has a longer lifespan than a typical incandescent lamp and can continuously emit strong light. In other words, the halogen lamp HL is a continuously lit lamp that emits light for at least one second. Furthermore, because the halogen lamp HL is a rod-shaped lamp, it has a long lifespan. By arranging the halogen lamp HL horizontally, the radiation efficiency toward the semiconductor wafer W above is excellent.

[0077] Furthermore, a reflector 43 ( Figure 1 The reflector 43 reflects the light emitted from the plurality of halogen lamps HL toward the heat treatment space 65 .

[0078] The control unit 3 controls the various operating mechanisms provided in the heat treatment apparatus 1. The hardware configuration of the control unit 3 is similar to that of a typical computer. Specifically, the control unit 3 includes a CPU (Central Processing Unit), which is a circuit that performs various computations; a ROM (Read Only Memory), which is a read-only memory that stores basic programs; a RAM (Random Access Memory), which is a readable and writable memory that stores various information; and a magnetic disk that stores control software and pre-stored data. The heat treatment apparatus 1 performs its processing as the CPU of the control unit 3 executes a specific processing program.

[0079] In order to prevent excessive temperature increases in the halogen heating unit 4, flash heating unit 5, and chamber 6 caused by the heat energy generated by the halogen lamp HL and flash lamp FL during heat treatment of semiconductor wafers W, the heat treatment apparatus 1 includes various cooling mechanisms in addition to the aforementioned configuration. For example, water cooling pipes (not shown) are installed in the walls of the chamber 6. Furthermore, the halogen heating unit 4 and flash heating unit 5 employ an air-cooling structure that creates an internal gas flow to dissipate heat. Furthermore, air is supplied to the gap between the upper chamber window 63 and the lamp radiation window 53 to cool the flash heating unit 5 and the upper chamber window 63.

[0080] Next, the processing sequence for semiconductor wafer W in heat treatment apparatus 1 will be described. Here, semiconductor wafer W, the target of processing, is a semiconductor substrate to which impurities (ions) have been added by ion implantation. These impurities are activated by flash irradiation heating (annealing) in heat treatment apparatus 1. The processing sequence in heat treatment apparatus 1 described below is performed by control of the various operating mechanisms of heat treatment apparatus 1 by control unit 3.

[0081] First, the gas supply valve 84 is opened, and the exhaust valves 89 and 192 are opened to start supplying and exhausting the interior of the chamber 6. When the valve 84 is opened, nitrogen gas is supplied from the gas supply hole 81 to the heat treatment space 65. Furthermore, when the valve 89 is opened, the gas in the chamber 6 is exhausted from the gas exhaust 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 exhausted from the lower portion of the heat treatment space 65.

[0082] Furthermore, by opening valve 192, the gas in chamber 6 is also exhausted from transfer opening 66. Furthermore, by using an exhaust mechanism (not shown), the ambient gas around the drive unit of transfer mechanism 10 is also exhausted. Furthermore, while heat treatment apparatus 1 is heat treating semiconductor wafers W, nitrogen gas is continuously supplied to heat treatment space 65, and the supply rate is appropriately changed depending on the treatment step.

[0083] Next, gate valve 162 opens, opening transfer opening 66. A transfer robot outside the apparatus then transfers the ion-implanted semiconductor wafer W through transfer opening 66 into heat treatment space 65 within chamber 6. The semiconductor wafer W, brought in and out by the transfer robot, stops directly above holding portion 7. Furthermore, the pair of transfer arms 11 of transfer mechanism 10 horizontally move from their retracted positions to their transfer operation positions and then rise. As a result, lift pins 12 protrude from the upper surface of holding plate 75 of base 74 through through-holes 79, receiving semiconductor wafer W. At this point, lift pins 12 rise above the upper ends of substrate support pins 77.

[0084] After the semiconductor wafer W is placed on the lifting pins 12, the transport robot withdraws from the heat treatment space 65 and closes the transport opening 66 through the gate valve 162. Then, a pair of transfer arms 11 descends to transfer the semiconductor wafer W from the transfer mechanism 10 to the base 74 of the holding portion 7, and is held in a horizontal position from below. The semiconductor wafer W is supported by a plurality of substrate support pins 77 erected on the holding plate 75 and held on the base 74. In addition, the semiconductor wafer W is held in the holding portion 7 with the front side, on which the pattern is formed and impurities are injected, as the upper surface. A specific gap is formed between the back side (the main surface on the opposite side to the front side) 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 that have descended to the bottom of the base 74 retreat to a retreat position, that is, to the inner side of the recess 62, through the horizontal moving mechanism 13.

