Heat treatment susceptor and heat treatment device

Abstract

To provide a heat treatment susceptor and a heat treatment device with a simple configuration capable of preventing jumping and cracking of a substrate during flash light irradiation.SOLUTION: A heat treatment susceptor 74 is for holding a semiconductor wafer W when performing a heat treatment of the semiconductor wafer W by irradiating flash light from a flash lamp to a substrate. The heat treatment susceptor 74 includes a holding plate 75 having a flat holding surface 75a and a plurality of substrate support pins 77 erected on the holding surface 75a. A slit 78 is formed around the surroundings of a location where at least one of the substrate support pins 77 of the holding plate 75 is erected. The slit 78 has at least one curved portion 78t.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a heat treatment susceptor that holds a thin precision electronic substrate such as a semiconductor wafer (hereinafter simply referred to as a "substrate") when the substrate is heat-treated by irradiating the substrate with flash light from a flash lamp, and to a heat treatment apparatus equipped with the heat treatment susceptor. [Background technology]

[0002] In the semiconductor device manufacturing process, doping with impurities is an essential step for forming pn junctions within semiconductor wafers. Currently, doping with impurities is typically performed by ion implantation followed by annealing. Ion implantation is a technique in which impurity elements such as boron (B), arsenic (As), and phosphorus (P) are ionized and then bombarded with a semiconductor wafer at high acceleration voltages, physically implanting the impurities. The implanted impurities are activated by annealing. However, if the annealing time is longer than a few seconds, the implanted impurities may diffuse too deeply due to the heat, resulting in a junction depth that is deeper than required, which may hinder the formation of good devices.

[0003] Therefore, flash lamp annealing (FLA) has been attracting attention in recent years as an annealing technology that heats semiconductor wafers in an extremely short time.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 a semiconductor wafer into which impurities have been implanted in an extremely short time (a few milliseconds or less).

[0004] The spectral distribution of radiation from a xenon flash lamp ranges from the ultraviolet to near-infrared range, with a shorter wavelength than conventional halogen lamps and a wavelength that nearly coincides with 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 surface area of ​​the semiconductor wafer. Therefore, with an extremely short temperature rise using a xenon flash lamp, it is possible to activate the impurities without causing them to diffuse deeply.

[0005] In heat treatment equipment using flash lamps, a semiconductor wafer is typically held on a susceptor and irradiated with flash light from the flash lamp. Because the flash lamp instantaneously irradiates the front surface of the semiconductor wafer with extremely high-energy flash light, the surface temperature of the semiconductor wafer rises rapidly in an instant, while the back surface temperature does not rise as much. This causes sudden thermal expansion only on the front surface of the semiconductor wafer, causing the semiconductor wafer to warp, with the top surface convex. The next moment, the semiconductor wafer recoils and warps, with the bottom surface convex. As a result, the semiconductor wafer vibrates violently on the susceptor supporting it, causing the semiconductor wafer to jump off the susceptor, and even the impact can break the semiconductor wafer or the susceptor's support pins.

[0006] Therefore, in order to prevent support pins from cracking due to the pressing force from the semiconductor wafer, support systems for semiconductor wafers such as those disclosed in Patent Document 1 and Patent Document 2 have been developed.

[0007] Specifically, Patent Documents 1 and 2 propose a support system that supports a workpiece for interrelated vertical movement between the outer edge regions and the central region of the workpiece while allowing thermally induced workpiece movement (interrelated vertical movement between the outer edge regions and the central region of the workpiece). [Prior art documents] [Patent documents]

[0008] [Patent Document 1] U.S. Patent No. 8,434,341 [Patent Document 2] U.S. Patent No. 9,627,244 Summary of the Invention [Problem to be solved by the invention]

[0009] However, the technologies disclosed in Patent Documents 1 and 2 use, for example, springs, actuators, etc., as a configuration for allowing heat-induced movement of the workpiece. The technologies disclosed in Patent Documents 1 and 2, which have such a configuration, result in a complex device structure. In particular, in heat treatment devices using flash lamps, the inside of the device is expected to reach high temperatures, and deterioration or damage to parts due to high temperatures is also possible. Devices such as those disclosed in Patent Documents 1 and 2 require additional care in managing parts.

[0010] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a heat treatment susceptor and a heat treatment apparatus that have a simple configuration and can prevent a substrate from jumping or cracking when irradiated with flash light. [Means for solving the problem]

[0011] In order to solve the above problem, the invention of claim 1 provides a heat treatment susceptor for holding a substrate when the substrate is heat treated by irradiating the substrate with flash light from a flash lamp, the heat treatment susceptor comprising a holding plate having a flat holding surface and a plurality of substrate supports erected on the holding surface, wherein a slit is formed in the holding plate around the erected position of at least one of the substrate supports, and the slit has at least one curved portion or corner. The slit has a U-shape or a V-shape with its opening facing the center of the holding plate. It is characterized by:

[0013] Also, claims 2 The invention of A heat treatment susceptor for holding a substrate when heat treatment of the substrate is performed by irradiating the substrate with flash light from a flash lamp, the heat treatment susceptor comprising: a holding plate having a planar holding surface; and a plurality of substrate supports erected on the holding surface, wherein a slit is formed in the holding plate around the erected position of at least one of the substrate supports, the slit having at least one curved portion or corner; The plurality of substrate supports are erected on a first circumference and on a second circumference having a diameter larger than that of the first circumference, and the slits are U-shaped or V-shaped with their openings facing the center of the holding plate around the erected positions of the substrate supports on the first circumference, and the slits are U-shaped or V-shaped with their openings facing the edge of the holding plate around the erected positions of the substrate supports on the second circumference.

