Heat treatment equipment

Abstract

To provide a thermal treatment device capable of efficiently heating a substrate.SOLUTION: A flush heating part 5 comprising a plurality of flush lamps FL is provided on an upper side of a chamber 6 for housing a semiconductor wafer W is provided, and an auxiliary heating part 4 having a plurality of VCSELs (a vertical resonance type surface light emitting layer) 45 is provided on a lower side. After the semiconductor wafer W is pre-heated by a light irradiation from each VCSEL 45, the flush light is radiated to a front surface of the semiconductor wafer W from each flush lamp FL to momently increase a temperature of the front surface. Each VCSEL 45 can emit light of a relative high intensity as compared with an LED. Therefore, if the light is radiated from the plurality of VCSELs 45, the intensity of the light radiated to the semiconductor wafer W can be enhanced, and the semiconductor wafer W cna be efficiently heated.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a heat treatment apparatus that heats a substrate by irradiating the substrate with light. Substrates to be processed include, for example, semiconductor wafers, substrates for liquid crystal display devices, substrates for flat panel displays (FPDs), substrates for optical discs, substrates for magnetic discs, or substrates for solar cells.

Background Art

[0002] In the manufacturing process of semiconductor devices, flash lamp annealing (FLA) that heats a semiconductor wafer in an extremely short time has attracted attention. Flash lamp annealing is a heat treatment technique that irradiates flash light onto the surface of a semiconductor wafer using a xenon flash lamp (hereinafter simply referred to as "flash lamp" when meaning a xenon flash lamp), thereby raising the temperature of only the surface of the semiconductor wafer in an extremely short time (several milliseconds or less).

[0003] The emission spectral distribution of a xenon flash lamp is from the ultraviolet region to the near-infrared region, and its wavelength is shorter than that of a conventional halogen lamp, and almost coincides with the fundamental absorption band of a silicon semiconductor wafer. Therefore, when flash light is irradiated from a xenon flash lamp onto a semiconductor wafer, there is little transmitted light and the semiconductor wafer can be rapidly heated. It has also been found that if flash light is irradiated for an extremely short time of several milliseconds or less, only the vicinity of the surface of the semiconductor wafer can be selectively heated.

[0004] Such flash lamp annealing is used for processes that require heating in an extremely short time, for example, typically for activating impurities implanted in a semiconductor wafer. If flash light is irradiated from a flash lamp onto the surface of a semiconductor wafer into which impurities have been implanted by the ion implantation method, the temperature of the surface of the semiconductor wafer can be raised to the activation temperature in an extremely short time, and only impurity activation can be performed without deeply diffusing the impurities.

[0005] Typically, a heat treatment apparatus is used to perform such flash lamp annealing, which has a flash lamp above a chamber containing a semiconductor wafer and a halogen lamp below it (for example, Patent Document 1). In the apparatus disclosed in Patent Document 1, the semiconductor wafer is preheated by light irradiation from the halogen lamp, and then the surface of the semiconductor wafer is irradiated with flash light from the flash lamp. Preheating with the halogen lamp is performed because the surface of the semiconductor wafer does not easily reach the target temperature with flash light irradiation alone. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2011-159713 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] However, when preheating is performed using a halogen lamp, a certain amount of time is required from the time the halogen lamp is turned on until the target output is reached, and heat radiation continues for a while even after the halogen lamp is turned off. This has the problem that the diffusion length of impurities injected into the semiconductor wafer becomes relatively long.

[0008] Furthermore, halogen lamps primarily emit infrared light with relatively long wavelengths. In the spectral absorption rate of silicon semiconductor wafers, the absorption rate of infrared light with wavelengths of 1 μm or longer is low in the low-temperature range below 500°C. In other words, semiconductor wafers below 500°C do not absorb much infrared light irradiated from halogen lamps, resulting in inefficient heating in the initial stages of preheating.

[0009] One possible solution to these problems is to preheat semiconductor wafers using multiple LED lamps. LED lamps have faster power rise and fall times compared to halogen lamps. Also, LED lamps mainly emit visible light. Therefore, even with semiconductor wafers at relatively low temperatures below 500°C, the absorption rate of light irradiated from LED lamps is high, and by using LED lamps, efficient heating can be performed even in the initial stages of preheating.

[0010] However, because the output of each individual LED lamp is relatively weak, the intensity of light irradiated onto the semiconductor wafer is also relatively low. As a result, the heating efficiency of semiconductor wafers using LED lamps was not sufficient. Furthermore, in order to obtain a high irradiation intensity, a considerably large number of LED lamps had to be placed in a certain area.

[0011] The present invention has been made in view of the above problems, and aims to provide a heat treatment apparatus that can efficiently heat a substrate. [Means for solving the problem]

[0012] To solve the above problems, the invention of claim 1 provides a heat treatment apparatus for heating a substrate by irradiating the substrate with light, comprising: a chamber for housing the substrate; a holding part for holding the substrate within the chamber; an auxiliary light source provided on one side of the chamber for irradiating the substrate held by the holding part with light; and a flash lamp provided on the other side of the chamber for irradiating the substrate held by the holding part with flash light, wherein the auxiliary light source comprises a plurality of vertical cavity surface-emitting lasers. The apparatus further comprises a homogenizer between the chamber and the auxiliary light source, which homogenizes the light emitted from each of the plurality of vertical cavity surface-emitting lasers, and the homogenizer is in the shape of a plate formed by bundling together optical elements of rectangular prism members of quartz, with one-to-one correspondence to the plurality of vertical cavity surface-emitting lasers. It is characterized by the following:

[0013] Furthermore, the invention of claim 2 is characterized in that, in the heat treatment apparatus according to the invention of claim 1, the auxiliary light source includes a vertical cavity type surface-emitting laser that irradiates light of different wavelengths.

[0016] Furthermore, claims 3 The invention is A heat treatment apparatus for heating a substrate by irradiating the substrate with light comprises: a chamber for housing the substrate; a holding part for holding the substrate within the chamber; an auxiliary light source provided on one side of the chamber for irradiating the substrate held by the holding part with light; and a flash lamp provided on the other side of the chamber for irradiating the substrate held by the holding part with flash light, wherein the auxiliary light source comprises a plurality of vertical cavity surface-emitting lasers and Multiple LED lamps Equipped with, The aforementioned plurality of vertical cavity type surface-emitting lasers are, Arranged at a uniform density within a circular area Surrounding the aforementioned plurality of LED lamps Uniform density It is characterized by being arranged in a ring shape.

[0017] Furthermore, claims 4 The invention is claimed 3 The heat treatment apparatus according to the invention is characterized in that the auxiliary light source includes a vertical cavity surface-emitting laser that emits light of different wavelengths and an LED lamp that emits light of different wavelengths.