[0085] After the semiconductor wafer W is held horizontally from below by the base 74 of the holding portion 7, the 40 halogen lamps HL of the halogen heating portion 4 are simultaneously lit to begin preliminary heating (auxiliary heating). The halogen light emitted from the halogen lamps HL passes through the lower chamber window 64 and the base 74 formed of quartz and irradiates the back of the semiconductor wafer W. By receiving the light irradiation from the halogen lamps HL, the semiconductor wafer W is preheated and the temperature rises. In addition, since the transfer arm 11 of the transfer mechanism 10 retreats to the inside of the recess 62, it does not become an obstacle to the heating of the halogen lamps HL.

[0086] When the halogen lamp HL is preheated, the temperature of the semiconductor wafer W is measured by the radiation thermometer 20. That is, the radiation thermometer 20 receives infrared light emitted from the back surface of the semiconductor wafer W held on the base 74 and measures the temperature of the wafer 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 lamp HL while monitoring whether the temperature of the semiconductor wafer W heated by the light irradiation from the halogen lamp HL reaches a specific preheating temperature T1. That is, the control unit 3 feedback-controls the output of the halogen lamp HL based on the measured value of the radiation thermometer 20 so that the temperature of the semiconductor wafer W reaches the preheating temperature T1. The preheating temperature T1 is set to about 200°C to 800°C, preferably about 350°C to 600°C (600°C in this embodiment) so that there is no concern about the diffusion of impurities added to the semiconductor wafer W due to heat.

[0087] 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 radiation thermometer 20 reaches the preheating temperature T1, the control unit 3 adjusts the output of the halogen lamp HL to maintain the temperature of the semiconductor wafer W approximately at the preheating temperature T1.

[0088] By performing this preliminary heating with the halogen lamps HL, the entire semiconductor wafer W is uniformly heated to the preliminary heating temperature T1. During the preliminary heating stage with the halogen lamps HL, the temperature of the peripheral portion of the semiconductor wafer W, where heat dissipation is more likely to occur, tends to be lower than that of the central portion. However, the density of the halogen lamps HL in the halogen heating unit 4 is higher in the area facing the peripheral portion than in the area facing the central portion of the semiconductor wafer W. Therefore, the amount of light irradiated on the peripheral portion of the semiconductor wafer W, where heat dissipation is more likely to occur, increases, making the in-plane temperature distribution of the semiconductor wafer W uniform during the preliminary heating stage. Furthermore, since the inner circumference of the reflection ring 69 mounted on the chamber side 61 is mirrored, the amount of light reflected by the inner circumference of the reflection ring 69 toward the peripheral portion of the semiconductor wafer W increases, making the in-plane temperature distribution of the semiconductor wafer W more uniform during the preliminary heating stage.

[0089] After the temperature of the semiconductor wafer W reaches the preliminary heating temperature T1 due to the light irradiation from the halogen lamp HL and a specific time has passed, the flash lamp FL of the flash heating unit 5 flash-irradiates the front surface of the semiconductor wafer W. At this time, part of the flash light emitted from the flash lamp FL is directly directed into the chamber 6, while the other part is temporarily reflected by the reflector 52 and then directed into the chamber 6. The semiconductor wafer W is flash-heated by the irradiation of these flash lights.

[0090] Because flash heating is performed using flash irradiation from the flash lamp FL, the temperature of the front surface of the semiconductor wafer W can be rapidly increased. Specifically, the flash irradiation from the flash lamp FL is an extremely short and intense flash of approximately 0.1 to 100 milliseconds, converting electrostatic energy previously accumulated in a capacitor into an extremely short light pulse. Furthermore, the temperature of the front surface of the semiconductor wafer W, flash-heated by the flash irradiation from the flash lamp FL, instantly rises to a processing temperature T2 exceeding 1000°C. After the impurities injected into the semiconductor wafer W are activated, the front surface temperature rapidly drops. Thus, because the heat treatment apparatus 1 can rapidly increase and decrease the temperature of the front surface of the semiconductor wafer W, the thermal diffusion of the impurities injected into the semiconductor wafer W can be suppressed, thereby promoting impurity activation. Furthermore, because the time required for impurity activation is significantly shorter than the time required for their thermal diffusion, activation is achieved even in a short period of approximately 0.1 to 100 milliseconds, when diffusion does not occur.