[0014] Also, claims 3 The invention of A heat treatment susceptor for holding a substrate when heat treatment of the substrate is performed by irradiating the substrate with flash light from a flash lamp, the heat treatment susceptor comprising: a holding plate having a planar holding surface; and a plurality of substrate supports erected on the holding surface, wherein a slit is formed in the holding plate around the erected position of at least one of the substrate supports, the slit having at least one curved portion or corner; The plurality of substrate supports are erected on a first circumference and on a second circumference having a diameter larger than that of the first circumference, and the slit is formed to surround a pair of substrate supports consisting of one of the substrate supports erected on the first circumference and one of the substrate supports erected on the second circumference.

[0015] Also, claims 4 The invention of A heat treatment susceptor for holding a substrate when heat treatment of the substrate is performed by irradiating the substrate with flash light from a flash lamp, the heat treatment susceptor comprising: a holding plate having a planar holding surface; and a plurality of substrate supports erected on the holding surface, wherein a slit is formed in the holding plate around the erected position of at least one of the substrate supports, the slit having at least one curved portion or corner; The slits are formed around all of the upright positions of the plurality of substrate supports.

[0016] Also, claims 5 The invention of A heat treatment susceptor for holding a substrate when heat treatment of the substrate is performed by irradiating the substrate with flash light from a flash lamp, the heat treatment susceptor comprising: a holding plate having a planar holding surface; and a plurality of substrate supports erected on the holding surface, wherein a slit is formed in the holding plate around the erected position of at least one of the substrate supports, the slit having at least one curved portion or corner; When the substrate is deformed by irradiation of flash light from the flash lamp, the maximum amount of deflection of the portion surrounded by the slit caused by the substrate being pressed through the substrate support is smaller than the erect height of the substrate support.

[0017] Also, claims 6 The invention of A heat treatment susceptor for holding a substrate when heat treatment of the substrate is performed by irradiating the substrate with flash light from a flash lamp, the heat treatment susceptor comprising: a holding plate having a planar holding surface; and a plurality of substrate supports erected on the holding surface, wherein a slit is formed in the holding plate around the erected position of at least one of the substrate supports, the slit having at least one curved portion or corner; When the substrate is deformed by irradiation of flash light from the flash lamp, the upright position of the substrate support surrounded by the slit is bent so as to rotate.

[0018] Also, claims7 The present invention is a heat treatment apparatus for heating a substrate by irradiating the substrate with flash light, the heat treatment apparatus comprising a chamber for accommodating the substrate, and a heat treatment device disposed inside the chamber, the heat treatment device comprising: a heat treatment device for heating the substrate by irradiating the substrate with flash light; 6 and a flash lamp that irradiates the substrate held by the heat treatment susceptor with the flash light. [Effects of the Invention]

[0019] Claims 1 to 7 According to the invention, a slit is formed around the upright position of the substrate support, and the slit has at least one curved or cornered portion. Therefore, even if the load on the substrate support increases due to deformation of the substrate when irradiated with flash light, the portion surrounded by the slit bends, thereby absorbing the load on the substrate support. Therefore, with a simple configuration, it is possible to prevent the substrate from jumping or cracking when irradiated with flash light.

[0020] Claim 2 According to the invention, the slits formed around the upright position of the substrate support on the first circumference and the slits formed around the upright position of the substrate support on the second circumference have different opening directions, so that they can accommodate the load from the substrate to the substrate support according to each diameter.

[0021] Claim 3 According to the invention, a slit is formed to surround a pair of substrate supports, each of which consists of one substrate support standing on a first circumference and one substrate support standing on a second circumference, thereby effectively preventing the substrate from jumping or cracking when irradiated with flash light while reducing the number of slits.

[0022] Claim 4According to the invention, slits are formed around the periphery of all of the upright positions of the multiple substrate supports. Therefore, even if the deformation of the substrate is uneven, the amount of deflection of the portion surrounded by the slits around each substrate support can be made different. As a result, even if different loads are applied to each substrate support, the loads can be absorbed appropriately. [Brief explanation of the drawings]

[0023] [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. 4 is a cross-sectional view showing the cross section AA in FIG. [Figure 5] FIG. [Figure 6] FIG. [Figure 7] FIG. 2 is a plan view showing the arrangement of a plurality of halogen lamps HL. [Figure 8] 10 is an explanatory diagram illustrating the behavior of a semiconductor wafer W held by a susceptor and a holding plate when irradiated with flash light. FIG. [Figure 9] 9 is a partially enlarged view showing the substrate support pins and slits in FIG. 8. FIG. [Figure 10] FIG. 10 is a plan view of a susceptor according to a second embodiment. [Figure 11] FIG. 10 is a plan view of a susceptor according to a third embodiment. [Figure 12] FIG. 10 is a plan view of a susceptor according to a fourth embodiment. [Figure 13] FIG. 10 is a plan view of a susceptor according to a fifth embodiment. [Figure 14] FIG. 10 is a plan view of a susceptor according to a sixth embodiment. [Figure 15] FIG. 10 is an explanatory diagram showing another example of the shape of the slit. DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0025] First Embodiment FIG. 1 is a longitudinal cross-sectional view showing the configuration of a heat treatment apparatus 1 according to the present invention. The heat treatment apparatus 1 of this embodiment 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 may be, for example, φ300 mm or φ450 mm. Impurities are implanted into the semiconductor wafer W before it is loaded into the heat treatment apparatus 1, and the implanted impurities are activated by the heat treatment performed by the heat treatment apparatus 1. 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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 the 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.

[0030] The chamber side portion 61 and the reflecting rings 68, 69 are made of a metal material (for example, stainless steel) that has excellent strength and heat resistance. The inner peripheral surfaces of the reflecting rings 68, 69 are made into a mirror finish by electrolytic nickel plating.

