JP2013162010A - Heat treatment equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat treatment equipment capable of making in-plane temperature distribution of a substrate uniform.SOLUTION: In a heat treatment equipment, when a semiconductor wafer W is pre-heated, there exists nonuniformity in temperature distribution, with temperature of a peripheral part WS being lower than a central region. A laser beam entering from an incident side end 45b of a light guide rod 45 advances inside the quartz light guide rod 45 toward an exiting side end 45a cylindrically. The laser beam, that has arrived at the exiting side end 45a, is totally reflected on an inner sidewall surface of a conical recess 45c, and emitted toward the peripheral part WS of the semiconductor wafer W from an outer sidewall surface of the recess 45c. The laser beam at the center of the cylinder is totally reflected on an apex of the recess 45c and arrives at an edge WE of the semiconductor wafer W, and the laser beam at a side surface is totally reflected on a side surface of the recess 45c and arrives at an inner periphery of the peripheral part WS. As a result, the laser beam emitted from the light guide rod 45 is radiated in annular shape on the peripheral part WS of the semiconductor wafer W, thereby making in-plane temperature distribution of the wafer uniform.

Description

  The present invention relates to a heat treatment apparatus for heating a thin plate-shaped precision electronic substrate (hereinafter simply referred to as “substrate”) such as a semiconductor wafer or a glass substrate for a liquid crystal display device by irradiating flash light.

  In the semiconductor device manufacturing process, impurity introduction is an indispensable step for forming a pn junction in a semiconductor wafer. Currently, impurities are generally introduced by ion implantation and subsequent annealing. The ion implantation method is a technique in which impurity elements such as boron (B), arsenic (As), and phosphorus (P) are ionized and collided with a semiconductor wafer at a high acceleration voltage to physically perform impurity implantation. The implanted impurities are activated by annealing. At this time, if the annealing time is about several seconds or more, the implanted impurities are deeply diffused by heat, and as a result, the junction depth becomes deeper than required, and there is a possibility that good device formation may be hindered.

  Therefore, in recent years, flash lamp annealing (FLA) has attracted attention as an annealing technique for heating a semiconductor wafer in an extremely short time. Flash lamp annealing is a semiconductor wafer in which impurities are implanted by irradiating the surface of the semiconductor wafer with flash light using a xenon flash lamp (hereinafter, simply referred to as “flash lamp” means xenon flash lamp). Is a heat treatment technique for raising the temperature of only the surface of the material in a very short time (several milliseconds or less).

  The radiation spectral distribution of a xenon flash lamp ranges from the ultraviolet region to the near infrared region, has a shorter wavelength than the conventional halogen lamp, and almost coincides with the fundamental absorption band of a silicon semiconductor wafer. Therefore, when the semiconductor wafer is irradiated with flash light from the xenon flash lamp, the semiconductor wafer can be rapidly heated with little transmitted light. Further, it has been found that if the flash light irradiation is performed for a very short time of several milliseconds or less, only the vicinity of the surface of the semiconductor wafer can be selectively heated. For this reason, if the temperature is raised for a very short time by the xenon flash lamp, only the impurity activation can be performed without deeply diffusing the impurities.

  As a heat treatment apparatus using such a xenon flash lamp, in Patent Documents 1 and 2, a pulse emitting lamp such as a flash lamp is arranged on the front side of a semiconductor wafer, and a continuous lighting lamp such as a halogen lamp is arranged on the back side. And what performs desired heat processing by those combination is disclosed. In the heat treatment apparatuses disclosed in Patent Documents 1 and 2, the semiconductor wafer is preheated to a certain temperature with a halogen lamp or the like, and then heated to a desired processing temperature by pulse heating from a flash lamp. Patent Document 3 discloses an apparatus for placing a semiconductor wafer on a hot plate, preheating it to a predetermined temperature, and then raising the temperature to a desired processing temperature by flash light irradiation from a flash lamp. .

JP-A-60-258928 JP 2005-527972 A JP 2007-5532 A

  When preheating a semiconductor wafer with a hot plate as disclosed in Patent Document 3, the in-plane distribution of the wafer temperature can be made relatively uniform by accurately adjusting the plate temperature. In particular, the hot plate of Patent Document 3 is concentrically divided into a plurality of zones, and the temperature can be adjusted for each zone, so that the in-plane distribution of the wafer temperature can be easily made uniform. On the other hand, when preheating is performed with a halogen lamp as disclosed in Patent Documents 1 and 2, the process merit that the semiconductor wafer can be heated to a relatively high preheating temperature in a short time. However, the temperature at the peripheral edge of the wafer tends to be lower than that at the center.

  In order to eliminate the temperature drop at the peripheral edge in the preliminary heating stage with such a halogen lamp, increasing the amount of light irradiated from the halogen lamp to the wafer peripheral edge increases the temperature of a part of the peripheral edge. The uniformity of temperature distribution in the inner region than the peripheral edge will be impaired. Moreover, the temperature drop at the outermost edge of the semiconductor wafer remains without being fully eliminated.

  The present invention has been made in view of the above problems, and an object thereof is to provide a heat treatment apparatus capable of making the in-plane temperature distribution of a substrate uniform.

  In order to solve the above-mentioned problems, a first aspect of the present invention provides a heat treatment apparatus for heating a disk-shaped substrate by irradiating flash light on the disk-shaped substrate. Holding means for holding the substrate, a flash lamp for irradiating the surface of the substrate held by the holding means with flash light, and preheating for preheating the substrate to a predetermined temperature before irradiating the flash light from the flash lamp Means, and auxiliary irradiation means for irradiating laser light in a ring shape on the peripheral edge of the back surface of the substrate.

  The invention according to claim 2 is the heat treatment apparatus according to claim 1, wherein the auxiliary irradiation means is a rod-like member provided so as to extend along the longitudinal direction of the central axis of the substrate held by the holding means. A light guide rod; and laser light emitting means for making a laser beam incident from an incident side end far from the substrate held by the holding means among both ends of the light guide rod, and the incident side end The laser light incident from the light travels in a cylindrical shape inside the light guide rod toward the output side end, and the holding means extends from the inside of the light guide rod to the output side end of the light guide rod. A conical recess having a large opening diameter is formed toward the substrate held on the substrate.

  According to a third aspect of the present invention, in the heat treatment apparatus according to the second aspect of the present invention, a metal film is formed on the wall surface of the conical recess.

  According to a fourth aspect of the present invention, in the heat treatment apparatus according to the second aspect of the invention, the auxiliary irradiating means further includes a metal body that fits into the conical recess.

  The invention according to claim 5 is the heat treatment apparatus according to any one of claims 2 to 4, further comprising a slide drive unit that reciprocates the light guide rod along the central axis. And

  The invention according to claim 6 is the heat treatment apparatus according to claim 5, wherein the cylinder formed by the laser light guided inside the light guide rod has a continuous strength from the center of the cylinder toward the periphery. And the center of the slide drive unit is held so that the laser beam located at the center of the cylinder is held by the holding means. The light guide rod is moved to a position reaching the edge of the substrate.

  The invention according to claim 7 is the heat treatment apparatus according to any one of claims 2 to 6, further comprising a rotation drive unit that rotates the light guide rod about the central axis. And

  The invention according to claim 8 is the heat treatment apparatus according to claim 1, wherein the auxiliary irradiating means is a rod-like member provided so as to extend along the longitudinal direction of the central axis of the substrate held by the holding means. A light guide rod; and laser light emitting means for making a laser beam incident from an incident side end far from the substrate held by the holding means among both ends of the light guide rod, and the incident side end The laser light incident from the light travels in a cylindrical shape inside the light guide rod toward the output side end, and the holding means extends from the inside of the light guide rod to the output side end of the light guide rod. A conical axicon lens having a smaller diameter toward the substrate held by the substrate is attached.

  The invention according to claim 9 is the heat treatment apparatus according to any one of claims 1 to 8, wherein the preliminary heating means is a halogen lamp that irradiates the back surface of the substrate held by the holding means. It is characterized by providing.

  According to the first to ninth aspects of the present invention, since the auxiliary irradiation means for irradiating the laser beam in an annular shape is provided on the peripheral edge of the back surface of the substrate, the temperature non-uniformity generated in the peripheral edge of the substrate during preheating is eliminated. The in-plane temperature distribution of the substrate can be made uniform.

  In particular, according to the invention of claim 3, since the metal film is formed on the wall surface of the conical recess, leakage of the laser beam on the wall surface of the recess can be prevented.

  In particular, according to the invention of claim 4, since the metal body fitted into the conical recess is provided, leakage of the laser beam on the wall surface of the recess can be prevented.

  In particular, according to the invention of claim 5, since the slide drive unit that reciprocates the light guide rod along the central axis of the substrate is provided, the position of the annular laser light irradiation region at the peripheral edge of the back surface of the substrate can be adjusted. At the same time, the diameter of the laser light irradiation region can be enlarged and reduced.