[0091] However, the flash irradiation causes the front surface temperature of the semiconductor wafer W to instantly rise to a processing temperature T2 exceeding 1000°C. Meanwhile, the instantaneous back surface temperature does not rise much from the preheating temperature T1. In other words, a temperature difference instantly arises between the front and back surfaces of the semiconductor wafer W. As a result, rapid thermal expansion occurs only on the front surface of the semiconductor wafer W, while the back surface undergoes almost no thermal expansion. This causes the semiconductor wafer W to instantly warp with the front surface becoming convex. Then, at the next instant, heat is transferred from the front surface of the semiconductor wafer W to the back surface, and the reaction to the warping caused by the convex front surface causes the back surface to warp with a convex back surface. Subsequently, the semiconductor wafer W repeats this warping, with the front and back surfaces alternating between convex and convex, while vibrating.

[0092] Here, if the susceptor 74 is securely supported by the base ring 71 and the four connecting portions 72 without the gap 78 formed therein, as in the conventional method, if the semiconductor wafer W warps with its front surface becoming convex, the edge of the semiconductor wafer W will collide with the upper surface of the susceptor 74. Conversely, if the semiconductor wafer W warps with its back surface becoming convex, the center of the semiconductor wafer W will collide with the upper surface of the susceptor 74. As a result, there is a risk of the semiconductor wafer W jumping, the upper surface of the susceptor 74 being damaged, and in the worst case, the wafer cracking.

[0093] Therefore, in the heat treatment apparatus 1 of the present invention, a slit 78 is engraved in the holding plate 75 of the susceptor 74. In the first embodiment, the U-shaped slit 78 is formed so as to surround each of the twelve substrate supporting pins 77 of the holding plate 75.

[0094] Figure 8 1 is an explanatory diagram showing the semiconductor wafer W held on the base 74 and the holding plate 75 when the flash is irradiated. Figure 9 It will Figure 8 The enlarged view of the substrate support pins 77 and the slits 78 is shown. When the semiconductor wafer W warps with the front surface as a convex surface during flash irradiation, the substrate support pins 77 receive a pressing force toward the bottom of the semiconductor wafer W caused by the warping of the semiconductor wafer W. As a result, the upright portion of the substrate support pins 77 surrounded by the slits 78 is positioned in a manner that Figure 9 The semiconductor wafer W is bent so as to rotate in the direction of arrow B with point O as the center. As a result, the pressure acting on the semiconductor wafer W during flash irradiation can be alleviated, and the semiconductor wafer W can be prevented from jumping or cracking.

[0095] In addition, generally speaking, the semiconductor wafer W is a thin plate-shaped substrate (for example, the thickness is 0.775 mm when the diameter is 300 mm) obtained by thinly slicing a cylindrical single crystal silicon ingot. Therefore, the semiconductor wafer W processed in this embodiment is also formed by single crystal silicon. In addition, the semiconductor wafer W is a semiconductor wafer sliced ​​along a specific crystal orientation of the silicon ingot. Typically, three types of wafers with surface orientations of (100), (110), and (111) are used, but wafers with a (100) surface orientation are the most used. In this embodiment, the semiconductor wafer W to be processed is also a wafer of single crystal silicon with a surface orientation of (100).

[0096] When a flash is irradiated on a semiconductor wafer W with a (100) plane, the semiconductor wafer W warps in a manner extending in the <100> direction. In other words, the semiconductor wafer W warps convexly so that both ends of the diameter of the semiconductor wafer W along the <100> direction are at the lowermost or uppermost sides.

[0097] When the semiconductor wafer W held on the susceptor 74 is irradiated with a flash of light, as shown in FIG. Figure 8 and Figure 9 As shown by the dot-dash line, the semiconductor wafer W warps in one of two equivalent <100> directions. This causes uneven deformation of the semiconductor wafer W, due to the characteristics of the semiconductor wafer W's crystal structure. In this embodiment, slits 78 are formed around all upright positions of each substrate support pin 77. This allows the amount of deflection of the portion surrounded by the slits 78 around each substrate support pin 77 to vary. Consequently, even if different loads are applied to each substrate support pin 77, the loads are appropriately absorbed.

[0098] In addition, if Figure 9 As shown, when the semiconductor wafer W is deformed by flash irradiation, the maximum deflection T of the upright position of the substrate support pins 77 surrounded by the slits 78 is smaller than the height of the substrate support pins 77. Thus, even if the deformation of the semiconductor wafer W increases and the pressing force increases, the end of the semiconductor wafer W is prevented from contacting the holding plate 75.