[0031] 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 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 transfer opening 66 and the recess 62. Furthermore, when the gate valve 162 closes the transfer opening 66, the heat treatment space 65 in the chamber 6 becomes an airtight space.

[0032] Furthermore, a radiation thermometer 20 is attached to a portion of the outer wall surface of the chamber side portion 61 where a through hole 61a is provided. The through hole 61a is a cylindrical hole for guiding infrared light emitted from the underside of a semiconductor wafer W held on a susceptor 74 (described later) to the radiation thermometer 20. The through hole 61a is provided at an angle with respect to the horizontal direction so that the axis of the through hole 61a intersects with the main surface of the semiconductor wafer W held on the susceptor 74. A transparent window 21 made of a barium fluoride material that transmits infrared light in a wavelength range that can be measured by the radiation thermometer 20 is attached to the end of the through hole 61a facing the heat treatment space 65.

[0033] Furthermore, gas supply holes 81 are formed in the upper part of the inner wall of the chamber 6 to supply a processing gas (nitrogen gas (N2) in this embodiment) to the heat treatment space 65. The gas supply holes 81 are formed at a position above the recessed portion 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 nitrogen gas supply source 85. A valve 84 is inserted in the gas supply pipe 83. When the valve 84 is opened, nitrogen gas is supplied from the nitrogen gas supply source 85 to the buffer space 82. The nitrogen 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 is not limited to nitrogen gas, but may be an inert gas such as argon (Ar) or helium (He), or a reactive gas such as oxygen (O2), hydrogen (H2), chlorine (Cl2), hydrogen chloride (HCl), ozone (O3), or ammonia (NH3).

[0034] 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, the gas in 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 nitrogen gas supply source 85 and the exhaust unit 190 may be mechanisms provided in the heat treatment apparatus 1 or may be utilities of the factory where the heat treatment apparatus 1 is installed.

[0035] 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.

[0036] 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.

[0037] 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, spaced at 90° intervals) 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.

[0038] 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 showing the AA section in FIG. 3. 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.

[0039] 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.

[0040] 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 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 (280 mm in this embodiment). Each substrate support pin 77 is made of quartz. The 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. The height of the substrate support pins 77 is 0.8 mm to 2 mm, preferably 0.8 mm to 1.2 mm.

[0041] 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 in a horizontal plane.

[0042] The semiconductor wafer W loaded 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 point contact with 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 make point contact with the underside of the semiconductor wafer W to support the semiconductor wafer W. Because the heights of the twelve substrate support pins 77 (the distances from the upper ends of the substrate support pins 77 to the holding surface 75a of the holding plate 75) are uniform, the semiconductor wafer W can be supported in a horizontal position by the twelve substrate support pins 77. Furthermore, the semiconductor wafer W is supported by the plurality of substrate support pins 77 at a predetermined distance from the holding surface 75a of the holding plate 75.

[0043] As shown in FIGS. 2 to 4 , a plurality of slits 78 are formed in the holding plate 75 of the susceptor 74. Each slit 78 is located around the upright position of a substrate support pin 77. In this embodiment, a slit 78 is formed around the upright position of each substrate support pin 77. In other words, a slit 78 is formed around the upright positions of all 12 substrate support pins 77. The slits 78 have a curved portion 78t. In this embodiment, the slits 78 are U-shaped with their openings facing the center of the holding plate 75. That is, as shown in FIG. 3 , the end 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 penetrates the holding plate 75 from top to bottom. Each slit 78 is formed so that the substrate support pin 77 is located inside the U-shape.

[0044] The holding plate 75 of the susceptor 74 is provided with four through holes 79 (FIG. 2) through which lift pins 12 of the transfer mechanism 10, which will be described later, penetrate to transfer the semiconductor wafer W. The holding plate 75 is also provided with an opening (not shown) through which a radiation thermometer 20 (see FIG. 1) receives radiation (infrared light) emitted from the bottom surface of the semiconductor wafer W held on the susceptor 74. The radiation thermometer 20 receives the infrared light emitted from the bottom surface of the semiconductor wafer W held on the susceptor 74 to measure the temperature of the semiconductor wafer W.

[0045] 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 upright on each transfer arm 11. 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 pair of transfer arms 11 transfer a semiconductor wafer W to the holder 7 and a retracted position (position indicated by a two-dot chain line in FIG. 5) where the pair of 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 a mechanism that rotates each transfer arm 11 using an individual motor, or a mechanism that rotates the pair of transfer arms 11 in conjunction with each other using a link mechanism using a single motor.

[0046] 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.

[0047] 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.

[0048] The multiple 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.

[0049] A xenon flash lamp FL comprises a rod-shaped 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 through 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 through 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 the coil constant of the lamp power supply that supplies power to the flash lamp FL.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] Next, the processing procedure for a semiconductor wafer W in the heat treatment apparatus 1 will be described. The semiconductor wafer W to be processed here is a semiconductor substrate to which impurities (ions) have been added by ion implantation. The impurities are activated by a flash light irradiation heat treatment (annealing) performed by the heat treatment apparatus 1. The processing procedure for the heat treatment apparatus 1, which will be described below, progresses as the control unit 3 controls each operating mechanism of the heat treatment apparatus 1.

[0060] 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.

[0061] 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.

[0062] Next, the gate valve 162 is opened to open the transfer opening 66, and the semiconductor wafer W after ion implantation is loaded into the heat treatment space 65 in the chamber 6 through the transfer opening 66 by a transfer robot external to the apparatus. The semiconductor wafer W loaded 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.

[0063] 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 162. 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 the surface on which the pattern has been formed and on which impurities have been implanted facing upward. 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.

[0064] After the semiconductor wafer W is held from below in a horizontal position by the susceptor 74 of the holder 7, the 40 halogen lamps HL of the halogen heating unit 4 are simultaneously turned on 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 made of quartz, and is irradiated onto the backside 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.