[0018] Furthermore, claims 5 The invention is claimed 3 In the heat treatment apparatus according to the invention, the auxiliary light source further comprises an additional vertical resonator type surface-emitting laser provided around the plurality of vertical resonator type surface-emitting lasers arranged in a ring, with the irradiation direction directed toward the substrate held by the holding part. [Effects of the Invention]

[0019] Claims 1 to Claims 5 According to this invention, the auxiliary light source is equipped with multiple vertical-cavity surface-emitting lasers, which allows for a high intensity of light irradiated onto the substrate and efficient heating of the substrate.

[0020] In particular, according to the invention of claim 2, since the auxiliary light source includes a vertical-cavity surface-emitting laser that emits light of different wavelengths, the entire surface of the substrate can be heated uniformly even if there are parts of the substrate that have a low absorption rate for light of a specific wavelength.

[0021] In particular, claims 1 According to this invention, since it further includes a homogenizer that homogenizes the light emitted from each of the multiple vertical-cavity surface-emitting lasers, the illuminance distribution on the irradiated surface of the substrate can be made uniform, and the in-plane temperature distribution of the substrate can also be made uniform.

[0022] In particular, according to the invention of claim 3 the auxiliary light source further includes a plurality of LED lamps, and the plurality of vertical cavity surface emitting lasers are arranged in an annular shape so as to surround the plurality of LED lamps. Therefore, highly directional light can be irradiated from the vertical cavity surface emitting lasers to the peripheral portion of the substrate where temperature drop is likely to occur, strongly heating the peripheral portion, and making the in-plane temperature distribution of the substrate uniform.

Brief Description of the Drawings

[0023] [Figure 1] It is a longitudinal sectional view showing the configuration of the heat treatment apparatus of the first embodiment. [Figure 2] It is a perspective view showing the overall appearance of the holding part. [Figure 3] It is a plan view of the susceptor. [Figure 4] It is a sectional view of the susceptor. [Figure 5] It is a plan view of the transfer mechanism. [Figure 6] It is a side view of the transfer mechanism. [Figure 7] It is a plan view showing the arrangement of a plurality of VCSELs. [Figure 8] It is a longitudinal sectional view showing the configuration of the heat treatment apparatus of the second embodiment. [Figure 9] It is a diagram schematically explaining the uniformization of the light distribution by the homogenizer. [Figure 10] It is a diagram showing the intensity distribution of the light emitted from the VCSEL. ​​​​​​​​​​​​​​ [Figure 16] This is a plan view showing the arrangement of multiple VCSELs and multiple LED lamps in the auxiliary heating section of the fourth embodiment. [Figure 17] This figure schematically shows the configuration of the heat treatment apparatus according to the fifth embodiment. [Figure 18] This figure shows the temperature change of a semiconductor wafer undergoing heat treatment using the heat treatment apparatus shown in Figure 17. [Modes for carrying out the invention]

[0024] Embodiments of the present invention will be described in detail below with reference to the drawings. In the following, expressions indicating relative or absolute positional relationships (e.g., "in one direction," "along one direction," "parallel," "orthogonal," "center," "concentric," "coaxial," etc.) shall, unless otherwise specified, not only strictly represent the positional relationship but also represent a state in which the object is displaced relative to the other object in terms of angle or distance within a tolerance or a range in which a similar level of function can be obtained. Similarly, expressions indicating equality (e.g., "identical," "equal," "homogeneous," etc.) shall, unless otherwise specified, not only represent a state in which the object is quantitatively strictly equal but also represent a state in which there is a difference in which a tolerance or a similar level of function can be obtained. Furthermore, expressions indicating shape (e.g., "circular," "square," "cylindrical," etc.) shall, unless otherwise specified, not only strictly represent the geometric shape but also represent a shape within a range in which a similar level of effect can be obtained, and may include, for example, irregularities or chamfers. Additionally, expressions such as "equipped," "possessing," "containing," and "having" a component are not exclusive expressions that exclude the existence of other components. Furthermore, the expression "at least one of A, B, and C" includes "A only," "B only," "C only," "any two of A, B, and C," and "all of A, B, and C."

[0025] <First Embodiment> Figure 1 is a longitudinal cross-sectional view showing the configuration of the heat treatment apparatus 1 according to the present invention. The heat treatment apparatus 1 in Figure 1 is a flash lamp annealing apparatus that heats a disc-shaped semiconductor wafer W, which is used as a substrate, by flashing light onto the wafer. The size of the semiconductor wafer W to be processed is not particularly limited, but for example, it may be φ300 mm or φ450 mm. Note that in Figure 1 and subsequent figures, the dimensions and number of parts are exaggerated or simplified as necessary for ease of understanding.

[0026] The heat treatment apparatus 1 comprises a chamber 6 for housing a semiconductor wafer W, a flash heating unit 5 incorporating multiple flash lamps FL, and an auxiliary heating unit 4 equipped with multiple VCSELs (Vertical Cavity Surface Emitting Lasers) 45. The flash heating unit 5 is located on the upper side of the chamber 6, while the auxiliary heating unit 4 is located on the lower side. The heat treatment apparatus 1 also includes a holding unit 7 inside the chamber 6 for holding the semiconductor wafer W in a horizontal position, and a transfer mechanism 10 for transferring the semiconductor wafer W between the holding unit 7 and the outside of the apparatus. Furthermore, the heat treatment apparatus 1 includes a control unit 3 that controls the operating mechanisms provided in the auxiliary heating unit 4, the flash heating unit 5, and the chamber 6 to perform heat treatment on the semiconductor wafer W.

[0027] Chamber 6 is constructed by mounting quartz chamber windows on the top and bottom of a cylindrical chamber side section 61. The chamber side section 61 has a roughly cylindrical shape with openings at the top and bottom. The upper opening is closed by an upper chamber window 63, and the lower opening is closed by a lower chamber window 64. The upper chamber window 63, which forms the ceiling of chamber 6, is a disc-shaped member made of quartz and functions as a quartz window that transmits flash light emitted from the flash heating section 5 into chamber 6. Similarly, the lower chamber window 64, which forms the floor of chamber 6, is also a disc-shaped member made of quartz and functions as a quartz window that transmits light from the auxiliary heating section 4 into chamber 6.

[0028] Furthermore, a reflective ring 68 is attached to the upper part of the inner wall surface of the chamber side portion 61, and a reflective ring 69 is attached to the lower part. Both reflective rings 68 and 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 portion 61. On the other hand, the lower reflective ring 69 is attached by fitting it from the lower side of the chamber side portion 61 and securing it with screws (not shown). In other words, both reflective rings 68 and 69 are detachably attached to the chamber side portion 61. The inner space of the chamber 6, that is, the space enclosed by the upper chamber window 63, the lower chamber window 64, the chamber side portion 61, and the reflective rings 68 and 69, is defined as the heat treatment space 65.