[0099] As described above, in this embodiment, when the semiconductor wafer W warps with its front surface convex due to flash irradiation, the pressing portion of the holding plate 75 pressed by the semiconductor wafer W bends to follow the deformation of the semiconductor wafer W. The bending of the holding plate 75 alleviates the pressure acting on the semiconductor wafer W due to the flash irradiation, and as a result, the semiconductor wafer W can be prevented from jumping off the susceptor 74 and cracking during the flash irradiation.

[0100] After the flash heating treatment is completed, the halogen lamp HL goes out after a specific time. As a result, the semiconductor wafer W is rapidly cooled from the pre-heating temperature T1. The temperature of the semiconductor wafer W during cooling is measured by the radiation thermometer 20, and its measurement result is transmitted to the control unit 3. The control unit 3 monitors whether the temperature of the semiconductor wafer W has dropped to a specific temperature based on the measurement result of the radiation thermometer 20. In addition, after the temperature of the semiconductor wafer W drops below the specific temperature, the pair of transfer arms 11 of the transfer mechanism 10 moves horizontally from the retreat position to the transfer action position and rises again, thereby causing the lifting pins 12 to protrude from the upper surface of the base 74 and receive the heat-treated semiconductor wafer W from the base 74. Next, the transport opening 66 closed by the gate valve 162 is opened, and the semiconductor wafer W placed on the lifting pins 12 is moved out by the transport robot outside the device, and the heat treatment device 1 completes the heating treatment of the semiconductor wafer W.

[0101] In the first embodiment, when the semiconductor wafer W is deformed so that its front surface becomes convex due to flash irradiation from the flash lamp FL, slits 78 are formed around the upright positions of the substrate support pins 77, which serve as the pressing portions of the holding plate 75 pressed by the semiconductor wafer W. Thus, even if the load on the substrate support pins 77 increases due to deformation of the substrate during flash irradiation, the load on the substrate support pins 77 is absorbed by the deflection of the portions surrounded by the slits 78.

[0102] Furthermore, it is believed that during flash irradiation, the semiconductor wafer W extends in two <100> directions, mutually orthogonal to the in-plane of the semiconductor wafer W. Furthermore, these four locations, totaling four, have the potential to press against the semiconductor wafer W during flash irradiation. Consequently, slits 78 are formed at the pressing locations of the retaining plate 75, where the semiconductor wafer W is believed to be pressed with particularly great force during flash irradiation. In particular, in this embodiment, slits 78 are formed around all of the twelve upright positions of the substrate support pins 77. Therefore, even if the semiconductor wafer W deforms due to flash irradiation, extending in one of the two <100> directions, and even if the deformation of the semiconductor wafer W is uneven, the pressing locations of the retaining plate 75 (the locations surrounded by slits 78) can flex to follow the deformation of the individual semiconductor wafers W. This simple configuration, with the provision of slits 78, mitigates the pressure acting on the semiconductor wafer W, preventing the semiconductor wafer W from bouncing or cracking.

[0103] <Second embodiment>

[0104] Next, a second embodiment of the present invention will be described. The overall structure of the heat treatment apparatus and the processing procedure for the semiconductor wafer W in the second embodiment are the same as those in the first embodiment. The second embodiment differs from the first embodiment in the structure of the susceptor.

[0105] Figure 10 It is a top view of the base 274 of the second embodiment. Figure 10 , the same reference numerals are given to the same elements as those in the first embodiment. The base 274 of the second embodiment includes a holding plate 275 and a plurality of substrate support pins 77. In the holding plate 275, a plurality of slits 278 are formed to replace the slits 78 of the first embodiment. In this embodiment, as in the case of the slits 78 of the first embodiment, slits 278 are formed around all the upright positions of the substrate support pins 77. In this embodiment, the shape of the slits 278 is a U-shape with the opening portion facing the end of the holding plate 275. That is, as Figure 10 As shown, the end portion 278 e faces the end of the retaining plate 275 , and the curved portion 278 t faces the center of the retaining plate 275 .