[0065] When preheating is performed using the halogen lamps HL, 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 backside of the semiconductor wafer W held on the susceptor 74 and measures 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 feedback-controls the output of the halogen lamps HL based on the value measured by the radiation thermometer 20 so that the temperature of the semiconductor wafer W becomes the preheating temperature T1. The preheating temperature T1 is set to approximately 200°C to 800°C, preferably approximately 350°C to 600°C (600°C in this embodiment), at which there is no risk of impurities added to the semiconductor wafer W being diffused by heat.

[0066] 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 lamps HL to maintain the temperature of the semiconductor wafer W at approximately the preheating temperature T1.

[0067] By performing preheating using the halogen lamps HL in this manner, the entire semiconductor wafer W is uniformly heated to the preheating temperature T1. During preheating using the halogen lamps HL, the temperature of the peripheral portion of the semiconductor wafer W, where heat dissipation is more likely, tends to be lower than that of the central portion. However, the halogen lamps HL are arranged more densely in the halogen heating unit 4 in the area facing the peripheral portion of the semiconductor wafer W than in the area facing the central portion of the semiconductor wafer W. This increases the amount of light irradiated onto the peripheral portion of the semiconductor wafer W, where heat dissipation is more likely, thereby achieving a more uniform in-plane temperature distribution of the semiconductor wafer W during the preheating stage. Furthermore, because the inner surface of the reflecting ring 69 attached to the chamber side 61 is a mirror, the amount of light reflected by the inner surface of this reflecting ring 69 toward the peripheral portion of the semiconductor wafer W increases, resulting in a more uniform in-plane temperature distribution of the semiconductor wafer W during the preheating stage.

[0068] When the temperature of the semiconductor wafer W reaches the preheating temperature T1 due to the light irradiation from the halogen lamps HL and a predetermined time has elapsed, the flash lamps FL of the flash heating unit 5 irradiate the surface of the semiconductor wafer W with flash light. At this time, part of the flash light emitted from the flash lamps FL is directed 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.

[0069] Flash heating is performed by irradiating a flash of light (flash of light) from the flash lamps FL, which can raise the surface temperature of the semiconductor wafer W in a short time. Specifically, 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 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, which is flash-heated by the flash of light irradiated from the flash lamps FL, instantaneously rises to a processing temperature T2 of 1000°C or higher. After the impurities implanted in the semiconductor wafer W are activated, the surface temperature rapidly drops. In this way, the heat treatment apparatus 1 can raise and lower the surface temperature of the semiconductor wafer W in an extremely short time, thereby activating the impurities implanted in the semiconductor wafer W while suppressing their thermal diffusion. Furthermore, because the time required for impurity activation is extremely short compared to the time required for thermal diffusion, activation can be completed even in a short time of approximately 0.1 to 100 milliseconds, which is short enough that diffusion does not occur.

[0070] By this flash light irradiation, the surface temperature of the semiconductor wafer W instantaneously rises to a processing temperature T2 of 1000°C or higher, while the backside temperature at that instant does not rise significantly above the preheating temperature T1. In other words, a temperature difference occurs instantaneously between the front and back sides of the semiconductor wafer W. As a result, rapid thermal expansion occurs only on the front side of the semiconductor wafer W, while the back side experiences almost no thermal expansion, causing the semiconductor wafer W to momentarily warp, making the front side convex. Subsequently, in the next instant, heat is conducted from the front side of the semiconductor wafer W to the back side, and the back side warps convexly in reaction to the warping that caused the front side to become convex. Thereafter, the semiconductor wafer W vibrates, repeatedly warping so that the front and back sides alternately become convex.

[0071] Here, in the case where the susceptor 74 without the slits 78 is firmly supported by the base ring 71 and the four connecting portions 72 as in the conventional case, when the semiconductor wafer W warps so that the front surface is convex, the edge of the semiconductor wafer W collides with the upper surface of the susceptor 74. Conversely, when the semiconductor wafer W warps so that the back surface is convex, the center of the semiconductor wafer W collides with the upper surface of the susceptor 74. As a result, there is a risk that the semiconductor wafer W may jump, the upper surface of the susceptor 74 may be scratched, or in the worst case, the wafer may crack.

[0072] Therefore, in the heat treatment apparatus 1 according to the present invention, slits 78 are formed in the holding plate 75 of the susceptor 74. In the first embodiment, U-shaped slits 78 are formed so as to surround each of the twelve substrate support pins 77 of the holding plate 75.

[0073] FIG. 8 is an explanatory diagram illustrating the behavior of the semiconductor wafer W and holding plate 75 held by the susceptor 74 during flash light irradiation. FIG. 9 is a partially enlarged view showing the substrate support pins 77 and slits 78 in FIG. 8. When the semiconductor wafer W warps so that its surface becomes convex during flash light irradiation, the warpage of the semiconductor wafer W presses the substrate support pins 77 downward on the semiconductor wafer W. As a result, the upright portions of the substrate support pins 77 surrounded by the slits 78 bend so as to rotate in the direction of arrow B around point O in FIG. 9. As a result, the stress acting on the semiconductor wafer W during flash light irradiation is alleviated, preventing the semiconductor wafer W from jumping or cracking.

[0074] Furthermore, a semiconductor wafer W is generally a thin plate-like substrate obtained by thinly slicing a cylindrical ingot of single crystal silicon (for example, a thickness of 0.775 mm for a diameter of 300 mm). Therefore, the semiconductor wafer W processed in this embodiment is also formed of single crystal silicon. The semiconductor wafer W is also sliced ​​along a specific crystal orientation of the silicon ingot. Typically, three types of wafers with plane orientations of (100), (110), and (111) are used, with those with a (100) plane orientation being the most commonly used. In this embodiment as well, the semiconductor wafer W to be processed is a single crystal silicon wafer with a plane orientation of (100).