[0029] By attaching the reflective 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 formed by the central portion of the inner wall surface of the chamber side portion 61 where the reflective rings 68 and 69 are not attached, the lower end surface of the reflective ring 68, and the upper end surface of the reflective 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 holding portion 7 that holds the semiconductor wafer W. The chamber side portion 61 and the reflective rings 68 and 69 are made of a metal material (for example, stainless steel) with excellent strength and heat resistance.

[0030] Furthermore, a transport opening (furnace opening) 66 is provided on the side portion 61 of the chamber for loading and unloading semiconductor wafers W into and out of the chamber 6. The transport opening 66 can be opened and closed by a gate valve 185. The transport opening 66 is connected in communication with the outer surface of the recess 62. Therefore, when the gate valve 185 is open, semiconductor wafers W can be loaded into the heat treatment space 65 from the transport opening 66 through the recess 62 and unloaded from the heat treatment space 65. When the gate valve 185 closes the transport opening 66, the heat treatment space 65 inside the chamber 6 becomes a sealed space.

[0031] Furthermore, a through-hole 61a is drilled in the side portion 61 of the chamber. A radiation thermometer 20 is attached to the portion of the outer wall surface of the side portion 61 of the chamber where the through-hole 61a is provided. The through-hole 61a is a cylindrical hole for guiding infrared light emitted from the lower surface of the semiconductor wafer W held by the susceptor 74 (described later) to the radiation thermometer 20. The through-hole 61a is provided at an inclination with respect to the horizontal direction such that its axis in the direction of penetration intersects with the main surface of the semiconductor wafer W held by the susceptor 74. Therefore, the radiation thermometer 20 is provided diagonally below the susceptor 74. A transparent window 21 made of barium fluoride material that transmits infrared light in the wavelength range measurable by the radiation thermometer 20 is attached to the end of the through-hole 61a facing the heat treatment space 65.

[0032] Furthermore, a gas supply hole 81 for supplying a processing gas to the heat treatment space 65 is formed in the upper part of the inner wall of the chamber 6. The gas supply hole 81 is formed in a position above the recess 62 and may be provided in the reflecting ring 68. The gas supply hole 81 is connected to a gas supply pipe 83 via a buffer space 82 formed in an annular shape inside the side wall of the chamber 6. The gas supply pipe 83 is connected to a processing gas supply source 85. A valve 84 is also interposed in the path of the gas supply pipe 83. When the valve 84 is opened, processing gas is supplied from the processing gas supply source 85 to the buffer space 82. The processing gas that flows into the buffer space 82 spreads out within the buffer space 82, which has less fluid resistance than the gas supply hole 81, and is supplied from the gas supply hole 81 into the heat treatment space 65. As the processing gas, for example, an inert gas such as nitrogen (N2), or a reactive gas such as hydrogen (H2), ammonia (NH3), or a mixed gas of these can be used (in this embodiment, nitrogen gas).

[0033] On the other hand, a gas exhaust port 86 for exhausting gas from the heat treatment space 65 is formed in the lower part of the inner wall of the chamber 6. The gas exhaust port 86 is formed in a position below the recess 62 and may be provided in the reflecting ring 69. The gas exhaust port 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 the exhaust section 190. A valve 89 is interposed in the path of the gas exhaust pipe 88. When the valve 89 is opened, the gas from the heat treatment space 65 is discharged from the gas exhaust port 86 through the buffer space 87 to the gas exhaust pipe 88. Note that there may be multiple gas supply holes 81 and gas exhaust holes 86 along the circumferential direction of the chamber 6, or they may be slit-shaped. Also, the processing gas supply source 85 and the exhaust section 190 may be mechanisms provided in the heat treatment apparatus 1, or they may be utilities of the factory where the heat treatment apparatus 1 is installed.

[0034] Figure 2 is a perspective view showing the overall appearance of the holding part 7. The holding part 7 is composed of a base ring 71, a connecting part 72, and a susceptor 74. The base ring 71, the connecting part 72, and the susceptor 74 are all made of quartz. In other words, the entire holding part 7 is made of quartz.

[0035] The base ring 71 is a quartz material with an arc shape, partially missing from its annular shape. This 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 by the wall surface of the chamber 6 by being placed on the bottom surface of the recess 62 (see Figure 1). Multiple connecting parts 72 (four in this embodiment) are erected on the upper surface of the base ring 71 along the circumferential direction of its annular shape. The connecting parts 72 are also made of quartz material and are fixed to the base ring 71 by welding.

[0036] The susceptor 74 is supported by four connecting parts 72 provided on the base ring 71. Figure 3 is a plan view of the susceptor 74. Figure 4 is a cross-sectional view of the susceptor 74. The susceptor 74 comprises a retaining plate 75, a guide ring 76, and a plurality of substrate support pins 77. The retaining plate 75 is a substantially circular, flat member made of quartz. The diameter of the retaining plate 75 is larger than the diameter of the semiconductor wafer W. That is, the retaining plate 75 has a planar size larger than the semiconductor wafer W.

[0037] A guide ring 76 is installed on the upper peripheral edge of the retaining 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 circumference of the guide ring 76 is tapered so as to widen upward from the retaining plate 75. The guide ring 76 is made of quartz, the same material as the retaining plate 75. The guide ring 76 may be welded to the upper surface of the retaining plate 75, or it may be fixed to the retaining plate 75 by a separately processed pin or the like. Alternatively, the retaining plate 75 and the guide ring 76 may be manufactured as a single integrated member.

[0038] The area of ​​the upper surface of the retaining plate 75 that is inside the guide ring 76 is a planar retaining surface 75a for holding the semiconductor wafer W. Multiple substrate support pins 77 are erected on the retaining surface 75a of the retaining plate 75. In this embodiment, a total of 12 substrate support pins 77 are erected at 30° intervals along the circumference of the outer circumference of the retaining surface 75a (the inner circumference of the guide ring 76) concentric with the outer circumference of the retaining surface 75a. The diameter of the circle in 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, and if the diameter of the semiconductor wafer W is φ300 mm, the diameter is φ270 mm to φ280 mm (φ270 mm in this embodiment). Each substrate support pin 77 is made of quartz. Multiple substrate support pins 77 may be provided on the upper surface of the retaining plate 75 by welding, or they may be processed integrally with the retaining plate 75.

[0039] Returning to Figure 2, the four connecting parts 72 erected on the base ring 71 and the peripheral edge of the holding plate 75 of the susceptor 74 are fixed by welding. In other words, the susceptor 74 and the base ring 71 are fixedly connected by the connecting parts 72. The holding part 7 is mounted in the chamber 6 by the base ring 71 of the holding part 7 being supported by the wall surface of the chamber 6. When the holding part 7 is mounted in the chamber 6, the holding plate 75 of the susceptor 74 is in a horizontal position (a position in which the normal coincides with the vertical direction). In other words, the holding surface 75a of the holding plate 75 is a horizontal plane.