[0106] In the second embodiment, when the semiconductor wafer W is deformed so that its front surface becomes convex due to flash irradiation from the flash lamp FL, slits 278 are formed around the upright positions of the substrate support pins 77, which serve as the pressing areas of the holding plate 275 pressed by the semiconductor wafer W. Furthermore, as in the first embodiment, slits 278 are also formed around the pressing areas of the holding plate 275, which are believed to be pressed with particularly great force by the semiconductor wafer W during flash irradiation. Slits 278 are formed around all of the upright positions of the twelve substrate support pins 77. Therefore, even if the semiconductor wafer W is deformed in one of the two <100> directions due to flash irradiation, and even if the deformation of the semiconductor wafer W is uneven, the pressing areas of the holding plate 275 (areas surrounded by slits 278) can flex to follow the deformation of the individual semiconductor wafers W. This mitigates the pressure acting on the semiconductor wafer W, preventing the semiconductor wafer W from bouncing or cracking.

[0107] <Third embodiment>

[0108] Next, a third embodiment of the present invention will be described. The overall structure of the heat treatment apparatus and the processing procedure for semiconductor wafers W in the third embodiment are the same as those in the first embodiment. The third embodiment differs from the first embodiment in the structure of the susceptor.

[0109] Figure 11 It is a top view of the base 374 of the third embodiment. Figure 11Components identical to those in the first embodiment are denoted by the same reference numerals. The base 374 of the third embodiment includes a retaining plate 375 and a plurality of substrate support pins 377. The plurality of substrate support pins 377 are disposed upright on the first circumference C1 and the second circumference C2. The diameter of the second circumference C2 is greater than the diameter of the first circumference. Furthermore, the first circumference C1 and the second circumference C2 are substantially concentric circles. The diameters of the first circumference C1 and the second circumference C2 are smaller than the diameter of the semiconductor wafer W.

[0110] The first circumference C1 and the outer periphery of the holding surface of the holding plate 375 are roughly concentric circles. In addition, on the first circumference C1, a total of 12 substrate support pins 377a are erected at intervals of 30°. Slits 378a are formed around all the erected positions of the 12 substrate support pins 377a. The slits 378a have a curved portion. In this embodiment, the shape of the slit 378a is a U-shape with the opening portion facing the center of the holding plate 375. That is, as Figure 11 As shown, the end portion is toward the center portion of the retaining plate 375 , and the curved portion is toward the end portion of the retaining plate 375 .

[0111] In addition, the second circumference C2 is also roughly concentric with the outer circumference of the holding surface of the holding plate 375. In addition, on the second circumference C2, a total of 12 substrate support pins 377b are erected every 30°. Slits 378b are formed around all the erected positions of the 12 substrate support pins 377b. The slits 378b have a curved portion. In this embodiment, the shape of the slit 378b is a U-shape with the opening portion facing the end of the holding plate 375. That is, as Figure 11 As shown, the end portion is toward the end of the retaining plate 375, and the curved portion is toward the center portion of the retaining plate 375.

[0112] In the third embodiment, when the semiconductor wafer W is deformed so that its front surface becomes convex due to flash irradiation from the flash lamp FL, slits 378 are formed around the upright positions of the substrate support pins 377, which are the pressing areas of the holding plate 375 pressed by the semiconductor wafer W. Furthermore, as in the first embodiment, slits 378a or 378b are also formed at the pressing areas of the holding plate 375 that are believed to be pressed with particularly great force by the semiconductor wafer W during flash irradiation. Furthermore, slits 378a are formed around all upright positions of the twelve substrate support pins 377a on the first circumference C1, and slits 378b are formed around all upright positions of the twelve substrate support pins 377b on the second circumference C2. Therefore, even if the semiconductor wafer W is deformed by flash irradiation so as to extend in one of the two <100> directions, and even if the deformation of the semiconductor wafer W is uneven, the pressing portions of the retaining plate 375 (the portion surrounded by the slit 378 a and the portion surrounded by the slit 378 b ) can bend to follow the deformation of the semiconductor wafer W. This can alleviate the pressure acting on the semiconductor wafer W, preventing the semiconductor wafer W from jumping or cracking.

[0113] <Fourth embodiment>

[0114] Next, a fourth embodiment of the present invention will be described. The overall structure of the heat treatment apparatus and the processing procedure for semiconductor wafers W in the fourth embodiment are the same as those in the third embodiment. The fourth embodiment differs from the third embodiment in the structure of the susceptor.

[0115] Figure 12 It is a top view of the base 474 of the fourth embodiment. Figure 12 Components identical to those in the third embodiment are denoted by the same reference numerals. Also in the fourth embodiment, a plurality of substrate supporting pins 377 are erected on the first circumference C1 and the second circumference C2.