  In particular, according to the invention of claim 6, the cylinder formed by the laser light guided inside the light guide rod has an intensity distribution in which the intensity continuously decreases from the center to the periphery of the cylinder, The center of the slide advances so that the center reaches the apex of the conical recess, and the slide drive unit moves the light guide rod to a position where the laser beam located at the center of the cylinder reaches the edge of the substrate. The edge portion of the substrate having the lowest temperature during heating is irradiated with the strongest laser beam, and the in-plane temperature distribution of the substrate can be made uniform with higher accuracy.

  In particular, according to the seventh aspect of the present invention, since the light guide rod is provided with the rotation driving unit for rotating the light guide rod about the central axis of the substrate, even if a slight deviation occurs between the laser light irradiation region and the substrate peripheral portion. The in-plane temperature distribution of the substrate can be made uniform.

  In particular, according to the invention of claim 9, since the preheating means includes the halogen lamp, the in-plane temperature distribution of the substrate caused by light irradiation from the halogen lamp can be eliminated.

It is a longitudinal cross-sectional view which shows the structure of the heat processing apparatus which concerns on this invention. It is a perspective view which shows the whole external appearance of a holding | maintenance part. It is the top view which looked at the holding | maintenance part from the upper surface. It is the side view which looked at the holding | maintenance part from the side. It is a top view of a transfer mechanism. It is a side view of a transfer mechanism. It is a figure which shows the drive circuit of a flash lamp. It is a top view which shows arrangement | positioning of a some halogen lamp. It is a figure which shows the structure of an auxiliary irradiation part. It is a perspective view of a light guide rod. It is a figure which shows the optical path of the laser beam in a light guide rod. It is a figure which shows the irradiation area | region of the laser beam in the main surface of a semiconductor wafer. It is a figure which shows an example of the intensity distribution in the cylinder formed with the laser beam which advances the inside of a light guide rod. It is a figure which shows the correlation of the radial direction temperature distribution of the semiconductor wafer at the time of preheating, and the laser beam intensity distribution in a peripheral part. It is a longitudinal cross-sectional view which shows the structure of the light guide rod of 2nd Embodiment. It is a longitudinal cross-sectional view which shows the structure of the light guide rod of 3rd Embodiment. It is a figure which shows the light guide rod of 4th Embodiment. It is a figure which shows the laser beam irradiation in 5th Embodiment. It is a figure which shows the laser beam irradiation in 6th Embodiment.

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

<First Embodiment>
FIG. 1 is a longitudinal sectional view showing a 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 semiconductor wafer W by irradiating flash light onto a disk-shaped semiconductor wafer W having a diameter of 300 mm as a substrate. Impurities are implanted into the semiconductor wafer W before being carried into the heat treatment apparatus 1, and an activation process of the impurities implanted by the heat treatment by the heat treatment apparatus 1 is executed. In FIG. 1 and the subsequent drawings, the size and number of each part are exaggerated or simplified as necessary for easy understanding.

  The heat treatment apparatus 1 includes a chamber 6 that accommodates a semiconductor wafer W, a flash heating unit 5 that houses a plurality of flash lamps FL, a halogen heating unit 4 that houses a plurality of halogen lamps HL, and a shutter mechanism 2. . A flash heating unit 5 is provided on the upper side of the chamber 6, and a halogen heating unit 4 is provided on the lower side. The heat treatment apparatus 1 includes a holding unit 7 that holds the semiconductor wafer W in a horizontal posture inside the chamber 6, and a transfer mechanism 10 that transfers the semiconductor wafer W between the holding unit 7 and the outside of the apparatus, Is provided. Further, the heat treatment apparatus 1 includes a control unit 3 that controls the operation mechanisms provided in the shutter mechanism 2, the halogen heating unit 4, the flash heating unit 5, and the chamber 6 to perform the heat treatment of the semiconductor wafer W.

  The chamber 6 is configured by mounting quartz chamber windows above and below a cylindrical chamber side portion 61. The chamber side portion 61 has a substantially cylindrical shape with upper and lower openings. The upper opening is closed by an upper chamber window 63 and the lower opening is closed by a lower chamber window 64. ing. The upper chamber window 63 constituting the ceiling of the chamber 6 is a disk-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 constituting the floor portion of the chamber 6 is also a disk-shaped member made of quartz and functions as a quartz window that transmits light from the halogen heating unit 4 into the chamber 6.

  A reflection ring 68 is attached to the upper part of the inner wall surface of the chamber side part 61, and a reflection ring 69 is attached to the lower part. The reflection rings 68 and 69 are both formed in an annular shape. The upper reflecting ring 68 is attached by fitting from above the chamber side portion 61. On the other hand, the lower reflection ring 69 is mounted by being fitted from the lower side of the chamber side portion 61 and fastened with a screw (not shown). That is, the reflection rings 68 and 69 are both detachably attached to the chamber side portion 61. An inner space of the chamber 6, that is, a space surrounded by the upper chamber window 63, the lower chamber window 64, the chamber side portion 61, and the reflection rings 68 and 69 is defined as a heat treatment space 65.

  By attaching the reflection rings 68 and 69 to the chamber side portion 61, a recess 62 is formed on the inner wall surface of the chamber 6. That is, a recess 62 surrounded by a central portion of the inner wall surface of the chamber side portion 61 where the reflection rings 68 and 69 are not mounted, a lower end surface of the reflection ring 68, and an upper end surface of the reflection ring 69 is formed. . 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 reflection rings 68 and 69 are formed of a metal material (for example, stainless steel) having excellent strength and heat resistance. Further, the inner peripheral surfaces of the reflection rings 68 and 69 are mirrored by electrolytic nickel plating.

  The chamber side 61 is formed with a transfer opening (furnace port) 66 for carrying the semiconductor wafer W into and out of the chamber 6. The transfer opening 66 can be opened and closed by a gate valve 185. The transport opening 66 is connected to the outer peripheral surface of the recess 62. Therefore, when the gate valve 185 opens the transfer opening 66, the semiconductor wafer W is carried into the heat treatment space 65 through the recess 62 from the transfer opening 66 and the semiconductor wafer W is carried out from the heat treatment space 65. It can be performed. Further, when the gate valve 185 closes the transfer opening 66, the heat treatment space 65 in the chamber 6 becomes a sealed space.

Further, a gas supply hole 81 for supplying a processing gas (nitrogen gas (N ₂ ) in the present embodiment) to the heat treatment space 65 is formed in the upper portion of the inner wall of the chamber 6. The gas supply hole 81 is formed at a position above the recess 62 and may be provided in the reflection ring 68. The gas supply hole 81 is connected to a gas supply pipe 83 through 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 middle of the path of 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 flowing into the buffer space 82 flows so as to expand in the buffer space 82 having a smaller fluid resistance than the gas supply hole 81 and is supplied from the gas supply hole 81 into the heat treatment space 65.

  On the other hand, a gas exhaust hole 86 for exhausting the gas in the heat treatment space 65 is formed in the lower portion of the inner wall of the chamber 6. The gas exhaust hole 86 is formed at a position lower than the recess 62 and may be provided in the reflection ring 69. The gas exhaust hole 86 is connected to a gas exhaust pipe 88 through 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 unit 190. A valve 89 is inserted in the middle of the path of the gas exhaust pipe 88. When the valve 89 is opened, the gas in the heat treatment space 65 is discharged from the gas exhaust hole 86 to the gas exhaust pipe 88 through the buffer space 87. A plurality of gas supply holes 81 and gas exhaust holes 86 may be provided along the circumferential direction of the chamber 6 or may be slit-shaped. Further, the nitrogen gas supply source 85 and the exhaust unit 190 may be a mechanism provided in the heat treatment apparatus 1 or may be a utility of a factory where the heat treatment apparatus 1 is installed.

  A gas exhaust pipe 191 that exhausts the gas in the heat treatment space 65 is also connected to the tip of the transfer opening 66. The gas exhaust pipe 191 is connected to the exhaust unit 190 via a valve 192. By opening the valve 192, the gas in the chamber 6 is exhausted through the transfer opening 66.

  FIG. 2 is a perspective view showing the overall appearance of the holding unit 7. FIG. 3 is a plan view of the holding unit 7 as viewed from above, and FIG. 4 is a side view of the holding unit 7 as viewed from the side. The holding part 7 includes a base ring 71, a connecting part 72, and a susceptor 74. The base ring 71, the connecting portion 72, and the susceptor 74 are all made of quartz. That is, the whole holding part 7 is made of quartz.

  The base ring 71 is an annular quartz member. The base ring 71 is supported on the wall surface of the chamber 6 by being placed on the bottom surface of the recess 62 (see FIG. 1). On the upper surface of the base ring 71 having an annular shape, a plurality of connecting portions 72 (four in this embodiment) are erected along the circumferential direction. The connecting portion 72 is also a quartz member, and is fixed to the base ring 71 by welding. The shape of the base ring 71 may be an arc shape in which a part is omitted from the annular shape.