[0040] The semiconductor wafer W, once loaded into the chamber 6, is placed and held in a horizontal position on the susceptor 74 of the holding unit 7 mounted on the chamber 6. At this time, the semiconductor wafer W is supported by 12 substrate support pins 77 erected on the holding plate 75 and held by the susceptor 74. More precisely, the upper ends of the 12 substrate support pins 77 contact the lower surface of the semiconductor wafer W to support it. Since the height of the 12 substrate support pins 77 (the distance from the upper end of the substrate support pins 77 to the holding surface 75a of the holding plate 75) is uniform, the semiconductor wafer W can be supported in a horizontal position by the 12 substrate support pins 77.

[0041] Furthermore, the semiconductor wafer W is supported by a plurality of substrate support pins 77 at a predetermined distance from the holding surface 75a of the holding plate 75. The thickness of the guide ring 76 is greater than the height of the substrate support pins 77. Therefore, horizontal displacement of the semiconductor wafer W supported by the plurality of substrate support pins 77 is prevented by the guide ring 76.

[0042] Furthermore, as shown in Figures 2 and 3, the holding plate 75 of the susceptor 74 has an opening 78 that penetrates vertically. The opening 78 is provided for the radiation thermometer 20 to receive synchrotron radiation (infrared light) emitted from the lower surface of the semiconductor wafer W. That is, the radiation thermometer 20 measures the temperature of the semiconductor wafer W by receiving light emitted from the lower surface of the semiconductor wafer W through the opening 78 and a transparent window 21 fitted in the through hole 61a of the chamber side portion 61. In addition, the holding plate 75 of the susceptor 74 has four through holes 79 through which the lift pins 12 of the transfer mechanism 10, which will be described later, pass the semiconductor wafer W.

[0043] Figure 5 is a plan view of the transfer mechanism 10. Figure 6 is a side view of the transfer mechanism 10. The transfer mechanism 10 comprises two transfer arms 11. The transfer arms 11 are shaped like arcs that generally follow the annular recess 62. Two lift pins 12 are erected on each transfer arm 11. The transfer arms 11 and lift pins 12 are made of quartz. Each transfer arm 11 is rotatable by a horizontal movement mechanism 13. The horizontal movement mechanism 13 moves the pair of transfer arms 11 horizontally between a transfer operation position (solid line position in Figure 5) where the semiconductor wafer W is transferred to the holding part 7 and a retracted position (dotted line position in Figure 5) where the semiconductor wafer W held by the holding part 7 does not overlap in a plan view. The horizontal movement mechanism 13 may consist of individual motors that rotate each transfer arm 11, or it may consist of a linkage mechanism that uses a single motor to rotate a pair of transfer arms 11 in conjunction with each other.

[0044] Furthermore, the pair of transfer arms 11 are moved up and down 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 Figures 2 and 3) drilled 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 and removes the lift pins 12 from the through holes 79, and the horizontal movement mechanism 13 moves the pair of transfer arms 11 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 holding part 7. Since 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. Furthermore, an exhaust mechanism (not shown) is also provided near the area where the drive unit (horizontal movement mechanism 13 and lifting mechanism 14) of the transfer mechanism 10 is located, so that the atmosphere around the drive unit of the transfer mechanism 10 is discharged to the outside of the chamber 6.

[0045] Returning to Figure 1, the flash heating unit 5, located above the chamber 6, is configured with a light source consisting of multiple (30 in this embodiment) xenon flash lamps FL inside a housing 51, and a reflector 52 provided to cover the top of the light source. A lamp light emission window 53 is also attached to the bottom of the housing 51 of the flash heating unit 5. The lamp light emission window 53, which constitutes the floor of the flash heating unit 5, is a plate-shaped quartz window made of quartz. As the flash heating unit 5 is installed above the chamber 6, the lamp light emission window 53 faces the upper chamber window 63. The flash lamps FL irradiate the 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.

[0046] Each of the multiple flash lamps FL is a rod-shaped lamp with a long cylindrical shape, and they are arranged in a planar manner such that their longitudinal directions are parallel to each other along the main surface (i.e., along the horizontal direction) of the semiconductor wafer W held by the holding part 7. Therefore, the plane formed by the arrangement of the flash lamps FL is also a horizontal plane. The area in which the multiple flash lamps FL are arranged is larger than the planar size of the semiconductor wafer W.

[0047] A xenon flash lamp FL comprises a cylindrical glass tube (discharge tube) containing xenon gas, with an anode and cathode connected to capacitors at both ends, and a trigger electrode attached to the outer surface of the glass tube. Since xenon gas is an electrically insulating material, electricity does not flow through the glass tube under normal conditions, even if charge is stored in the capacitor. However, when a high voltage is applied to the trigger electrode to break the insulation, the electricity stored in the capacitor flows instantaneously through the glass tube, and light is emitted due to the excitation of xenon atoms or molecules at that time. In such a xenon flash lamp FL, the electrostatic energy previously stored in the capacitor is converted into extremely short light pulses of 0.1 milliseconds to 100 milliseconds, giving it the characteristic of being able to emit extremely strong light compared to a continuously lit light source such as a halogen lamp. In other words, a flash lamp FL is a pulse-emitting lamp that emits light instantaneously in an extremely short time of less than one second. Furthermore, the illumination time of the flash lamp FL can be adjusted by the coil constant of the lamp power supply that provides power to the flash lamp FL.

[0048] Furthermore, the reflector 52 is positioned above the multiple flash lamps FL so as to cover them all. The basic function of the reflector 52 is to reflect the flash light emitted from the multiple flash lamps FL towards the heat treatment space 65. The reflector 52 is made of an aluminum alloy plate, and its surface (the side facing the flash lamps FL) is roughened by blasting.

[0049] The auxiliary heating unit 4, located below the chamber 6, has multiple VCSELs 45 built into the inside of the housing 41. The auxiliary heating unit 4 is an auxiliary light source that heats the semiconductor wafer W by irradiating light into the heat treatment space 65 from below the chamber 6 through the lower chamber window 64 using multiple VCSELs 45.

[0050] Figure 7 is a plan view showing the arrangement of multiple VCSELs 45. The auxiliary heating section 4 has multiple Number The VCSEL45s are arranged, but in Figure 7, the number is simplified for illustrative purposes. Unlike conventional halogen lamps, which are rod-shaped lamps, each VCSEL45 is a point light source. Multiple VCSEL45s are arranged along the main surface of the semiconductor wafer W held by the holding part 7 (i.e., along the horizontal direction). Therefore, the plane formed by the arrangement of multiple VCSEL45s is a horizontal plane.