[0116] Slits 478a are formed around all the positions of the 12 substrate support pins 377a erected on the first circumference C1. The slits 478a also have a curved portion. In this embodiment, the shape of the slits 478a is a U-shape with the opening portion facing the end of the holding plate 475. In other words, Figure 12 As shown, the end portion is toward the end portion of the retaining plate 475 and the curved portion is toward the center portion of the retaining plate 475 .

[0117] Similarly, slits 478b are formed around all the positions of the 12 substrate support pins 377b erected on the second circumference C2. The slits 478b have a curved portion. In this embodiment, the shape of the slits 478b is a U-shape with the opening portion facing the center of the holding plate 475. In other words, Figure 12As shown, the end portion is toward the center portion of the retaining plate 475 , and the curved portion is toward the end portion of the retaining plate 475 .

[0118] In the fourth embodiment, when the semiconductor wafer W is deformed so that its front surface becomes convex due to flash irradiation from the flash lamp FL, slits 478 are formed around the upright positions of the substrate support pins 377, which are the pressing areas of the holding plate 475 pressed by the semiconductor wafer W. Furthermore, as in the third embodiment, slits 478a or 478b are also formed at the pressing areas of the holding plate 475 that are believed to be pressed with particularly great force by the semiconductor wafer W during flash irradiation. Furthermore, slits 478a are formed around all upright positions of the twelve substrate support pins 377a on the first circumference C1, and slits 478b are formed around all upright positions of the twelve substrate support pins 377b on the second circumference C2. Therefore, even if the semiconductor wafer W is deformed by flash irradiation so as to extend in one of the two <100> directions, and even if the deformation of the semiconductor wafer W is uneven, the pressing portions of the retaining plate 475 (the portion surrounded by the slit 478 a and the portion surrounded by the slit 478 b ) can bend to follow the deformation of the semiconductor wafer W. This can alleviate the pressure acting on the semiconductor wafer W, preventing the semiconductor wafer W from jumping or cracking.

[0119] <Fifth embodiment>

[0120] Next, a fifth embodiment of the present invention will be described. The overall structure of the heat treatment apparatus and the processing procedure for semiconductor wafers W in the fifth embodiment are the same as those in the third embodiment. The fifth embodiment differs from the third embodiment in the structure of the susceptor.

[0121] Figure 13 It is a top view of the base 574 of the fifth embodiment. Figure 13 Components identical to those in the third embodiment are denoted by the same reference numerals. In the fifth embodiment, a plurality of substrate support pins 577 are also provided on the first circumference C1 and the second circumference C2. A plurality of substrate support pins 577a are provided on the first circumference C1, and a plurality of substrate support pins 577b are provided on the second circumference C2.

[0122] In the retaining plate 575 of the present embodiment, a gap 578 is formed in a manner that surrounds a pair of substrate support pins 577s consisting of a substrate support pin 577a and a substrate support pin 577b. In addition, the substrate support pin 577a erected on the first circumference C1 and the substrate support pin 577b erected on the second circumference C2 are arranged on the same diameter D. Since the substrate support pins 577a and 577b erected on different circumferences are arranged on the same diameter D, the space required to form the gap 578 can be saved. The shape of the gap 578 is a U-shape with the opening portion facing the center of the retaining plate 575. That is, as Figure 13 As shown, the end portion is toward the center portion of the retaining plate 575, and the curved portion is toward the end portion of the retaining plate 575.

[0123] Furthermore, in this embodiment, the slits 578 are not formed around all of the upright positions of the substrate support pins 577a or 577b. Instead, the slits 578 are formed alternately around adjacent pairs of substrate support pins 577s. This reduces the number of slits. Furthermore, it is preferable that the slits 578 be formed particularly along lines along the <100> direction of the semiconductor wafer W. As described above, this is because the semiconductor wafer W is believed to be particularly susceptible to deformation in the <100> direction.

[0124] In the fifth embodiment, when the semiconductor wafer W is deformed so that its front surface becomes convex due to flash irradiation from the flash lamp FL, slits 578 are formed around the upright positions of the substrate support pins 577, which serve as the pressing areas of the holding plate 575 pressed by the semiconductor wafer W. Furthermore, as in the third embodiment, slits 578 are formed at the pressing areas of the holding plate 575, which are believed to be pressed with particularly great force by the semiconductor wafer W during flash irradiation. Furthermore, while slits 578 are not formed around all upright positions of the substrate support pins 577a and 577b, in this embodiment, the pressing areas of the holding plate 575 (areas surrounded by slits 578) can also flex to follow the deformation of the semiconductor wafer W. This mitigates the pressure acting on the semiconductor wafer W, preventing the semiconductor wafer W from bouncing or cracking.