  The flat susceptor 74 is supported by four connecting portions 72 provided on the base ring 71. The susceptor 74 is a substantially circular flat plate member made of quartz. The diameter of the susceptor 74 is larger than the diameter of the semiconductor wafer W. That is, the susceptor 74 has a larger planar size than the semiconductor wafer W. On the upper surface of the susceptor 74, a plurality (five in this embodiment) of guide pins 76 are erected. The five guide pins 76 are provided along a circumference that is concentric with the outer circumference of the susceptor 74. The diameter of the circle in which the five guide pins 76 are arranged is slightly larger than the diameter of the semiconductor wafer W. Each guide pin 76 is also formed of quartz. The guide pin 76 may be processed from a quartz ingot integrally with the susceptor 74, or a separately processed one may be attached to the susceptor 74 by welding or the like.

  The four connecting portions 72 erected on the base ring 71 and the lower surface of the peripheral portion of the susceptor 74 are fixed by welding. That is, the susceptor 74 and the base ring 71 are fixedly connected by the connecting portion 72, and the holding portion 7 is an integrally formed member of quartz. When the base ring 71 of the holding unit 7 is supported on the wall surface of the chamber 6, the holding unit 7 is attached to the chamber 6. In a state in which the holding unit 7 is mounted on the chamber 6, the substantially disc-shaped susceptor 74 is in a horizontal posture (a posture in which the normal line matches the vertical direction). The semiconductor wafer W carried into the chamber 6 is placed and held in a horizontal posture on the susceptor 74 of the holding unit 7 attached to the chamber 6. The semiconductor wafer W is placed inside a circle formed by the five guide pins 76, thereby preventing a horizontal displacement. Note that the number of guide pins 76 is not limited to five, and may be any number that can prevent misalignment of the semiconductor wafer W.

  As shown in FIGS. 2 and 3, the susceptor 74 has an opening 78 and a notch 77 penetrating vertically. The notch 77 is provided to pass the probe tip of the contact thermometer 130 using a thermocouple. On the other hand, the opening 78 is provided to receive radiation light (infrared light) emitted from the lower surface of the semiconductor wafer W held by the susceptor 74 by the radiation thermometer 120. Further, the susceptor 74 is provided with four through holes 79 through which lift pins 12 of the transfer mechanism 10 to be described later penetrate for the delivery of the semiconductor wafer W.

  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 arm 11 has an arc shape that follows the generally annular recess 62. Two lift pins 12 are erected on each transfer arm 11. Each transfer arm 11 can be rotated by a horizontal movement mechanism 13. The horizontal movement mechanism 13 includes a transfer operation position (a position indicated by a solid line in FIG. 5) for transferring the pair of transfer arms 11 to the holding unit 7 and the semiconductor wafer W held by the holding unit 7. It is moved horizontally between the retracted positions (two-dot chain line positions in FIG. 5) that do not overlap in plan view. As the horizontal movement mechanism 13, each transfer arm 11 may be rotated by an individual motor, or a pair of transfer arms 11 may be interlocked by a single motor using a link mechanism. It may be moved.

  The pair of transfer arms 11 are moved up and down together with the horizontal moving mechanism 13 by the lifting mechanism 14. When the elevating mechanism 14 raises the pair of transfer arms 11 at 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 lift pins The upper end of 12 protrudes from the upper surface of the susceptor 74. On the other hand, when the elevating mechanism 14 lowers the pair of transfer arms 11 at the transfer operation position, the lift pins 12 are extracted from the through holes 79, and the horizontal movement mechanism 13 moves the pair of transfer arms 11 so as to open each of them. The transfer arm 11 moves to the retracted position. The retracted position of the pair of transfer arms 11 is directly above the base ring 71 of the holding unit 7. Since the base ring 71 is placed on the bottom surface of the recess 62, the retracted position of the transfer arm 11 is inside the recess 62. Note that an exhaust mechanism (not shown) is also provided in the vicinity of a portion where the drive unit (the horizontal movement mechanism 13 and the lifting mechanism 14) of the transfer mechanism 10 is provided, and the atmosphere around the drive unit of the transfer mechanism 10 is provided. Is discharged to the outside of the chamber 6.

  Returning to FIG. 1, the flash heating unit 5 provided above the chamber 6 includes a light source including a plurality of (30 in the present embodiment) xenon flash lamps FL inside the housing 51, and an upper part of the light source. And a reflector 52 provided so as to cover. A lamp light emission window 53 is mounted on the bottom of the casing 51 of the flash heating unit 5. The lamp light emission window 53 constituting the floor of the flash heating unit 5 is a plate-like 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 lamp FL irradiates 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.

  Each of the plurality of flash lamps FL is a rod-shaped lamp having a long cylindrical shape, and the longitudinal direction of each of the flash lamps FL is along the main surface of the semiconductor wafer W held by the holding unit 7 (that is, along the horizontal direction). They are arranged in a plane so as to be parallel to each other. Therefore, the plane formed by the arrangement of the flash lamps FL is also a horizontal plane.

  FIG. 7 is a diagram showing a driving circuit for the flash lamp FL. As shown in the figure, a capacitor 93, a coil 94, a flash lamp FL, and an IGBT (insulated gate bipolar transistor) 96 are connected in series. As shown in FIG. 7, the control unit 3 includes a pulse generator 31 and a waveform setting unit 32 and is connected to the input unit 33. As the input unit 33, various known input devices such as a keyboard, a mouse, and a touch panel can be employed. The waveform setting unit 32 sets the waveform of the pulse signal based on the input content from the input unit 33, and the pulse generator 31 generates the pulse signal according to the waveform.

  The flash lamp FL includes a rod-shaped glass tube (discharge tube) 92 in which xenon gas is sealed and an anode and a cathode are disposed at both ends thereof, and a trigger electrode provided on the outer peripheral surface of the glass tube 92. 91. A predetermined voltage is applied to the capacitor 93 by the power supply unit 95, and a charge corresponding to the applied voltage (charging voltage) is charged. A high voltage can be applied to the trigger electrode 91 from the trigger circuit 97. The timing at which the trigger circuit 97 applies a voltage to the trigger electrode 91 is controlled by the control unit 3.

  The IGBT 96 is a bipolar transistor in which a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) is incorporated in a gate portion, and is a switching element suitable for handling high power. A pulse signal is applied from the pulse generator 31 of the control unit 3 to the gate of the IGBT 96. The IGBT 96 is turned on when a voltage higher than a predetermined value (High voltage) is applied to the gate of the IGBT 96, and the IGBT 96 is turned off when a voltage lower than the predetermined value (Low voltage) is applied. In this way, the drive circuit including the flash lamp FL is turned on / off by the IGBT 96. When the IGBT 96 is turned on / off, the connection between the flash lamp FL and the corresponding capacitor 93 is interrupted.

  Even if the IGBT 96 is turned on while the capacitor 93 is charged and a high voltage is applied to both end electrodes of the glass tube 92, the xenon gas is electrically an insulator, so that the glass is normal in the state. No electricity flows in the tube 92. However, when the trigger circuit 97 applies a high voltage to the trigger electrode 91 to break the insulation, an electric current instantaneously flows in the glass tube 92 due to the discharge between the both end electrodes, and excitation of the xenon atoms or molecules at that time Emits light.

  Further, the reflector 52 of FIG. 1 is provided above the plurality of flash lamps FL so as to cover all of them. The basic function of the reflector 52 is to reflect the light emitted from the plurality of flash lamps FL toward the holding unit 7. The reflector 52 is formed of an aluminum alloy plate, and the surface (the surface facing the flash lamp FL) is roughened by blasting to exhibit a satin pattern.

  A plurality of halogen lamps HL (40 in this embodiment) are built in the halogen heating unit 4 provided below the chamber 6. The plurality of halogen lamps HL irradiate the heat treatment space 65 from below the chamber 6 through the lower chamber window 64. FIG. 8 is a plan view showing the arrangement of a plurality of halogen lamps HL. In the present embodiment, 20 halogen lamps HL are arranged in two upper and lower stages. Each halogen lamp HL is a rod-shaped lamp having a long cylindrical shape. The 20 halogen lamps HL in both the upper and lower stages are arranged so that their longitudinal directions are parallel to each other along the main surface of the semiconductor wafer W held by the holding unit 7 (that is, along the horizontal direction). Yes. Therefore, the plane formed by the arrangement of the halogen lamps HL in both the upper stage and the lower stage is a horizontal plane.

  Further, as shown in FIG. 8, the arrangement density of the halogen lamps HL in the region facing the peripheral portion is higher than the region facing the central portion of the semiconductor wafer W held by the holding portion 7 in both the upper and lower steps. Yes. That is, in both the upper and lower stages, the arrangement pitch of the halogen lamps HL is shorter on the end side than on the center part of the lamp array. For this reason, it is possible to irradiate a larger amount of light to the peripheral portion of the semiconductor wafer W where the temperature is likely to decrease during heating by light irradiation from the halogen heating unit 4.