[0051] Furthermore, as shown in Figure 7, the multiple VCSELs 45 are arranged concentrically. More specifically, the multiple VCSELs 45 are arranged concentrically with the central axis CX of the semiconductor wafer W held in the holding part 7. In each concentric circle, the multiple VCSELs 45 are arranged at equal intervals. For example, in the example shown in Figure 7, in the second concentric circle from the inside, eight VCSELs 45 are arranged evenly at 45° intervals.

[0052] A VCSEL (Vertical Cavity Surface Emitting Laser) 45 is a type of semiconductor laser that emits light perpendicular to the surface of a semiconductor substrate. Compared to LEDs, VCSELs 45 can emit light of higher intensity and also emit highly directional light. Multiple VCSELs 45 in the first embodiment emit light with a wavelength of 940 nm. The VCSELs 45 also function as continuous-on lamps that emit light continuously for at least one second.

[0053] Each of the multiple VCSELs 45 receives power from the power supply unit 49 (Figure 1). forceWhen power is supplied, the VCSEL 45 emits light. The power supply unit 49 individually adjusts the power supplied to each of the multiple VCSELs 45 according to the control of the control unit 3. In other words, the power supply unit 49 can individually adjust the light emission intensity and light emission time of each of the multiple VCSELs 45 arranged in the auxiliary heating unit 4.

[0054] 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 general computer. Specifically, the control unit 3 includes a CPU, which is a circuit that performs various calculations; 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 for storing control software and data. Processing in the heat treatment apparatus 1 proceeds when the CPU of the control unit 3 executes a predetermined processing program.

[0055] In addition to the above configuration, the heat treatment apparatus 1 is equipped with various cooling structures to prevent excessive temperature rise in the auxiliary heating section 4, flash heating section 5, and chamber 6 due to thermal energy generated from the VCSEL 45 and flash lamp FL during the heat treatment of the semiconductor wafer W. For example, water cooling pipes (not shown) are provided in the wall of the chamber 6. Furthermore, the auxiliary heating section 4 and flash heating section 5 are air-cooled structures that dissipate heat by forming a gas flow inside. In addition, air is supplied to the gap between the upper chamber window 63 and the lamp light emission window 53 to cool the flash heating section 5 and the upper chamber window 63.

[0056] Next, the processing operation in the heat treatment apparatus 1 will be described. Here, a typical heat treatment operation for a standard semiconductor wafer (product wafer) W that will become a product will be described. The semiconductor wafer W to be processed is a silicon (Si) semiconductor substrate into which impurities have been implanted by ion implantation as a front-end process. The activation of these impurities is performed by the annealing process carried out by the heat treatment apparatus 1. The processing procedure for the semiconductor wafer W described below proceeds as the control unit 3 controls each operating mechanism of the heat treatment apparatus 1.

[0057] First, prior to processing the semiconductor wafer W, the supply valve 84 is opened and the exhaust valve 89 is opened, initiating the supply and exhaust of air into the chamber 6. When valve 84 is opened, nitrogen gas is supplied to the heat treatment space 65 from the gas supply hole 81. When valve 89 is opened, the gas inside the chamber 6 is exhausted from the gas exhaust hole 86. As a result, the nitrogen gas supplied from the top of the heat treatment space 65 inside the chamber 6 flows downward and is exhausted from the bottom of the heat treatment space 65.

[0058] Next, the gate valve 185 opens, the transport opening 66 is opened, and the semiconductor wafer W to be processed is transported through the transport opening 66 by a transport robot outside the apparatus into the heat treatment space 65 inside the chamber 6. At this time, there is a risk that the atmosphere outside the apparatus may be drawn in as the semiconductor wafer W is transported in, but since nitrogen gas is continuously supplied to the chamber 6, the nitrogen gas flows out from the transport opening 66, minimizing the entrainment of such external atmosphere.

[0059] The semiconductor wafer W, loaded by the transport robot, moves forward to a position directly above the holding section 7 and stops. 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 pin 12 to protrude from the upper surface of the holding plate 75 of the susceptor 74 through the through hole 79 and receive the semiconductor wafer W. At this time, the lift pin 12 rises above the upper end of the substrate support pin 77.

[0060] After the semiconductor wafer W is placed on the lift pin 12, the transport robot exits the heat treatment space 65, and the transport opening 66 is closed by the gate valve 185. Then, as the pair of transfer arms 11 descend, the semiconductor wafer W is transferred from the transfer mechanism 10 to the susceptor 74 of the holding section 7 and held from below in a horizontal position. The semiconductor wafer W is supported by a plurality of substrate support pins 77 erected on the holding plate 75 and held by the susceptor 74. The semiconductor wafer W is also held in the holding section 7 with the patterned surface and impurities injected facing upwards. A predetermined gap is formed between the back surface (the main surface opposite to the front surface) of the semiconductor wafer W, which is 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.

[0061] After the semiconductor wafer W is held horizontally from below by the susceptor 74 of the holding part 7 made of silica, light is irradiated from multiple VCSELs 45 of the auxiliary heating part 4 to start preheating (assisted heating). The light emitted from the multiple VCSELs 45 passes through the lower chamber window 64 and the susceptor 74, which are made of silica, and irradiates the lower surface of the semiconductor wafer W. The semiconductor wafer W is preheated by the light irradiation from the VCSELs 45 and its temperature rises. The transfer arm 11 of the transfer mechanism 10 is retracted inside the recess 62, so it does not interfere with heating by the VCSELs 45.

[0062] The temperature of the semiconductor wafer W, which is heated by light irradiation from the VCSEL 45, is measured by the radiation thermometer 20. The measured temperature of the semiconductor wafer W is transmitted to the control unit 3. The control unit 3 monitors whether the temperature of the semiconductor wafer W, which is heated by light irradiation from the VCSEL 45, has reached a predetermined preheating temperature T1, and controls the power supply unit 49 to adjust the output of the VCSEL 45. That is, the control unit 3 feedback controls the output of the VCSEL 45 based on the measurement value from 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 350°C to 600°C (600°C in this embodiment), so that there is no risk of impurities added to the semiconductor wafer W diffusing due to heat.

[0063] After the semiconductor wafer W reaches the preheating temperature T1, the control unit 3 temporarily maintains the semiconductor wafer W at that preheating temperature T1. Specifically, when the temperature of the semiconductor wafer W, as measured by the radiation thermometer 20, reaches the preheating temperature T1, the control unit 3 adjusts the output of the VCSEL 45 to maintain the temperature of the semiconductor wafer W at approximately the preheating temperature T1.

[0064] When the semiconductor wafer W reaches the preheating temperature T1 and a predetermined time has elapsed, the flash lamp FL of the flash heating unit 5 irradiates the surface of the semiconductor wafer W held by the susceptor 74 with flash light. At this time, a portion of the flash light emitted from the flash lamp FL goes directly into the chamber 6, and another portion is reflected by the reflector 52 before going into the chamber 6, and the semiconductor wafer W is flash-heated by the irradiation of these flash lights.