[0125] <Sixth embodiment>

[0126] Next, a sixth embodiment of the present invention will be described. The overall structure of the heat treatment apparatus and the processing procedure for the semiconductor wafer W in the sixth embodiment are the same as those in the first embodiment. The sixth embodiment differs from the first embodiment in the structure of the susceptor.

[0127] Figure 14 It is a top view of the base 674 of the sixth embodiment. Figure 14Components identical to those in the first embodiment are denoted by the same reference numerals. The base 674 of the sixth embodiment includes a retaining plate 675 and a plurality of substrate support pins 77. A plurality of slits 678 are formed in the retaining plate 675, replacing the slits 78 of the first embodiment. In this embodiment, similar to the slits 78 of the first embodiment, slits 678 are formed around all upright positions of each substrate support pin 77. In this embodiment, the slits 678 are shaped like a spiral. It is believed that in a U-shaped configuration, when the portion surrounded by the slits 78 bends, the load is concentrated on the opening portion. On the other hand, it is believed that in a spiral configuration, when the portion surrounded by the slits 78 bends, the entire area surrounding the substrate support pins bends, making it less likely that the load will be concentrated on one portion. Therefore, it is expected that the retaining plate 675 will have a longer life.

[0128] In the sixth embodiment, when the semiconductor wafer W is deformed so that its front surface becomes convex due to flash irradiation from the flash lamp FL, slits 678 are formed around the upright positions of the substrate support pins 77, which serve as the pressing areas of the holding plate 675 pressed by the semiconductor wafer W. Furthermore, as in the first embodiment, slits 678 are also formed around the pressing areas of the holding plate 275, which are believed to be pressed with particularly great force by the semiconductor wafer W during flash irradiation. Slits 678 are formed around all of the upright positions of the twelve substrate support pins 77. Therefore, even if the semiconductor wafer W is deformed in one of the two <100> directions due to flash irradiation, and even if the deformation of the semiconductor wafer W is uneven, the pressing areas of the holding plate 675 (areas surrounded by slits 678) can flex to follow the deformation of the individual semiconductor wafers W. This mitigates the pressure acting on the semiconductor wafer W, preventing the semiconductor wafer W from bouncing or cracking.

[0129] <Other>

[0130] Figure 15 778 is an explanatory diagram showing the shape of another example of the slit 778. Figure 15 As shown, the slit 778 has a corner portion 778t instead of a curved portion. In other words, the shape of the slit 778 is a V-shape instead of a U-shape.

[0131] In the first to fourth and sixth embodiments, slits 78, 278, 378, 478, and 678 are formed around all upright positions of the substrate support pins 77 and 377, but the present invention is not limited thereto. As long as the slits 78, 278, 378, 478, and 678 are formed around at least one substrate support pin 77, they can alleviate the pressure acting on the semiconductor wafer W and prevent the semiconductor wafer W from jumping or cracking.

[0132] In the third and fourth embodiments, the substrate support pins 377a provided on the first circumference C1 and the substrate support pins 377b provided on the second circumference C2 are arranged on the same diameter in the drawings, but this is not limiting. As in the fifth embodiment, the substrate support pins 377a provided on the first circumference C1 and the substrate support pins 377b provided on the second circumference C2 may also be arranged on the same diameter.

[0133] The shape of the slit is not limited to that described in the first to sixth embodiments. Any slit having at least one curved portion or corner is sufficient. Specifically, the slit can be formed in the retaining plate 75 such that the portion of the retaining plate 75 pressed by the semiconductor wafer W bends when the semiconductor wafer W is deformed by the flashlight from the flash lamp FL. By forming the slit in advance, the portion of the retaining plate 75 pressing against the semiconductor wafer W bends to follow the deformation of the semiconductor wafer W, thereby alleviating the pressure on the semiconductor wafer W and preventing it from bouncing or cracking.

[0134] Furthermore, in the above embodiment, the flash heating unit 5 includes 30 flash lamps FL, but this is not limited to this. The number of flash lamps FL can be any number. Furthermore, the flash lamps FL are not limited to xenon flash lamps and can also 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.

[0135] Furthermore, the substrates processed by the heat treatment apparatus of the present invention are not limited to semiconductor wafers, but may also be glass substrates used in flat panel displays such as liquid crystal displays or solar cell substrates. Furthermore, the technology of the present invention can also be applied to the heat treatment of high-k dielectric gate insulating films (High-k films), the bonding of metals to silicon, or the crystallization of polycrystalline silicon.