  Further, the lamp group composed of the upper halogen lamp HL and the lamp group composed of the lower halogen lamp HL are arranged so as to intersect in a lattice pattern. That is, a total of 40 halogen lamps HL are arranged so that the longitudinal direction of the upper halogen lamps HL and the longitudinal direction of the lower halogen lamps HL are orthogonal to each other.

  The halogen lamp HL is a filament-type light source that emits light by making the filament incandescent by energizing the filament disposed inside the glass tube. Inside the glass tube, a gas obtained by introducing a trace amount of a halogen element (iodine, bromine, etc.) into an inert gas such as nitrogen or argon is enclosed. By introducing a halogen element, it is possible to set the filament temperature to a high temperature while suppressing breakage of the filament. Therefore, the halogen lamp HL has a characteristic that it has a longer life than a normal incandescent bulb and can continuously radiate strong light. Further, since the halogen lamp HL is a rod-shaped lamp, it has a long life, and by arranging the halogen lamp HL along the horizontal direction, the radiation efficiency to the upper semiconductor wafer W becomes excellent.

  Further, as shown in FIG. 1, an auxiliary irradiation unit 40 is provided below the holding unit 7. FIG. 9 is a diagram illustrating a configuration of the auxiliary irradiation unit 40. In FIG. 9, for convenience of illustration, the configurations of the halogen heating unit 4 and the chamber 6 are simplified. The auxiliary irradiation unit 40 includes a laser beam emitting unit 44 and a light guide rod 45 as main elements. The laser beam emitting unit 44 includes a laser unit 41, an optical fiber 42, and a lens 43. The laser unit 41 of this embodiment is a very high-power semiconductor laser with an output of 80 W to 500 W, and emits a visible light laser with a wavelength of 800 nm to 820 nm. Laser light emitted from the laser unit 41 is guided to the lens 43 by the optical fiber 42. Then, the laser light emitted from the lens 43 enters the light guide rod 45.

  FIG. 10 is a perspective view of the light guide rod 45. The light guide rod 45 is a substantially cylindrical (bar-shaped) optical member made of quartz. In the present embodiment, the diameter of the cylindrical shape of the light guide rod 45 is φ15 mm, but the diameter is not limited to this and can be any diameter. Quartz transmits laser light having a wavelength emitted from the laser light emitting unit 44. The light guide rod 45 is disposed immediately below the center of the semiconductor wafer W held by the holding unit 7. Specifically, the light guide rod 45 is provided in a standing posture so that the longitudinal direction of the columnar shape is along the central axis CX of the semiconductor wafer W held by the holding unit 7. That is, the cylindrical central axis of the light guide rod 45 coincides with the central axis CX of the semiconductor wafer W. The central axis CX is a central axis perpendicular to the main surface of the semiconductor wafer W held by the holding unit 7.

  Of the both ends of the cylindrical light guide rod 45, the upper side (side closer to the semiconductor wafer W held by the holding unit 7) is the emission side end 45a, and the lower side (semiconductor wafer W held by the holding unit 7). The incident side end 45b is a side far from the side. The lens 43 of the laser beam emitting portion 44 is disposed at a position facing the incident side end portion 45b. As shown in FIG. 10, the incident side end 45b at the lower end is a flat surface, but the conical recess 45c is formed at the emission side end 45a at the upper end. The central axis of the conical shape of the recess 45 c coincides with the central axis CX of the semiconductor wafer W. Further, the conical shape of the recess 45 c has an opening diameter that increases from the inside of the light guide rod 45 toward the semiconductor wafer W held by the holding unit 7.

  As shown in FIG. 9, the upper side of the light guide rod 45 passes through the bottom wall of the halogen heating unit 4 and a reflector for the halogen lamp HL (not shown). You may make it provide the bearing for a seal | sticker in the site | part through which the light guide rod 45 penetrates the bottom wall of the halogen heating part 4. FIG. The light guide rod 45 further passes through the gap in the arrangement of the halogen lamps HL (see FIG. 8), and the emission side end 45a is provided at least above the upper halogen lamp HL. For this reason, even when the light guide rod 45 rotates, the contact between the light guide rod 45 and the halogen lamp HL is prevented.

  FIG. 11 is a diagram illustrating an optical path of laser light in the light guide rod 45. The laser light emitted from the laser light emitting portion 44 and perpendicularly incident on the incident side end portion 45b which is a flat surface travels straight along the longitudinal direction of the light guide rod 45 provided along the vertical direction. The laser beam incident from the lower incident side end 45b travels in a cylindrical shape inside the quartz light guide rod 45 toward the upper emission side end 45a. The diameter of the cylinder formed by the laser light traveling inside the light guide rod 45 is φ6 mm to φ20 mm (φ6 mm in this embodiment), and can be adjusted by the lens 43. In addition, the central axis of the cylinder formed by the laser light guided inside the light guide rod 45 coincides with the central axis of the light guide rod 45 (that is, the central axis CX of the semiconductor wafer W).

  As shown in FIG. 11, the laser light that has reached the emission side end 45a is totally reflected by the inner wall surface (conical side surface) of the recess 45c, and the outer wall surface (of the light guide rod 45 of the light guide rod 45). The light is emitted from the side wall surface toward the peripheral edge WS of the semiconductor wafer W held by the holding portion 7. The laser beam is slightly refracted when it is emitted from the emission side end 45a of quartz into the atmosphere.

  The center of the cylinder formed by the laser light guided inside the light guide rod 45 reaches the apex of the conical shape of the recess 45c. The laser beam totally reflected at the apex of the recess 45 c is emitted from the emission side end 45 a and reaches the edge WE of the semiconductor wafer W held by the holding unit 7.

  On the other hand, the side surface of the cylinder formed by the laser light reaches a predetermined position (position between the apex and the bottom surface) of the conical side surface of the recess 45c. Then, the laser beam totally reflected at the predetermined position is emitted from the emission side end portion 45a and reaches the inner circumference of the peripheral edge WS of the semiconductor wafer W.

  Here, the peripheral edge WS of the semiconductor wafer W is a region from the outermost periphery of the disk-shaped semiconductor wafer W to a concentric circle having a shorter diameter, and is a ring-shaped region having a predetermined width. Moreover, the edge part WE of the semiconductor wafer W is the outermost peripheral part of the disk-shaped semiconductor wafer W.

  FIG. 12 is a view showing an irradiation region of the laser beam on the main surface of the semiconductor wafer W. In the figure, the laser beam irradiation region is hatched. The laser beam guided in a cylindrical shape toward the emission side end 45a from the inside of the light guide rod 45 is totally reflected by the inner side surface of the conical recess 45c, whereby the laser emitted from the emission side end 45a. The light is irradiated in a ring shape on the peripheral edge WS of the semiconductor wafer W held by the holding unit 7.

  In addition, the auxiliary irradiation unit 40 includes a slide drive unit 47 that slides the light guide rod 45 along the central axis CX of the semiconductor wafer W. As the slide drive unit 47, for example, a pulse motor that rotates a ball screw screwed to a member connected to the light guide rod 45 can be used. When the slide drive unit 47 raises the light guide rod 45 (closer to the semiconductor wafer W), the diameter of the annular laser light irradiation region on the main surface of the semiconductor wafer W is reduced, as is apparent from FIGS. . Conversely, when the slide drive unit 47 lowers the light guide rod 45 (away from the semiconductor wafer W), the diameter of the annular laser light irradiation region on the main surface of the semiconductor wafer W increases.

  In the first embodiment, the inside of the light guide rod 45 is more specifically guided so that the annular laser light irradiation region on the main surface of the semiconductor wafer W coincides with the peripheral edge WS of the semiconductor wafer W. The slide drive unit 47 adjusts the height position of the light guide rod 45 so that the light at the center of the cylinder formed by the laser light reaches the edge portion WE of the semiconductor wafer W. For such adjustment, an encoder that detects the height position of the light guide rod 45 from the rotation angle of the pulse motor may be attached to the slide drive unit 47.

  Further, the auxiliary irradiation unit 40 includes a rotation driving unit 46 that rotates the light guide rod 45 about the central axis CX of the semiconductor wafer W as a rotation center. As the rotation drive unit 46, for example, a hollow motor having a hollow motor shaft can be used, and the lower side of the light guide rod 45 is inserted into the hollow portion.