[0065] Flash heating is performed by irradiation with flash light (blink) from a flash lamp FL, allowing the surface temperature of the semiconductor wafer W to be raised in a short time. Specifically, the flash light irradiated from the flash lamp FL is an extremely short and strong flash with an irradiation time of approximately 0.1 milliseconds to 100 milliseconds, where electrostatic energy previously stored in a capacitor is converted into an extremely short light pulse. The surface temperature of the semiconductor wafer W, flash-heated by irradiation with flash light from the flash lamp FL, instantaneously rises to a processing temperature T2 of 1000°C or more, and after the impurities injected into the semiconductor wafer W are activated, the surface temperature rapidly decreases. 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, so that the impurities injected into the semiconductor wafer W can be activated while suppressing thermal diffusion of the impurities. Furthermore, since 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 about 0.1 to 100 milliseconds, during which no diffusion occurs.

[0066] After the flash heating process is completed, the light irradiation from the VCSEL 45 is also stopped after a predetermined time has elapsed. This causes the semiconductor wafer W to rapidly cool down from the preheating temperature T1. The temperature of the semiconductor wafer W during the cooling process is measured by the radiation thermometer 20, and the measurement result is transmitted to the control unit 3. The control unit 3 monitors whether the temperature of the semiconductor wafer W has cooled down to a predetermined temperature based on the measurement result from the radiation thermometer 20. After the temperature of the semiconductor wafer W has cooled down to below the predetermined temperature, the pair of transfer arms 11 of the transfer mechanism 10 move horizontally again from the retracted position to the transfer operation position and rise, causing the lift pin 12 to protrude from the upper surface of the susceptor 74 and receive the heat-treated semiconductor wafer W from the susceptor 74. Subsequently, the transport opening 66, which had been closed by the gate valve 185, is opened, and the semiconductor wafer W placed on the lift pin 12 is transported out of the chamber 6 by a transport robot outside the device, completing the heating process of the semiconductor wafer W.

[0067] In the first embodiment, the semiconductor wafer W is preheated to a preheating temperature T1 by light irradiation from the VCSEL 45, and then the surface of the semiconductor wafer W is irradiated with flash light from the flash lamp FL to raise the temperature of the surface to a processing temperature T2. The VCSEL 45 is capable of emitting light of relatively high intensity compared to LEDs. Therefore, by irradiating with light from multiple VCSEL 45s, the intensity of the light irradiated onto the semiconductor wafer W during preheating can be increased, and the semiconductor wafer W can be heated efficiently. In addition, because the VCSEL 45 emits relatively high-intensity light, it is possible to reduce the number of VCSEL 45s installed in the auxiliary heating unit 4 compared to when the auxiliary heating unit 4 is configured with LED lamps.

[0068] In the first embodiment, the wavelength of light irradiated from the multiple VCSELs 45 was set to a single wavelength of 940 nm. However, instead, multiple wavelengths of light may be irradiated from the multiple VCSELs 45. That is, the auxiliary heating unit 4 may be provided with multiple types of VCSELs 45 with different wavelengths of emitted light. When light of a single wavelength is irradiated from multiple VCSELs 45, if a film with low absorption for that wavelength of light is formed on a part of the semiconductor wafer W, the temperature of that part may become relatively low, potentially impairing the in-plane uniformity of the temperature distribution. By irradiating light of multiple wavelengths from multiple VCSELs 45, even if a film with low absorption for a specific wavelength of light is formed on a part of the semiconductor wafer W, the entire surface of the semiconductor wafer W can be heated uniformly, improving the in-plane uniformity of the temperature distribution.

[0069] <Second Embodiment> Next, a second embodiment of the present invention will be described. Figure 8 is a longitudinal cross-sectional view showing the configuration of the heat treatment apparatus 1a of the second embodiment. In Figure 8, the same reference numerals are used for elements that are the same as those in the first embodiment (Figure 1). The difference between the heat treatment apparatus 1a of the second embodiment and the heat treatment apparatus 1 of the first embodiment is that it is provided with a homogenizer 48 that equalizes the distribution of light emitted from each of the multiple VCSELs 45.

[0070] The homogenizer 48 is a quartz plate-like member provided between the multiple VCSELs 45 and the lower chamber window 64 of the chamber 6. However, although the homogenizer 48 is a plate-like member, it is not a single plate, but rather has a plate-like shape as a result of bundling together multiple diffractive optical elements 48a.

[0071] Figure 9 schematically illustrates the homogenization of the light distribution by the homogenizer 48. A plate-shaped homogenizer 48 is formed by bundling together multiple diffractive optical elements 48a arranged in a planar manner. Each diffractive optical element 48a is a quartz rectangular prism member (quartz rod) with six polished faces. The multiple diffractive optical elements 48a constituting the homogenizer 48 are provided in a one-to-one correspondence with multiple VCSELs 45. Therefore, the light emitted from each VCSEL 45 will be incident on one of the diffractive optical elements 48a.

[0072] Figure 10 shows the intensity distribution of light emitted from the VCSEL45. As previously mentioned, the VCSEL45 emits relatively directional light, so the intensity is highest near the center of the optical axis and decreases as it moves away from the optical axis. Therefore, the intensity distribution of light emitted from the VCSEL45 is close to a Gaussian distribution as shown in Figure 10. As a result, when light is directly irradiated onto a semiconductor wafer W from multiple VCSEL45s, areas of high and low illumination may appear on the irradiated surface of the semiconductor wafer W, potentially causing spotty illumination unevenness. Consequently, the in-plane temperature distribution of the semiconductor wafer W during preheating will also be non-uniform.

[0073] As shown in Figure 9, when light emitted from each VCSEL 45 is incident from the lower surface of the corresponding diffractive optical element 48a, the light undergoes repeated total internal reflection within the diffractive optical element 48a, and the light overlaps and becomes uniform on the upper surface of the diffractive optical element 48a. Figure 11 shows the intensity distribution of the light that has passed through the homogenizer 48. Although the light emitted from the VCSEL 45 was highly directional, the light is homogenized by the diffractive optical element 48a, resulting in a uniform intensity distribution of the light that has passed through the homogenizer 48, as shown in Figure 11.

[0074] Light emitted from multiple VCSELs 45 and passing through the homogenizer 48 is irradiated onto the semiconductor wafer W, eliminating uneven illumination on the irradiated surface of the semiconductor wafer W and resulting in a uniform illumination distribution. As a result, the in-plane temperature distribution of the semiconductor wafer W during preheating also becomes uniform.