[0136] [Explanation of symbols]

[0137] 1: Heat treatment device

[0138] 3: Control Department

[0139] 4: Halogen heating unit

[0140] 5: Flash heating unit

[0141] 6: Chamber

[0142] 7: Maintaining part

[0143] 10: Transfer mechanism

[0144] 11: Transfer arm

[0145] 12: Lifting pin

[0146] 13: Horizontal movement mechanism

[0147] 14: Lifting mechanism

[0148] 20: Radiation thermometer

[0149] 21:Through the Window

[0150] 41: Shell

[0151] 43:Reflector

[0152] 51: Shell

[0153] 52:Reflector

[0154] 53: Light radiation window

[0155] 61: Chamber side

[0156] 62: concave part

[0157] 63: Upper chamber window

[0158] 64: Lower chamber window

[0159] 65: Heat treatment space

[0160] 66:Transportation opening

[0161] 68,69: Reflection ring

[0162] 71: Abutment ring

[0163] 72: Connection

[0164] 74,274,374,474,574,674: base

[0165] 75,275,375,475,575,675: Keep plate

[0166] 75a: Keep the surface

[0167] 76: Guide ring

[0168] 77,377,377a,377b,577,577a,577b: Substrate support pins

[0169] 78,278,378,378a,378b,478,478a,478b,578,678,778: Gap

[0170] 78e,278e: end

[0171] 78t,278t: Qubu

[0172] 79:Through hole

[0173] 81: Gas supply hole

[0174] 82,87: buffer space

[0175] 83: Gas supply pipe

[0176] 84,89,192: valve

[0177] 85: Nitrogen supply source

[0178] 86: Gas exhaust hole

[0179] 88:Gas exhaust pipe

[0180] 162: Gate Valve

[0181] 190: Exhaust

[0182] 191:Gas exhaust pipe

[0183] 577s: substrate support pin pair

[0184] 778t: Corner

[0185] B: Arrow

[0186] C1: 1st circle

[0187] C2: 2nd circle

[0188] D: Diagonal

[0189] T: Maximum deflection

[0190] T1: Preheating temperature

[0191] T2: Processing temperature

[0192] W: Semiconductor wafer.

Claims

1. A susceptor for heat treatment, characterized in that: The method includes: holding the substrate while performing heat treatment on the substrate by irradiating the substrate with flash light from a flash lamp; a retaining plate having a planar retaining surface; and A plurality of substrate supports are vertically arranged on the holding surface; and A gap is formed around at least one of the substrate support positions on the holding plate, The gap has a curved portion or a corner portion surrounding at least one of the substrate supports, The slit is a notch that passes through the retaining plate from top to bottom.

2. The heat treatment susceptor according to claim 1, characterized in that The slit has a U-shape or a V-shape with an opening facing the center of the holding plate.

3. The heat treatment susceptor according to claim 1, characterized in that The plurality of substrate supports are erected on a first circumference and a second circumference having a diameter larger than that of the first circumference. The U-shaped or V-shaped slit is formed around the standing position of the substrate support on the first circumference, with the opening facing the center of the holding plate. The U-shaped or V-shaped slit is formed around the upright position of the substrate support on the second circumference, with its opening facing the end of the holding plate.

4. The heat treatment susceptor according to claim 1, characterized in that The plurality of substrate supports are erected on a first circumference and a second circumference having a diameter larger than that of the first circumference. The gap is formed so as to surround a pair of substrate supports consisting of one substrate support provided upright on the first circumference and one substrate support provided upright on the second circumference.

5. The heat treatment susceptor according to any one of claims 1 to 3, characterized in that The gap is formed around all the standing positions of the plurality of substrate supports.

6. The heat treatment susceptor according to any one of claims 1 to 4, characterized in that When the substrate is deformed by flash irradiation from the flash lamp, a maximum deflection of a portion surrounded by the slit caused by the substrate being pressed via the substrate support is smaller than a standing height of the substrate support.

7. The heat treatment susceptor according to any one of claims 1 to 4, characterized in that When the substrate is deformed by the flash irradiation from the flash lamp, the standing position of the substrate support body surrounded by the slit is bent so as to rotate.

8. A heat treatment device, characterized in that The substrate is heated by irradiating the substrate with a flash of light, comprising: a chamber for accommodating the substrate; The heat treatment susceptor according to any one of claims 1 to 4, arranged inside the chamber; and The flash lamp irradiates the substrate held on the heat treatment susceptor with the flash.

Images