[0075] When a semiconductor wafer W having a (100) surface orientation is irradiated with flash light, <100> The semiconductor wafer W is warped so as to stretch in the direction. <100> The semiconductor wafer W is warped in a convex shape so that both ends of the diameter along the direction are at the lowest or highest side.

[0076] When a semiconductor wafer W held on the susceptor 74 is irradiated with a flash of light, two equivalent <100> The semiconductor wafer W warps so as to stretch in one of the directions. As described above, it is thought that the deformation of the semiconductor wafer W becomes uneven due to the characteristics of the crystalline structure of the semiconductor wafer W. In this embodiment, slits 78 are formed around all of the upright positions of the substrate support pins 77. The amount of deflection of the portion surrounded by the slits 78 around each substrate support pin 77 can be made different. This allows the loads to be absorbed appropriately even if different loads are applied to each substrate support pin 77.

[0077] 9, when the semiconductor wafer W is deformed by irradiation with flash light, the maximum amount of deflection T of the upright positions of the substrate support pins 77 surrounded by the slits 78 is smaller than the height of the substrate support pins 77. This makes it possible to prevent the edge of the semiconductor wafer W from coming into contact with the holding plate 75 even if the amount of deformation of the semiconductor wafer W is large and the pressing force is large.

[0078] As described above, in this embodiment, when the semiconductor wafer W warps so that its surface becomes convex due to the irradiation of flash light, 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 relieves the stress acting on the semiconductor wafer W due to the irradiation of flash light, and as a result, it is possible to prevent the semiconductor wafer W from jumping off the susceptor 74 and cracking during the irradiation of flash light.

[0079] 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 radiation thermometer 20, and the measurement results are transmitted to the control unit 3. The control unit 3 monitors, based on the measurement results from the 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 162, is opened, and the semiconductor wafer W placed on the lift pins 12 is removed by a transfer robot external to the apparatus, completing the heat treatment of the semiconductor wafer W in the heat treatment apparatus 1.

[0080] In the first embodiment, when the semiconductor wafer W is deformed so that its surface becomes convex due to the irradiation of flash light from the flash lamps FL, slits 78 are formed around the upright positions of the substrate support pins 77, which serve as pressing portions of the holding plate 75 that are pressed by the semiconductor wafer W. As a result, even if the load on the substrate support pins 77 increases due to deformation of the substrate when irradiated with flash light, the portions surrounded by the slits 78 bend, and the load on the substrate support pins 77 is absorbed.

[0081] In addition, the semiconductor wafer W expands when irradiated with flash light. <100> It is considered that there are two directions perpendicular to each other within the plane of the semiconductor wafer W. A total of four positions on both ends of these positions have the potential to press the semiconductor wafer W when irradiated with flash light. Therefore, slits 78 are also formed in the pressing portions of the holding plate 75 that are considered to be pressed with a particularly large force by the semiconductor wafer W when irradiated with flash light. In particular, in this embodiment, slits 78 are formed around the peripheries of all the erect positions of the 12 substrate support pins 77. For this reason, it is considered that there are two directions perpendicular to each other within the plane of the semiconductor wafer W when irradiated with flash light. <100> Even if the semiconductor wafer W is deformed to stretch in either direction, or even if the deformation of the semiconductor wafer W is uneven, the pressing portion of the holding plate 75 (the portion surrounded by the slits 78) can bend to follow the respective deformations of the semiconductor wafer W. As a result, with the simple configuration of providing the slits 78, the stress acting on the semiconductor wafer W can be alleviated, and the semiconductor wafer W can be prevented from jumping or cracking.

[0082] Second Embodiment Next, a second embodiment of the present invention will be described. The overall configuration of the heat treatment apparatus and the processing procedure for semiconductor wafers W of the second embodiment are the same as those of the first embodiment. The second embodiment differs from the first embodiment in the configuration of the susceptor.

[0083] FIG. 10 is a plan view of a susceptor 274 of the second embodiment. In FIG. 10, the same elements as those in the first embodiment are denoted by the same reference numerals. The susceptor 274 of the second embodiment includes a holding plate 275 and a plurality of substrate support pins 77. The holding plate 275 has a plurality of slits 278 formed therein instead of the slits 78 in the first embodiment. In this embodiment, similar to the slits 78 in the first embodiment, slits 278 are formed around all of the upright positions of the substrate support pins 77. In this embodiment, the slits 278 are U-shaped with their openings facing the end of the holding plate 275. That is, as shown in FIG. 10, an end 278e faces the end of the holding plate 275, and a curved portion 278t faces the center of the holding plate 275.

[0084] In the second embodiment, too, slits 278 are formed around the upright positions of the substrate support pins 77 as pressing portions of the holding plate 275 that are pressed by the semiconductor wafer W when the semiconductor wafer W is deformed to have a convex surface by the irradiation of flash light from the flash lamps FL. As in the first embodiment, slits 278 are also formed in pressing portions of the holding plate 275 that are thought to be pressed with a particularly large force by the semiconductor wafer W when the flash light is irradiated. Slits 278 are formed around the upright positions of all 12 substrate support pins 77. For this reason, when the semiconductor wafer W is deformed to have a convex surface by the irradiation of flash light, the slits 278 are formed around the upright positions of all 12 substrate support pins 77. <100> Even if the semiconductor wafer W is deformed to stretch in either direction, or even if the deformation of the semiconductor wafer W is uneven, the pressing portion of the holding plate 275 (the portion surrounded by the slits 278) can bend to follow the respective deformations of the semiconductor wafer W. This can relieve the stress acting on the semiconductor wafer W and prevent the semiconductor wafer W from jumping or cracking.