  Returning to FIG. 1, the heat treatment apparatus 1 includes a shutter mechanism 2 on the side of the halogen heating unit 4 and the chamber 6. The shutter mechanism 2 includes a shutter plate 21 and a slide drive mechanism 22. The shutter plate 21 is a plate that is opaque to the halogen light, and is formed of, for example, titanium (Ti). The slide drive mechanism 22 slides the shutter plate 21 along the horizontal direction, and inserts and removes the shutter plate 21 to and from the light shielding position between the halogen heating unit 4 and the holding unit 7. When the slide drive mechanism 22 advances the shutter plate 21, the shutter plate 21 is inserted into the light shielding position (the two-dot chain line position in FIG. 1) between the chamber 6 and the halogen heating unit 4, and the lower chamber window 64 and the plurality of lower chamber windows 64. The halogen lamp HL is cut off. Accordingly, light traveling from the plurality of halogen lamps HL toward the holding portion 7 of the heat treatment space 65 is shielded. Conversely, when the slide drive mechanism 22 retracts the shutter plate 21, the shutter plate 21 retracts from the light shielding position between the chamber 6 and the halogen heating unit 4 and the lower portion of the lower chamber window 64 is opened. The light guide rod 45 is installed such that the height position of the emission side end 45 a is below the light shielding position of the shutter plate 21. For this reason, the light guide rod 45 does not become an obstacle to the forward / backward movement of the shutter plate 21.

  Further, the control unit 3 controls the various operation mechanisms provided in the heat treatment apparatus 1. The configuration of the control unit 3 as hardware is the same as that of a general computer. That is, the control unit 3 stores a CPU that performs various arithmetic processes, a ROM that is a read-only memory that stores basic programs, a RAM that is a readable and writable memory that stores various information, control software, data, and the like. It is configured with a magnetic disk. The processing in the heat treatment apparatus 1 proceeds as the CPU of the control unit 3 executes a predetermined processing program. As shown in FIG. 7, the control unit 3 includes a pulse generator 31 and a waveform setting unit 32. As described above, the waveform setting unit 32 sets the waveform of the pulse signal based on the input content from the input unit 33, and the pulse generator 31 outputs the pulse signal to the gate of the IGBT 96 in accordance therewith.

  In addition to the above configuration, the heat treatment apparatus 1 prevents an excessive temperature rise in the halogen heating unit 4, the flash heating unit 5, and the chamber 6 due to thermal energy generated from the halogen lamp HL and the flash lamp FL during the heat treatment of the semiconductor wafer W. Therefore, various cooling structures are provided. For example, the wall of the chamber 6 is provided with a water-cooled tube (not shown). Further, the halogen heating unit 4 and the flash heating unit 5 have an air cooling structure in which a gas flow is formed inside to exhaust 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 the upper chamber window 63.

  Next, a processing procedure for the 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) are added by an ion implantation method. The activation of the impurities is performed by flash light irradiation heat treatment (annealing) by the heat treatment apparatus 1. The processing procedure of the heat treatment apparatus 1 described below proceeds by the control unit 3 controlling each operation mechanism of the heat treatment apparatus 1.

  First, the air supply valve 84 is opened, and the exhaust valves 89 and 192 are opened to start supply and exhaust of air into the chamber 6. When the valve 84 is opened, nitrogen gas is supplied from the gas supply hole 81 to the heat treatment space 65. When the valve 89 is opened, the gas in the chamber 6 is exhausted from the gas exhaust hole 86. Thereby, the nitrogen gas supplied from the upper part of the heat treatment space 65 in the chamber 6 flows downward and is exhausted from the lower part of the heat treatment space 65.

  Further, when the valve 192 is opened, the gas in the chamber 6 is also exhausted from the transfer opening 66. Further, the atmosphere around the drive unit of the transfer mechanism 10 is also exhausted by an exhaust mechanism (not shown). Note that nitrogen gas is continuously supplied to the heat treatment space 65 during the heat treatment of the semiconductor wafer W in the heat treatment apparatus 1, and the supply amount is appropriately changed according to the treatment process.

  Subsequently, the gate valve 185 is opened to open the transfer opening 66, and the semiconductor wafer W after ion implantation is transferred into the heat treatment space 65 in the chamber 6 through the transfer opening 66 by a transfer robot outside the apparatus. The semiconductor wafer W carried in by the carrying robot advances to a position directly above the holding unit 7 and stops. Then, when the pair of transfer arms 11 of the transfer mechanism 10 moves horizontally from the retracted position to the transfer operation position and rises, the lift pins 12 protrude from the upper surface of the susceptor 74 through the through holes 79 and the semiconductor wafer W. Receive.

  After the semiconductor wafer W is placed on the lift pins 12, the transfer robot leaves the heat treatment space 65 and the transfer opening 66 is closed by the gate valve 185. When the pair of transfer arms 11 are lowered, the semiconductor wafer W is transferred from the transfer mechanism 10 to the susceptor 74 of the holding unit 7 and held from below in a horizontal posture. The semiconductor wafer W is held by the holding unit 7 with the surface on which the pattern is formed and impurities are implanted as the upper surface. The semiconductor wafer W is held inside the five guide pins 76 on the upper surface of the susceptor 74. The pair of transfer arms 11 lowered to below the susceptor 74 is retracted to the retracted position, that is, inside the recess 62 by the horizontal movement mechanism 13.

  After the semiconductor wafer W is held horizontally from below by the holding unit 7 made of quartz, the 40 halogen lamps HL of the halogen heating unit 4 are turned on all at once and preheating (assist heating) is started. Is done. The halogen light emitted from the halogen lamp HL passes through the lower chamber window 64 and the susceptor 74 made of quartz and is irradiated from the back surface (main surface opposite to the front surface) of the semiconductor wafer W. By receiving light from the halogen lamp HL, the semiconductor wafer W is preheated and the temperature rises. In addition, since the transfer arm 11 of the transfer mechanism 10 is retracted to the inside of the recess 62, there is no obstacle to heating by the halogen lamp HL.

  When preheating with the halogen lamp HL is performed, the temperature of the semiconductor wafer W is measured by the contact thermometer 130. That is, a contact thermometer 130 incorporating a thermocouple contacts the lower surface of the semiconductor wafer W held by the holding unit 7 via the notch 77 of the susceptor 74 to measure the temperature of the wafer being heated. The measured temperature of the semiconductor wafer W is transmitted to the control unit 3. The controller 3 monitors whether or not the temperature of the semiconductor wafer W that is heated by light irradiation from the halogen lamp HL has reached a predetermined preheating temperature T1. The preheating temperature T1 is set to about 200 ° C. to 800 ° C., preferably about 350 ° C. to 600 ° C. (in this embodiment, 600 ° C.) at which impurities added to the semiconductor wafer W are not likely to diffuse due to heat. . Note that when the temperature of the semiconductor wafer W is increased by light irradiation from the halogen lamp HL, temperature measurement by the radiation thermometer 120 is not performed. This is because the halogen light irradiated from the halogen lamp HL enters the radiation thermometer 120 as disturbance light, and accurate temperature measurement cannot be performed.

  By the way, it is recognized that the temperature of the peripheral portion WS tends to be lower in the semiconductor wafer W being preheated than in the central portion. Possible causes of such a phenomenon include heat radiation from the peripheral portion WS of the semiconductor wafer W or heat conduction from the peripheral portion WS of the semiconductor wafer W to the susceptor 74 having a relatively low temperature.

  For this reason, the arrangement density of the halogen lamps HL in the halogen heating unit 4 is configured so that the region facing the peripheral portion WS is higher than the region facing the central portion of the semiconductor wafer W. The amount of light directed toward the peripheral portion WS is made larger than the central portion of W. Further, since the inner peripheral surface of the reflection ring 69 attached to the chamber side portion 61 is a mirror surface, a large amount of light is reflected by the inner peripheral surface of the reflection ring 69 toward the peripheral portion WS of the semiconductor wafer W. Become.

  Thus, even if the amount of halogen irradiated to the peripheral portion WS is larger than the central portion of the semiconductor wafer W, it is still difficult to eliminate the temperature drop at the peripheral portion WS of the semiconductor wafer W. This tendency becomes more prominent as the distance between the halogen lamp HL and the semiconductor wafer W held by the holding unit 7 increases.

  For this reason, in 1st Embodiment, the auxiliary irradiation part 40 which performs additional light irradiation to the peripheral part WS of the semiconductor wafer W hold | maintained at the holding | maintenance part 7 is provided. The laser unit 41 of the auxiliary irradiation unit 40 emits a visible light laser in the near infrared region having a wavelength of 800 nm to 820 nm at an output of 80 W to 500 W. Laser light emitted from the laser unit 41 and guided to the lens 43 by the optical fiber 42 enters the incident side end 45 b of the light guide rod 45 from the lens 43. Laser light is emitted from the lens 43 upward in the vertical direction, and the laser light is directly incident on the incident side end 45b.