[0075] The configuration of the heat treatment apparatus 1a in the second embodiment is the same as that of the heat treatment apparatus 1 in the first embodiment, except that it is equipped with a homogenizer 48. Furthermore, the processing procedure for the semiconductor wafer W in the heat treatment apparatus 1a of the second embodiment is also the same as that of the first embodiment.

[0076] In the second embodiment, a homogenizer 48 is provided between the chamber 6 and the plurality of VCSELs 45 to homogenize the light emitted from each of the plurality of VCSELs 45. As a result, a uniform illuminance distribution can be obtained on the upper surface of the homogenizer 48, and the illuminance distribution on the irradiated surface of the semiconductor wafer W becomes uniform, and the in-plane temperature distribution of the semiconductor wafer W can also be made uniform.

[0077] <Third Embodiment> Next, a third embodiment of the present invention will be described. Figure 12 is a longitudinal cross-sectional view showing the configuration of the heat treatment apparatus 1b of the third embodiment. In Figure 12, the same reference numerals are used for elements that are the same as those in the first embodiment (Figure 1). The difference between the heat treatment apparatus 1b of the third embodiment and the heat treatment apparatus 1 of the first embodiment is that the auxiliary heating section 4 is provided with a VCSEL 45 and an LED (Light Emitting Diode) lamp 47.

[0078] The auxiliary heating unit 4 of the third embodiment comprises a plurality of VCSELs 45 and a plurality of LED lamps 47. The LED lamps 47 include light-emitting diodes. Light-emitting diodes are a type of diode that emits light through the electroluminescence effect when a voltage is applied in the forward direction.

[0079] Figure 13 is a plan view showing the arrangement of multiple VCSELs 45 and multiple LED lamps 47 in the auxiliary heating unit 4. The multiple LED lamps 47 are arranged at a uniform density in a circular area. Multiple VCSELs 45 are arranged at a uniform density in an annular area surrounding the circular area where the multiple LED lamps 47 are arranged. In other words, in the auxiliary heating unit 4 of the third embodiment, multiple LED lamps 47 are arranged in the center, and multiple VCSELs 45 are arranged around the periphery.

[0080] Figure 14 schematically illustrates the heating of a semiconductor wafer W by a mixed light source consisting of an LED lamp 47 and a VCSEL 45. The VCSEL 45 emits highly directional light that hardly spreads, while the LED lamp 47 emits... Light It shows a relatively spreading tendency. When the semiconductor wafer W is preheated using only multiple LED lamps 47, the temperature of the peripheral part of the semiconductor wafer W tends to be relatively lower than that of the central part.

[0081] In the third embodiment, multiple LED lamps 47 are arranged in the center of the auxiliary heating unit 4, and multiple VCSELs 45 are arranged around the periphery. That is, multiple VCSELs 45 are arranged to face the periphery of the semiconductor wafer W, which tends to get cold during preheating, and multiple LED lamps 47 are arranged to face the center of the semiconductor wafer W. This allows highly directional light to be irradiated from the VCSELs 45 onto the periphery of the semiconductor wafer W, which tends to get cold during preheating, thereby relatively increasing the illuminance of the periphery. As a result, the periphery of the semiconductor wafer W, which tends to get cold, is strongly heated, eliminating the temperature drop at the periphery and making the in-plane temperature distribution of the semiconductor wafer W uniform during preheating.

[0082] The configuration of the heat treatment apparatus 1b of the third embodiment is the same as that of the heat treatment apparatus 1 of the first embodiment, except that the auxiliary heating section 4 is equipped with a VCSEL 45 and an LED lamp 47. Furthermore, the processing procedure for the semiconductor wafer W in the heat treatment apparatus 1b of the third embodiment is the same as that of the first embodiment.

[0083] In the third embodiment, an auxiliary heating unit 4, which is an auxiliary light source, is provided with an LED lamp 47 in addition to the VCSEL 45, and a plurality of VCSELs 45 are arranged in a ring shape surrounding the plurality of LED lamps 47. This allows highly directional light to be irradiated from the VCSEL 45 onto the peripheral area of ​​the semiconductor wafer W, where temperature drops tend to occur during preheating, thereby strongly heating the peripheral area and making the in-plane temperature distribution of the semiconductor wafer W uniform during preheating.

[0084] Generally, the unit price of a VCSEL 45 is higher than that of an LED lamp 47. However, by providing VCSELs 45 only to the peripheral areas of the semiconductor wafer W where temperature drops are likely to occur, and using inexpensive LED lamps 47 for the other parts, it is possible to achieve uniformity of the in-plane temperature distribution of the semiconductor wafer W while suppressing cost increases.

[0085] At least one of the multiple VCSELs 45 and the multiple LED lamps 47 may be configured to emit light of multiple different wavelengths. That is, the auxiliary heating unit 4 may be provided with multiple types of VCSELs 45 and / or multiple types of LED lamps 47 with different wavelengths of emitted light. Similar to the first embodiment, by irradiating the semiconductor wafer W with light of multiple wavelengths from multiple VCSELs 45 and / or multiple LED lamps 47, even if a film with low absorption for a specific wavelength of light is formed on a part of the semiconductor wafer W, the entire surface of the semiconductor wafer W can be heated uniformly, thereby improving the in-plane uniformity of the temperature distribution.

[0086] <Fourth Embodiment> Next, a fourth embodiment of the present invention will be described. Figure 15 is a side view showing the configuration of the auxiliary heating unit 4 of the fourth embodiment. Figure 16 is a plan view showing the arrangement of multiple VCSELs 45 and multiple LED lamps 47 in the auxiliary heating unit 4 of the fourth embodiment.

[0087] In the fourth embodiment, additional VCSELs 45 are arranged around the auxiliary heating unit 4 of the third embodiment. The additional VCSELs 45 are provided at an angle in a region outside the semiconductor wafer W held by the holding unit 7. More specifically, as in the third embodiment, the plurality of LED lamps 47 are arranged at a uniform density in a circular region. The plurality of VCSELs 45 are arranged at a uniform density in an annular region surrounding the circular region where the plurality of LED lamps 47 are arranged. Furthermore, an additional plurality of VCSELs 45 are arranged around the annular region where the plurality of VCSELs 45 are arranged. The additional plurality of VCSELs 45 provided in the region outside the semiconductor wafer W are arranged at an angle so that their irradiation direction faces the lower peripheral edge of the semiconductor wafer W. The configuration of the fourth embodiment is the same as in the third embodiment, except for the provision of the additional plurality of VCSELs 45. Beauty The processing procedure is the same as in the third embodiment.

[0088] In the fourth embodiment, similar to the third embodiment, the peripheral portion of the semiconductor wafer W, which is prone to temperature drop during preheating, can be strongly heated by irradiating it with highly directional light from the VCSEL 45, thereby making the in-plane temperature distribution of the semiconductor wafer W uniform during preheating. Furthermore, in the fourth embodiment, the semiconductor wafer W can be heated more efficiently by irradiating the semiconductor wafer W with additional light from an additional VCSEL 45.