[0085] <Third embodiment> Next, a third embodiment of the present invention will be described. The overall configuration of the heat treatment apparatus of the third embodiment and the processing procedure for the semiconductor wafer W are the same as those of the first embodiment. The third embodiment differs from the first embodiment in the configuration of the susceptor.

[0086] FIG. 11 is a plan view of a susceptor 374 of the third embodiment. In FIG. 11, the same elements as those in the first embodiment are denoted by the same reference numerals. The susceptor 374 of the third embodiment includes a holding plate 375 and a plurality of substrate support pins 377. The plurality of substrate support pins 377 are erected on a first circumference C1 and a second circumference C2. The diameter of the second circumference C2 is larger than the diameter of the first circumference. The first circumference C1 and the second circumference C2 are substantially concentric. The diameters of the first circumference C1 and the second circumference C2 are smaller than the diameter of the semiconductor wafer W.

[0087] The first circumference C1 is substantially concentric with the outer circumferential circle of the holding surface of the holding plate 375. A total of 12 substrate support pins 377a are erected on the first circumference C1, spaced apart at 30° intervals. Slits 378a are formed around the periphery of each of the 12 substrate support pins 377a. The slits 378a have curved portions. In this embodiment, the slits 378a are U-shaped with their openings facing the center of the holding plate 375. That is, as shown in FIG. 11 , the ends face the center of the holding plate 375, and the curved portions face the ends of the holding plate 375.

[0088] The second circumference C2 is also approximately concentric with the outer circumferential circle of the holding surface of the holding plate 375. A total of 12 substrate support pins 377b are erected on the second circumference C2, spaced apart at 30° intervals. Slits 378b are formed around the periphery of each of the 12 substrate support pins 377b. The slits 378b have curved portions. In this embodiment, the slits 378b are U-shaped with their openings facing the ends of the holding plate 375. That is, as shown in FIG. 11 , the ends face the ends of the holding plate 375, and the curved portions face the center of the holding plate 375.

[0089] In the third embodiment, too, slits 378 are formed around the upright positions of the substrate support pins 377, which serve as pressing portions of the holding plate 375 that are pressed by the semiconductor wafer W when the semiconductor wafer W is deformed to have a convex surface by the irradiation of flash light from the flash lamps FL. As in the first embodiment, slits 378a or 378b are also formed at pressing portions of the holding plate 375 that are thought to be pressed with a particularly large force by the semiconductor wafer W when the semiconductor wafer W is irradiated with flash light. Note that slits 378a are formed around the upright positions of all twelve substrate support pins 377a on the first circumference C1, and slits 378b are formed around the upright positions of all twelve substrate support pins 377b on the second circumference C2. For this reason, when flash light is irradiated, two semiconductor wafers W are formed. <100> Even if the semiconductor wafer W is deformed to stretch in either direction, or even if the deformation of the semiconductor wafer W is uneven, the pressing portions of the holding plate 375 (the portions surrounded by the slits 378a and the portions surrounded by the slits 378b) can bend to follow the respective deformations of the semiconductor wafer W. This relieves the stress acting on the semiconductor wafer W, thereby preventing the semiconductor wafer W from jumping or cracking.

[0090] <Fourth embodiment> Next, a fourth embodiment of the present invention will be described. The overall configuration of the heat treatment apparatus and the processing procedure for semiconductor wafers W of the fourth embodiment are the same as those of the third embodiment. The fourth embodiment differs from the third embodiment in the configuration of the susceptor.

[0091] Fig. 12 is a plan view of a susceptor 474 according to the fourth embodiment. In Fig. 12, the same elements as those in the third embodiment are denoted by the same reference numerals. In the fourth embodiment, a plurality of substrate support pins 377 are also provided upright on a first circumference C1 and a second circumference C2.

[0092] Slits 478a are formed around all of the twelve substrate support pins 377a standing on the first circumference C1. The slits 478a also have curved portions. In this embodiment, the slits 478a are U-shaped with their openings facing the ends of the holding plate 475. That is, as shown in FIG. 12 , the ends face the ends of the holding plate 475, and the curved portions face the center of the holding plate 475.

[0093] Similarly, slits 478b are formed around the periphery of each of the twelve substrate support pins 377b erected on the second circumference C2. The slits 478b have curved portions. In this embodiment, the slits 478b are U-shaped with their openings facing the center of the holding plate 475. That is, as shown in FIG. 12, the ends face the center of the holding plate 475, and the curved portions face the ends of the holding plate 475.

[0094] In the fourth embodiment, too, slits 478 are formed around the upright positions of the substrate support pins 377 as pressing portions of the holding plate 475 that are pressed by the semiconductor wafer W when the semiconductor wafer W is deformed to have a convex surface by the irradiation of flash light from the flash lamps FL. As in the third embodiment, slits 478a or 478b are also formed at pressing portions of the holding plate 475 that are thought to be pressed with a particularly large force by the semiconductor wafer W when the semiconductor wafer W is irradiated with flash light. Note that slits 478a are formed around the upright positions of all 12 substrate support pins 377a on the first circumference C1, and slits 478b are formed around the upright positions of all 12 substrate support pins 377b on the second circumference C2. For this reason, when flash light is irradiated, two semiconductor wafers W are formed. <100> Even if the semiconductor wafer W is deformed to stretch in either direction, or even if the deformation of the semiconductor wafer W is uneven, the pressing portions of the holding plate 475 (the portions surrounded by the slits 478a and the portions surrounded by the slits 478b) can bend to follow the respective deformations of the semiconductor wafer W. This can relieve the stress acting on the semiconductor wafer W and prevent the semiconductor wafer W from jumping or cracking.