  As shown in FIG. 11, the laser light incident perpendicularly to the incident side end 45b travels in a cylindrical shape toward the emission side end 45a inside the light guide rod 45, and enters the inside of the conical recess 45c. The light is totally reflected by the wall surface and emitted from the emission side end 45 a toward the peripheral edge WS of the semiconductor wafer W held by the holding unit 7. As described above, the center axis of the cylinder formed by the laser light traveling inside the light guide rod 45 coincides with the center axis of the light guide rod 45 and reaches the apex of the conical shape of the recess 45c. . Then, the laser light guided in a columnar shape toward the emission side end 45a through the inside of the light guide rod 45 is totally reflected by the inner wall surface of the conical recess 45c, and is emitted from the emission side end 45a. The laser beam is irradiated in an annular shape on the peripheral edge WS of the back surface of the semiconductor wafer W held by the holding unit 7. In addition, since the holding | maintenance part 7 is formed entirely with quartz, it transmits the visible light laser with a wavelength of 800 nm to 820 nm emitted from the light guide rod 45. On the other hand, the silicon semiconductor wafer W heated to some extent by the halogen heating unit 4 absorbs laser light having a wavelength of 800 nm to 820 nm. Accordingly, the laser light emitted from the auxiliary irradiation unit 40 is irradiated and absorbed on the peripheral edge WS of the semiconductor wafer W, and the temperature of the peripheral edge WS is increased.

  By the way, in the radial direction of the cylinder formed by the laser light traveling inside the light guide rod 45, the intensity of the laser light is usually not uniform. FIG. 13 is a diagram illustrating an example of an intensity distribution in a cylinder formed by laser light that travels inside the light guide rod 45. The cross-sectional intensity distribution of laser light traveling with a predetermined width is generally a Gaussian distribution. Also in this embodiment, the intensity distribution along the radial direction of the cylinder formed by the laser light guided inside the light guide rod 45 is a Gaussian distribution as shown in FIG. That is, the intensity of the laser beam that travels through the center of the cylinder is the strongest, the intensity gradually decreases continuously from the center of the cylinder toward the periphery (monotonically decreases), and the intensity of the laser beam that travels along the side of the cylinder is the weakest. Become.

  When the laser beam having such an intensity distribution is totally reflected on the inner wall surface of the conical recess 45c and irradiated to the peripheral edge WS of the back surface of the semiconductor wafer W in an annular shape, the center of the strongest cylinder The height position of the light guide rod 45 is adjusted by the slide driving unit 47 so that the laser light traveling along the edge reaches the edge WE of the semiconductor wafer W. That is, as shown in FIG. 11, the laser light traveling through the center of the cylinder has a conical apex of the recess 45 c and is totally reflected at the apex and travels toward the edge WE of the semiconductor wafer W. On the other hand, the laser light traveling along the side surface of the cylinder having the weakest intensity is totally reflected at a predetermined position on the conical side surface of the recess 45 c and reaches the inner periphery of the peripheral edge WS of the semiconductor wafer W. As a result, the illuminance distribution in the laser light irradiated in a ring shape on the peripheral edge WS of the back surface of the semiconductor wafer W becomes the strongest at the edge WE and gradually decreases from there to the inner periphery of the peripheral WS. .

  FIG. 14 is a diagram showing a correlation between the radial temperature distribution of the semiconductor wafer W and the laser light intensity distribution at the peripheral portion WS during the preheating. As shown in FIG. 14B, the temperature of the peripheral portion WS is lower in the semiconductor wafer W during the preheating than in the central region. In particular, at the peripheral edge WS of the semiconductor wafer W, the temperature gradually decreases from the inner periphery of the peripheral edge WS toward the end edge WE (monotonically decreasing), and the end edge WE has the lowest temperature.

  Laser light is irradiated to the peripheral portion WS in an annular shape from the auxiliary irradiation unit 40 to the semiconductor wafer W having such a temperature distribution with an intensity distribution as shown in FIG. That is, the laser beam having an intensity distribution of Gaussian distribution is totally reflected by the inner wall surface of the conical recess 45c and is irradiated in an annular shape onto the rear surface peripheral portion WS of the semiconductor wafer W, thereby forming a peripheral portion that is an irradiation region In WS, the laser light intensity gradually and continuously increases (monotonically increases) from the inner periphery to the edge WE of the peripheral edge WS, and becomes strongest in the edge WE.

  Therefore, the strongest laser beam is applied to the edge portion WE of the semiconductor wafer W that has the lowest temperature during preheating, and the weak laser beam is applied to the vicinity of the inner periphery of the peripheral portion WS where no significant temperature drop occurs. It will be. Then, the intensity of the laser light emitted from the inner periphery of the peripheral edge WS where the temperature gradually decreases toward the edge WE gradually increases. As a result, the laser light is irradiated from the auxiliary irradiation unit 40 to the peripheral portion WS with an intensity distribution that effectively eliminates the non-uniformity of the temperature distribution of the semiconductor wafer W during the preheating, and the peripheral portion WS is The uniformity of the in-plane temperature distribution of the semiconductor wafer W is improved by raising the temperature uniformly. The timing of starting the laser beam irradiation from the auxiliary irradiation unit 40 may be the same as the time when the halogen lamp HL is turned on, or after a predetermined time has elapsed since the halogen lamp HL was turned on. Alternatively, it may be a predetermined time before the halogen lamp HL is turned on.

  When a predetermined time elapses after the temperature of the semiconductor wafer W reaches the preheating temperature T1, the flash lamp FL irradiates the surface of the semiconductor wafer W with flash light. When the flash lamp FL irradiates flash light, the electric power is accumulated in the capacitor 93 by the power supply unit 95 in advance. Then, a pulse signal is output from the pulse generator 31 of the control unit 3 to the IGBT 96 in a state where charges are accumulated in the capacitor 93.

  The waveform of the pulse signal output from the pulse generator 31 is defined by inputting from the input unit 33 a recipe in which the pulse width time (on time) and the pulse interval time (off time) are sequentially set as parameters. Can do. When an operator inputs a recipe describing such parameters from the input unit 33 to the control unit 3, the waveform setting unit 32 of the control unit 3 sets a pulse waveform that repeats ON / OFF accordingly. Then, the pulse generator 31 outputs a pulse signal according to the pulse waveform set by the waveform setting unit 32. As a result, a pulse signal having a waveform that repeatedly turns on and off is applied to the gate of the IGBT 96, and the on / off drive of the IGBT 96 is controlled.

  Further, in synchronization with the timing when the pulse signal output from the pulse generator 31 is turned on, the control unit 3 controls the trigger circuit 97 to apply a high voltage to the trigger electrode 91. Thus, when the pulse signal input to the gate of the IGBT 96 is turned on, a current always flows between the both end electrodes in the glass tube 92, and light is emitted by excitation of the xenon atoms or molecules at that time. A pulse signal is output from the control unit 3 to the gate of the IGBT 96, and a trigger voltage is applied to the trigger electrode 91 in synchronization with the timing when the pulse signal is turned on, so that a sawtooth waveform is generated in the circuit including the flash lamp FL. Current flows. That is, the value of the current flowing in the glass tube 92 of the flash lamp FL increases when the pulse signal input to the gate of the IGBT 96 is on, and the current value decreases when the pulse signal is off. Each current waveform corresponding to each pulse is defined by a constant of the coil 94.

  When a current flows through a circuit including the flash lamp FL, the flash lamp FL emits light. The emission intensity of the flash lamp FL is substantially proportional to the current flowing through the flash lamp FL. As a result, the light emission intensity of the flash lamp FL is close to the time waveform sawtooth waveform, and the semiconductor wafer W held by the holding unit 7 is irradiated with flash light with such an intensity waveform.

  Here, when the flash lamp FL is caused to emit light without using a switching element such as the IGBT 96, the electric charge accumulated in the capacitor 93 is instantaneously consumed by one light emission. For this reason, the waveform of the light emission intensity of the flash lamp FL becomes a single pulse with a width that rises suddenly and falls rapidly about 0.1 to 10 milliseconds.

  On the other hand, as in the present embodiment, by connecting the IGBT 96 in the circuit and outputting a pulse signal to the gate thereof, the circuit is intermittently turned on / off by the IGBT 96, and the capacitor 93 switches to the flash lamp FL. The flowing current is chopper controlled. As a result, the light emission of the flash lamp FL is chopper-controlled, and the electric charge accumulated in the capacitor 93 is intermittently discharged and divided and consumed by the flash lamp FL, and the flash lamp is consumed for a very short time. FL repeats flashing. However, before the current value flowing through the flash lamp FL becomes completely “0”, the next pulse is applied to the gate of the IGBT 96 and the current value increases again. For this reason, the light emission intensity does not completely become “0” even while the flash lamp FL repeatedly blinks.

  The time waveform of the light emission intensity of the flash lamp FL can be changed as appropriate by adjusting the waveform of the pulse signal applied to the gate of the IGBT 96. The temporal waveform of the emission intensity may be determined according to the purpose of the flash heat treatment (for example, activation of implanted impurities, recovery processing of crystal defects introduced at the time of impurity implantation, etc.). However, even if the time waveform of the light emission intensity of the flash lamp FL is in any form, the total light emission time of the flash lamp FL in one heat treatment is 1 second or less. The waveform of the pulse signal applied to the gate of the IGBT 96 can be adjusted by the time of the pulse width input from the input unit 33 and the time of the pulse interval.