[0089] <Fifth Embodiment> Next, a fifth embodiment of the present invention will be described. Figure 17 is a schematic diagram showing the configuration of the heat treatment apparatus 100 of the fifth embodiment. The heat treatment apparatus 100 of the fifth embodiment does not have a flash lamp and is a rapid thermal processing apparatus (RTP apparatus) equipped with a plurality of VCSELs 45.

[0090] The heat treatment apparatus 100 includes an upper heating section 150 above the chamber 110 that houses the semiconductor wafer W, and a lower heating section 140 below the chamber 110. A quartz susceptor 170 is provided inside the chamber 110. Inside the chamber 110, the semiconductor wafer W to be processed is supported by the susceptor 170. Also, similar to the first embodiment, light-transmitting quartz windows (not shown) are provided above and below the chamber 110.

[0091] The lower heating section 140 is equipped with multiple VCSELs 45, similar to the auxiliary heating section 4 in the first embodiment. Similarly, the upper heating section 150 is also equipped with multiple VCSELs 45. The heat treatment apparatus 100 heats the semiconductor wafer W by irradiating the chamber 110 with light from above and below using the multiple VCSELs 45.

[0092] Figure 18 shows the temperature change of a semiconductor wafer W undergoing heat treatment by the heat treatment apparatus 100. The semiconductor wafer W, held in a susceptor 170 inside the chamber 110, is irradiated with light from an upper heating section 150 and a lower heating section 140 by multiple VCSELs 45. The semiconductor wafer W heats up as it is irradiated with light from above and below.

[0093] By irradiating the semiconductor wafer W with light from above and below using multiple VCSEL45s, the semiconductor wafer W is heated at a rate of 100°C / second to 200°C / second. A few seconds after the start of light irradiation from the multiple VCSEL45s, the temperature of the semiconductor wafer W reaches its peak temperature T3. The peak temperature T3 is, for example, 900°C to 1000°C. When the temperature of the semiconductor wafer W reaches the peak temperature T3, the multiple VCSEL45s stop, and the temperature of the semiconductor wafer W rapidly decreases. Alternatively, the temperature of the semiconductor wafer W may be maintained at the peak temperature T3 for a certain period of time (for example, a few seconds).

[0094] In the fifth embodiment, the semiconductor wafer W is heated by light irradiation from the VCSEL45, which emits light of relatively high intensity compared to LEDs. Therefore, the semiconductor wafer W can be heated efficiently.

[0095] <Variation> While embodiments of the present invention have been described above, various modifications can be made to this invention without departing from its spirit. In the first embodiment, multiple VCSELs 45 were arranged in a concentric pattern, but the invention is not limited to this, and for example, multiple VCSELs 45 may be arranged in a grid pattern at equal intervals.

[0096] Furthermore, in the third and fourth embodiments, a homogenizer similar to that in the second embodiment may be provided above the multiple VCSELs 45 arranged in an annular shape. This makes it possible to make the illuminance distribution at the periphery of the semiconductor wafer W more uniform.

[0097] Furthermore, while the third and fourth embodiments involved arranging multiple VCSELs 45 in a ring shape around multiple LED lamps 47, the invention is not limited to this configuration. The VCSELs 45 can be positioned opposite the portion of the semiconductor wafer W where temperature drops are likely to occur during the heating process.

[0098] Furthermore, in the fifth embodiment, a heating section equipped with multiple VCSELs 45 may be provided only on either the upper or lower side of the chamber 110. Alternatively, a homogenizer, similar to that in the second embodiment, may be provided for the multiple VCSELs 45 in the fifth embodiment. Moreover, in the fifth embodiment, rapid heating of the semiconductor wafer W may be performed using multiple VCSELs 45 and multiple LED lamps, as in the third and fourth embodiments.

[0099] Furthermore, although the flash heating unit 5 is equipped with 30 flash lamps FL in the above embodiment, the number of flash lamps FL is not limited to this, and can be any number. Also, the flash lamps FL are not limited to xenon flash lamps, but may be krypton flash lamps. [Explanation of Symbols]

[0100] 1,1a,1b,100 Heat treatment apparatus 3. Control Unit 4 Auxiliary heating section 5. Flash heating section 6,110 chambers 7 Holding part 10 Transfer mechanism 20 Radiation thermometer 45 VCSEL 47 LED lamps 48 Homogenizer 48a Diffractive optical element 49 Power supply section 65 Heat treatment space 74,170 susceptors FL Flash Lamp W Semiconductor wafer

Claims

1. A heat treatment apparatus for heating a substrate by irradiating the substrate with light, A chamber for housing the circuit board, The chamber includes a holding portion for holding the substrate, An auxiliary light source is provided on one side of the chamber and irradiates light onto the substrate held in the holding portion, A flash lamp is provided on the other side of the chamber and irradiates the substrate held in the holding portion with flash light, Equipped with, The auxiliary light source comprises a plurality of vertical cavity type surface-emitting lasers, A homogenizer is further provided between the chamber and the auxiliary light source to homogenize the light emitted from each of the plurality of vertical cavity type surface-emitting lasers. The heat treatment apparatus is characterized in that the homogenizer is in the shape of a plate formed by bundling together optical elements of quartz rectangular prism members that correspond one-to-one with the plurality of vertical-cavity surface-emitting lasers.

2. In the heat treatment apparatus according to claim 1, The heat treatment apparatus is characterized in that the auxiliary light source includes a vertical-cavity surface-emitting laser that emits light of different wavelengths.

3. A heat treatment apparatus for heating a substrate by irradiating the substrate with light, A chamber for housing the circuit board, The chamber includes a holding portion for holding the substrate, An auxiliary light source is provided on one side of the chamber and irradiates light onto the substrate held in the holding portion, A flash lamp is provided on the other side of the chamber and irradiates the substrate held in the holding portion with flash light, Equipped with, The auxiliary light source comprises a plurality of vertical cavity surface-emitting lasers and a plurality of LED lamps. The heat treatment apparatus is characterized in that the plurality of vertical cavity type surface-emitting lasers are arranged in a ring with uniform density so as to surround the plurality of LED lamps which are arranged with uniform density in a circular region.

4. In the heat treatment apparatus according to claim 3, The heat treatment apparatus is characterized in that the auxiliary light source includes a vertical-cavity surface-emitting laser that emits light of different wavelengths and an LED lamp that emits light of different wavelengths.

5. In the heat treatment apparatus according to claim 3, The heat treatment apparatus is characterized in that the auxiliary light source further comprises an additional vertical-cavity surface-emitting laser provided at an angle around the plurality of vertical-cavity surface-emitting lasers arranged in a ring, such that the irradiation direction is directed toward the substrate held by the holding portion.

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