[0095] Fifth Embodiment Next, a fifth embodiment of the present invention will be described. The overall configuration of the heat treatment apparatus and the processing procedure for the semiconductor wafer W of the fifth embodiment are the same as those of the third embodiment. The fifth embodiment differs from the third embodiment in the configuration of the susceptor.

[0096] Figure 13 is a plan view of a susceptor 574 of the fifth embodiment. In Figure 13, the same elements as 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 upright on a first circumference C1 and a second circumference C2. A plurality of substrate support pins 577a are provided upright on the first circumference C1, and a plurality of substrate support pins 577b are also provided upright on the second circumference C2.

[0097] In this embodiment, a slit 578 is formed in the holding plate 575 so as to surround a pair of substrate support pins 577s, each of which includes one substrate support pin 577a and one substrate support pin 577b. Furthermore, 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 for forming the slit 578 can be reduced. The slit 578 has a U-shape with its opening facing the center of the holding plate 575. That is, as shown in FIG. 13 , the end faces the center of the holding plate 575 and the curved portion faces the end of the holding plate 575.

[0098] In this embodiment, the slits 578 are not formed around the upright positions of all the substrate support pins 577a or 577b. The slits 578 are alternately formed around the adjacent pairs of substrate support pins 577s. This allows the number of slits to be reduced. The slits 578 are particularly suitable for the semiconductor wafer W. <100> As described above, the semiconductor wafer W is preferably formed on a line along the direction. <100> This is because it is thought that deformation is particularly likely in the direction.

[0099] In the fifth embodiment, too, slits 578 are formed around the upright positions of substrate support pins 577 as pressing portions of holding plate 575 that are pressed by semiconductor wafer W when the semiconductor wafer W is deformed to have a convex surface by the irradiation of flash light from flash lamps FL. As in the third embodiment, slits 578 are formed at pressing portions of holding plate 575 that are expected to be pressed with particularly large force by semiconductor wafer W when flash light is irradiated. Note that slits 578 are not formed around all of the upright positions of substrate support pins 577a, 577b. However, in this embodiment, too, the pressing portions of holding plate 575 (portions surrounded by slits 578) can bend to follow the deformation of semiconductor wafer W. This relieves stress acting on semiconductor wafer W and prevents the semiconductor wafer W from jumping or cracking.

[0100] Sixth Embodiment Next, a sixth embodiment of the present invention will be described. The overall configuration of the heat treatment apparatus of the sixth embodiment and the processing procedure for the semiconductor wafer W are the same as those of the first embodiment. The sixth embodiment differs from the first embodiment in the configuration of the susceptor.

[0101] FIG. 14 is a plan view of a susceptor 674 of the sixth embodiment. In FIG. 14, the same elements as those of the first embodiment are denoted by the same reference numerals. The susceptor 674 of the sixth embodiment includes a holding plate 675 and a plurality of substrate support pins 77. The holding plate 675 has a plurality of slits 678 formed therein instead of 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 of the upright positions of each substrate support pin 77. In this embodiment, the shape of the slits 678 is spiral. In a U-shape, when the portion surrounded by the slits 78 bends, it is thought that a load is concentrated at the opening. On the other hand, in a spiral shape, when the portion surrounded by the slits 78 bends, the entire periphery of the substrate support pin bends, so it is thought that a load is less likely to be concentrated at one portion. This is expected to extend the life of the holding plate 675.

[0102] In the sixth embodiment, too, slits 678 are formed around the upright positions of the substrate support pins 77 as pressing portions of the holding plate 675 that are pressed by the semiconductor wafer W when the semiconductor wafer W is deformed to have a convex surface by the irradiation of flash light from the flash lamps FL. As in the first embodiment, slits 678 are also formed in pressing portions of the holding plate 275 that are thought to be pressed with a particularly large force by the semiconductor wafer W when the flash light is irradiated. Slits 678 are formed around the upright positions of all 12 substrate support pins 77. For this reason, when the semiconductor wafer W is deformed to have a convex surface by the irradiation of flash light, the slits 678 are formed around the upright positions of all 12 substrate support pins 77. <100> Even if the semiconductor wafer W is deformed to stretch in either direction, or even if the deformation of the semiconductor wafer W is uneven, the pressing portion of the holding plate 675 (the portion surrounded by the slits 678) can bend to follow the respective deformations of the semiconductor wafer W. This can relieve the stress acting on the semiconductor wafer W and prevent the semiconductor wafer W from jumping or cracking.

[0103] <Other> Fig. 15 is an explanatory diagram showing the shape of another example of slit 778. As shown in Fig. 15, slit 778 has corners 778t instead of curved portions. That is, the shape of slit 778 is V-shaped instead of U-shaped.

[0104] In the first to fourth and sixth embodiments, the slits 78, 278, 378, 478, 678 are formed around all of the upright positions of the substrate support pins 77, 377, but this is not limiting. As long as the slits 78, 278, 378, 478, 678 are formed around at least one substrate support pin 77, stress acting on the semiconductor wafer W can be alleviated to prevent the semiconductor wafer W from jumping or cracking.

[0105] In the third and fourth embodiments, the substrate support pins 377a erected on the first circumference C1 and the substrate support pins 377b erected on the second circumference C2 are not arranged on the same diameter in the drawings, but this is not limiting. As in the fifth embodiment, the substrate support pins 377a erected on the first circumference C1 and the substrate support pins 377b erected on the second circumference C2 may be arranged on the same diameter.