  By performing flash light irradiation from the flash lamp FL in this way, the surface temperature of the semiconductor wafer W is gradually raised from the preheating temperature T1 to the target processing temperature T2, and then gradually lowered. However, even if the surface temperature of the semiconductor wafer W gradually rises and then falls slowly, it is just compared to conventional flash lamp annealing, and the flash lamp FL emission time is less than 1 second. Therefore, compared with light irradiation heating using a halogen lamp or the like, the temperature rises and falls in a remarkably short time. In the first embodiment, since the auxiliary irradiation unit 40 irradiates the peripheral edge WS of the back surface of the semiconductor wafer W in an annular shape and makes the in-plane temperature distribution of the semiconductor wafer W uniform in the preheating stage, The in-plane temperature distribution on the surface of the semiconductor wafer W at the time of flash light irradiation can be made uniform.

  After the end of the flash heat treatment, the halogen lamp HL is turned off after a predetermined time has elapsed. Further, the laser beam irradiation by the auxiliary irradiation unit 40 is also stopped. Thereby, the cooling rate of the semiconductor wafer W is increased. At the same time that the halogen lamp HL is extinguished, the shutter mechanism 2 inserts the shutter plate 21 into the light shielding position between the halogen heating unit 4 and the chamber 6. Even if the halogen lamp HL is turned off, the temperature of the filament and the tube wall does not decrease immediately, but radiation heat continues to be radiated from the filament and tube wall that are hot for a while, which prevents the temperature of the semiconductor wafer W from falling. By inserting the shutter plate 21, the radiant heat radiated from the halogen lamp HL immediately after the light is turned off to the heat treatment space 65 is cut off, and the temperature drop rate of the semiconductor wafer W can be increased.

  Then, after the temperature of the semiconductor wafer W is lowered to a predetermined temperature or lower, the pair of transfer arms 11 of the transfer mechanism 10 is moved horizontally from the retracted position to the transfer operation position again and lifted, whereby the lift pins 12 are moved to the susceptor. The semiconductor wafer W protruding from the upper surface of 74 and subjected to the heat treatment is received from the susceptor 74. Subsequently, the transfer opening 66 closed by the gate valve 185 is opened, and the semiconductor wafer W placed on the lift pins 12 is unloaded by the transfer robot outside the apparatus, and the heat treatment of the semiconductor wafer W in the heat treatment apparatus 1 is performed. Is completed.

  In the first embodiment, laser light irradiation by the auxiliary irradiation unit 40 is performed in order to correct non-uniformity in the in-plane temperature distribution of the semiconductor wafer W caused by the preliminary heating by the halogen lamp HL. When the semiconductor wafer W held by the holding unit 7 is preheated from the halogen lamp HL, the temperature of the peripheral portion WS tends to be lower than the central portion of the semiconductor wafer W. By irradiating the back surface peripheral portion WS of W with a laser beam in an annular shape, the peripheral portion WS is selectively heated so that a uniform in-plane temperature distribution is obtained.

  In particular, the entire peripheral edge WS of the back surface of the semiconductor wafer W is irradiated in an annular shape, so that the entire peripheral edge WS is also irradiated at the moment when flash light is irradiated from the flash lamp FL with a total light emission time of 1 second or less. The laser beam is irradiated uniformly. For this reason, only a part of the laser beam irradiation region in the peripheral portion WS does not become locally hot during flash light irradiation, and the in-plane temperature distribution of the semiconductor wafer W can be made uniform even during flash heating. .

  Further, when the non-uniformity of the in-plane temperature distribution of the semiconductor wafer W during the preheating is viewed in more detail, the temperature tends to gradually decrease from the inner periphery of the peripheral edge WS of the semiconductor wafer W toward the edge WE. As can be seen, in the first embodiment, laser light irradiation is performed to complement this distribution. That is, the laser beam having an intensity distribution of Gaussian distribution is totally reflected by the inner wall surface of the conical recess 45c and irradiated in a ring shape on the rear surface peripheral portion WS of the semiconductor wafer W, whereby the inner periphery of the peripheral portion WS is formed. To the edge portion WE, the laser beam intensity is gradually increased. Thereby, the non-uniformity of the in-plane temperature distribution of the semiconductor wafer W during the preheating can be more effectively eliminated, and the in-plane temperature distribution of the semiconductor wafer W can be made more uniform with higher accuracy.

  Even if the center of the laser beam is simply aligned with the edge portion WE of the semiconductor wafer W, it is possible to gradually increase the laser beam intensity from the inner periphery of the peripheral portion WS toward the edge portion WE. In this case, about half of the laser light is not irradiated onto the semiconductor wafer W. Therefore, the energy efficiency of the laser light is reduced, and the laser light that has not been irradiated onto the semiconductor wafer W reaches any part of the chamber 6 and unnecessarily heats the part. According to the first embodiment, it is possible to irradiate the peripheral portion WS of the semiconductor wafer W in an annular shape without waste while complementing the nonuniform temperature distribution in the peripheral portion WS of the semiconductor wafer W. . For this reason, while suppressing the energy efficiency fall of a laser beam, the heating of the unexpected site | part in the chamber 6 can be prevented.

Second Embodiment
Next, a second embodiment of the present invention will be described. The overall configuration of the heat treatment apparatus of the second embodiment is the same as that of the first embodiment. The processing procedure for the semiconductor wafer W in the second embodiment is the same as that in the first embodiment. The second embodiment differs from the first embodiment in the configuration of the light guide rod of the auxiliary irradiation unit 40.

  FIG. 15 is a longitudinal sectional view showing the configuration of the light guide rod 145 of the second embodiment. In the figure, the same elements as those in the first embodiment are denoted by the same reference numerals. The main body portion of the light guide rod 145 of the second embodiment is a columnar optical member made of quartz, and includes an incident side end portion 45b and an emission side end portion 45a at both ends thereof. A conical recess 45c is formed at the exit side end 45a of the light guide rod 145. That is, the main body of the light guide rod 145 of the second embodiment is the same as the light guide rod 45 of the first embodiment.

  In the second embodiment, the metal film 146 is formed on the inner wall surface of the conical recess 45 c of the light guide rod 145. As such a metal film 146, a metal having high reflectivity with respect to the laser light emitted from the laser unit 41 may be used. For example, a gold (Au) film may be used.

  The laser light emitted from the laser light emitting portion 44 and incident on the incident side end portion 45b travels straight in a cylindrical shape toward the emission side end portion 45a along the longitudinal direction of the light guide rod 145, and has a conical recess 45c. Totally reflected on the inner wall surface of the. In the second embodiment, since the metal film 146 is formed on the inner wall surface of the recess 45c, the laser beam reaching the recess 45c does not leak from the inner wall surface, and all the laser beams are reliably totally reflected. The Rukoto. For this reason, all of the laser light incident on the light guide rod 145 is reflected without any waste and is irradiated onto the peripheral portion WS of the semiconductor wafer W held by the holding portion 7, thereby reducing the use efficiency of the laser light. Can be prevented.

  In FIG. 15, the metal film 146 is formed on the entire inner wall surface of the recess 45 c, but the metal film 146 is formed only in the region where the cylinder formed by the laser light incident on the light guide rod 145 reaches. Anyway.

<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 is the same as that of the first embodiment. The processing procedure for the semiconductor wafer W in the third embodiment is the same as that in the first embodiment. The third embodiment differs from the first embodiment in the configuration of the light guide rod of the auxiliary irradiation unit 40.

  FIG. 16 is a longitudinal sectional view showing the configuration of the light guide rod 245 of the third embodiment. In the figure, the same elements as those in the first embodiment are denoted by the same reference numerals. The light guide rod 245 of the third embodiment is a columnar optical member formed of quartz, and includes an incident side end 45b and an emission side end 45a at both ends thereof. A conical recess 45c is formed at the exit side end 45a of the light guide rod 245. That is, the main body of the light guide rod 245 of the third embodiment is the same as the light guide rod 45 of the first embodiment.

  In the third embodiment, a metal body 246 that fits into the conical recess 45c of the light guide rod 245 is provided. As the metal body 246, a metal having excellent heat resistance, for example, stainless steel can be used. Such metal is formed into a conical shape conforming to the recess 45c, and the side surface is mirror-polished, and the metal body 246 is fitted into the recess 45c.

  The laser light emitted from the laser light emitting portion 44 and incident on the incident side end portion 45b goes straight in a columnar shape toward the emission side end portion 45a along the longitudinal direction of the light guide rod 245, and has a conical recess 45c. Totally reflected on the inner wall surface of the. In the third embodiment, since the metal body 246 is fitted into the recess 45c, the laser light reaching the recess 45c does not leak from the inner wall surface, and all the laser light is reliably totally reflected. It becomes. For this reason, as in the second embodiment, all of the laser light incident on the light guide rod 245 is reflected by the concave portion 45c without being wasted and is applied to the peripheral portion WS of the semiconductor wafer W held by the holding portion 7. Therefore, it is possible to prevent a decrease in the utilization efficiency of the laser light.