[0106] The shape of the slit is not limited to the shapes of the slits in the first to sixth embodiments. The slit may have any shape as long as it has at least one curved or cornered portion. In other words, the slit may be formed in the holding plate 75 so that the pressing portion of the holding plate 75 pressed by the semiconductor wafer W will bend when the semiconductor wafer W is deformed by the irradiation of flash light from the flash lamps FL. By forming the slit in this manner, the pressing portion of the holding plate 75 will bend to follow the deformation of the semiconductor wafer W, thereby alleviating the stress acting on the semiconductor wafer W and preventing the semiconductor wafer W from jumping or cracking.

[0107] 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.

[0108] Furthermore, the substrates to be processed by the heat treatment apparatus according to the present invention are not limited to semiconductor wafers, but may also be glass substrates used in flat panel displays such as liquid crystal display devices, or substrates for solar cells. Furthermore, the technology according to the present invention may be applied to the heat treatment of high-dielectric-constant gate insulating films (High-k films), bonding between metal and silicon, or crystallization of polysilicon. [Explanation of symbols]

[0109] 1. Heat treatment equipment 3. Control Unit 4 Halogen heating section 5 Flash heating section 6 chambers 7 Holding part 10 Transfer mechanism 11 Transfer arm 12 lift pins 13 Horizontal movement mechanism 14 Lifting mechanism 20 Radiation thermometer 21 Transparent window 41 Case 43 Reflector 51 Case 52 Reflector 53 Lamp light emission window 61 Chamber side 62 recess 63 Upper chamber window 64 Lower chamber window 65 Heat Treatment Space 66 Transport opening 68,69 Reflective ring 71 Base Ring 72 Connecting part 74,274,374,474,574,674 susceptor 75,275,375,475,575,675 Retaining Plate 75a Holding surface 76 Guide Ring 77,377,377a,377b,577,577a,577b Board support pins 78,278,378,378a,378b,478,478a,478b,578,678,778 Slit 78e,278e end 78t,278t curved section 79 Through Hole 81 Gas supply hole 82,87 Buffer space 83 Gas supply pipe 84, 89, 192 valves 85 Nitrogen gas supply source 86 Gas exhaust vent 88 Gas Exhaust Pipe 162 Gate valve 190 Exhaust section 191 Gas exhaust pipe 577s PCB support pin pair 778t Corner B arrow C1 First Circumference C2 Second Circumference D diagonal T Maximum deflection T1 Preheating temperature T2 processing temperature W Semiconductor wafer

Claims

1. A heat treatment susceptor that holds a substrate when performing heat treatment on the substrate by irradiating the substrate with flash light from a flash lamp, comprising: a holding plate having a planar holding surface; a plurality of substrate supports erected on the holding surface, a slit is formed in the holding plate around the upright position of at least one of the substrate supports; the slit has at least one curved or cornered portion; The shape of the slit is U-shaped or V-shaped with an opening facing the center of the holding plate.

2. A heat treatment susceptor that holds a substrate when performing heat treatment on the substrate by irradiating the substrate with flash light from a flash lamp, comprising: a holding plate having a planar holding surface; a plurality of substrate supports erected on the holding surface, a slit is formed in the holding plate around the upright position of at least one of the substrate supports; the slit has at least one curved or cornered portion; the plurality of substrate supports are provided upright on a first circumference and on a second circumference having a diameter larger than that of the first circumference; a U-shaped or V-shaped slit having an opening facing a center of the holding plate is formed around the upright position of the substrate support on the first circumference; A susceptor for heat treatment, characterized in that a U-shaped or V-shaped slit is formed around the upright position of the substrate support on the second circumference, with the opening portion facing the end of the holding plate.

3. A heat treatment susceptor that holds a substrate when performing heat treatment on the substrate by irradiating the substrate with flash light from a flash lamp, comprising: a holding plate having a planar holding surface; a plurality of substrate supports erected on the holding surface, a slit is formed in the holding plate around the upright position of at least one of the substrate supports; the slit has at least one curved or cornered portion; 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; A susceptor for heat treatment, characterized in that the slit is formed to surround a pair of substrate supports consisting of one of the substrate supports standing on the first circumference and one of the substrate supports standing on the second circumference.

4. A heat treatment susceptor that holds a substrate when performing heat treatment on the substrate by irradiating the substrate with flash light from a flash lamp, comprising: a holding plate having a planar holding surface; a plurality of substrate supports erected on the holding surface, a slit is formed in the holding plate around the upright position of at least one of the substrate supports; the slit has at least one curved or cornered portion; A susceptor for heat treatment, wherein the slits are formed around all of the upright positions of the plurality of substrate supports.

5. A heat treatment susceptor that holds a substrate when performing heat treatment on the substrate by irradiating the substrate with flash light from a flash lamp, comprising: a holding plate having a planar holding surface; a plurality of substrate supports erected on the holding surface, a slit is formed in the holding plate around the upright position of at least one of the substrate supports; the slit has at least one curved or cornered portion; a heat treatment susceptor characterized in that, when the substrate is deformed by irradiation of flash light from the flash lamp, the maximum amount of deflection of the portion surrounded by the slit caused by the substrate being pressed through the substrate support is smaller than the erect height of the substrate support.

6. A heat treatment susceptor that holds a substrate when performing heat treatment on the substrate by irradiating the substrate with flash light from a flash lamp, comprising: a holding plate having a planar holding surface; a plurality of substrate supports erected on the holding surface, a slit is formed in the holding plate around the upright position of at least one of the substrate supports; the slit has at least one curved or cornered portion; When the substrate is deformed by irradiation of a flash light from the flash lamp, the substrate support surrounded by the slit bends so as to rotate.

7. 1. A heat treatment apparatus for heating a substrate by irradiating the substrate with flash light, comprising: a chamber for accommodating the substrate; a heat treatment susceptor according to any one of claims 1 to 6, which is disposed inside the chamber; a flash lamp that irradiates the substrate held by the heat treatment susceptor with the flash light; A heat treatment apparatus comprising:

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