  A metal film similar to that of the second embodiment may be formed on the side surface of the metal body 246 (that is, the contact surface with the recess 45c). Even in this case, the laser light reaching the recess 45c can be reliably totally reflected.

<Fourth embodiment>
Next, a fourth embodiment of the present invention will be described. The overall configuration of the heat treatment apparatus of the fourth embodiment is the same as that of the first embodiment. The processing procedure for the semiconductor wafer W in the fourth embodiment is the same as that in the first embodiment. The fourth embodiment is different from the first embodiment in the configuration of the light guide rod of the auxiliary irradiation unit 40.

  FIG. 17 is a diagram illustrating a light guide rod 345 according to the fourth embodiment. In the figure, the same elements as those in the first embodiment are denoted by the same reference numerals. The light guide rod 345 of the fourth embodiment is a columnar optical member made of quartz. The light guide rod 345 is provided so that the longitudinal direction of the columnar shape extends along the central axis CX of the semiconductor wafer W held by the holding unit 7.

  Both ends of the rod-shaped light guide rod 345 are an incident side end 45b and an emission side end 45a. The incident side end 45b is a flat surface as in the first embodiment, but an axicon lens 346 is attached to the emission side end 45a. The axicon lens 346 is a conical lens whose diameter decreases from the inside of the light guide rod 345 toward the semiconductor wafer W held by the holding unit 7. The central axis of the conical axicon lens 346 coincides with the central axis CX of the semiconductor wafer W. The axicon lens 346 may be processed separately from the main body of the light guide rod 345 and joined to the flat emission side end 45a, or may be molded integrally with the light guide rod 345. May be.

  The laser light emitted from the laser light emitting portion 44 and perpendicularly incident on the incident-side end portion 45 b that is a flat surface travels straight along the longitudinal direction of the light guide rod 345. The laser beam incident from the lower incident side end 45b travels in a cylindrical shape in the light guide rod 45 toward the upper emission side end 45a. The central axis of the cylinder formed by the laser light guided inside the light guide rod 345 coincides with the central axis of the light guide rod 345 (that is, the central axis CX of the semiconductor wafer W).

  As shown in FIG. 17, the laser light that has reached the axicon lens 346 at the emission side end 45 a is refracted by the wall surface of the axicon lens 346 and is applied to the peripheral edge WS of the semiconductor wafer W held by the holding unit 7. It is emitted toward. The center of the cylinder formed by the laser beam guided inside the light guide rod 345 reaches the apex of the conical axicon lens 346. The laser light refracted at the apex of the axicon lens 346 reaches the inner circumference of the peripheral edge WS of the semiconductor wafer W. On the other hand, the side surface of the cylinder formed by the laser light reaches a predetermined position (position between the apex and the bottom surface) of the side surface of the axicon lens 346. Then, the laser light refracted at the predetermined position reaches the edge portion WE of the semiconductor wafer W.

  Even in this case, the laser light emitted from the emission side end 45 a of the light guide rod 345 is irradiated in an annular shape on the peripheral edge WS of the semiconductor wafer W held by the holding unit 7. As a result, the in-plane temperature distribution of the semiconductor wafer W can be made uniform by selectively heating the peripheral edge WS of the semiconductor wafer W in which a tendency of temperature reduction is recognized during preheating.

  However, the refraction of the fourth embodiment has a smaller optical path change angle of the laser light than the reflection of the first embodiment to the third embodiment. Therefore, in order to allow the emitted laser light to reach the peripheral edge WS of the semiconductor wafer W, the semiconductor wafer W held by the light guide rod 345 and the holding part 7 as compared with the first to third embodiments. Therefore, it is necessary to ensure a long distance to the chamber 6 and to increase the size of the chamber 6.

<Fifth Embodiment>
Next, a fifth embodiment of the present invention will be described. The overall configuration of the heat treatment apparatus of the fifth embodiment is the same as that of the first embodiment. Further, the processing procedure of the semiconductor wafer W in the fifth embodiment is substantially the same as that in the first embodiment. The fifth embodiment differs from the first embodiment in the mode of laser light irradiation by the auxiliary irradiation unit 40.

  FIG. 18 is a diagram showing laser light irradiation in the fifth embodiment. In the fifth embodiment, as indicated by an arrow AR18, the rotation driving unit 46 is configured to irradiate the peripheral edge WS on the back surface of the semiconductor wafer W from the emission side end 45a of the light guide rod 45 in an annular shape. Rotates the light guide rod 45 around the central axis CX of the semiconductor wafer W as a rotation center. As a result, the annular laser beam irradiation region rotates around the central axis CX at the peripheral edge WS of the semiconductor wafer W.

  Even if the annular laser light irradiation region is rotated around the central axis CX with respect to the annular peripheral edge WS, there is no theoretical change due to the rotation, and the laser light irradiation to the peripheral edge WS of the semiconductor wafer W is performed. State is maintained. However, in the first embodiment, the center of the cylinder formed by the laser beam guided inside the light guide rod 45 is made to completely coincide with the apex of the recess 45c, and the laser beam reflected at the apex is accurately reflected on the semiconductor wafer. Since it is not easy to reach the entire periphery of the edge portion WE of W, the laser light irradiation region may be slightly shifted from the peripheral portion WS. In such a case, by rotating the light guide rod 45 around the central axis CX of the semiconductor wafer W as the center of rotation as in the fifth embodiment, uneven heating of the peripheral edge WS due to such a shift is performed. Can be eliminated. The remainder other than the point where the light guide rod 45 is rotated is the same as in the first embodiment.

<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 is the same as that of the first embodiment. Further, the processing procedure for the semiconductor wafer W in the sixth embodiment is substantially the same as that in the first embodiment. The sixth embodiment is different from the first embodiment in the mode of laser light irradiation by the auxiliary irradiation unit 40.

  FIG. 19 is a diagram showing laser light irradiation in the sixth embodiment. In the sixth embodiment, as shown by an arrow AR19, the slide drive unit 47 is irradiated with a laser beam in an annular shape from the emission side end 45a of the light guide rod 45 to the peripheral edge WS of the back surface of the semiconductor wafer W. The light guide rod 45 is reciprocated along the central axis CX of the semiconductor wafer W. As a result, as indicated by an arrow AR20, the diameter of the annular laser light irradiation region on the back surface of the semiconductor wafer W is repeatedly enlarged and reduced.

  In some cases, the width of the peripheral portion WS where the temperature is lower than that of the central region of the semiconductor wafer W during the preheating and the width of the annular laser light irradiation region by the auxiliary irradiation unit 40 may not completely match. In such a case, as in the sixth embodiment, by reciprocating the light guide rod 45 along the central axis CX of the semiconductor wafer W, the entire peripheral portion WS where the temperature is lowered is uniformly heated. can do. The remainder other than the point of reciprocating the light guide rod 45 is the same as in the first embodiment.

<Modification>
While the embodiments of the present invention have been described above, the present invention can be modified in various ways other than those described above without departing from the spirit of the present invention. For example, in the above-described embodiments, the material of the light guide rod 45 is quartz. However, the material is not limited to this, and any material having a property of transmitting laser light, such as sapphire, may be used.

  In each of the above embodiments, the laser light emitted from the laser unit 41 is guided to the lens 43 by the optical fiber 42. Instead of this, a laser unit using a collimator lens and a total reflection mirror is used. The laser light emitted from 41 may be guided to the lens 43.

  In each of the above embodiments, the IGBT 96 is incorporated in the drive circuit of the flash lamp FL and the current flowing through the flash lamp FL is chopper-controlled. Such technology can be applied. In other words, the peripheral portion WS of the semiconductor wafer W, which is relatively low in the preliminary heating stage, is irradiated with laser light in an annular shape from the auxiliary irradiating unit 40 to raise the temperature of the peripheral portion WS, and the in-plane temperature distribution is uniform. The in-plane temperature of the semiconductor wafer W at the time of the final flash light irradiation even if the flash lamp FL is irradiated with flash light in a single pulse waveform in which the current is not chopper-controlled in that state The distribution can be made uniform.

  In each of the above embodiments, the IGBT 96 is used as the switching element. However, instead of this, another transistor that can turn on and off the circuit according to the signal level input to the gate may be used. However, since a considerable amount of power is consumed for the light emission of the flash lamp FL, it is preferable to employ an IGBT or a GTO (Gate Turn Off) thyristor suitable for handling high power as the switching element.

  The setting of the waveform of the pulse signal is not limited to inputting parameters such as the pulse width one by one from the input unit 33. For example, the operator directly inputs the waveform graphically from the input unit 33. Alternatively, the waveform previously set and stored in the storage unit such as a magnetic disk may be read, or may be downloaded from the outside of the heat treatment apparatus 1.

  In each of the above embodiments, the flash heating unit 5 is provided with 30 flash lamps FL. However, the present invention is not limited to this, and the number of flash lamps FL may be an arbitrary number. it can. The flash lamp FL is not limited to a xenon flash lamp, and may be a krypton flash lamp. Further, the number of halogen lamps HL provided in the halogen heating unit 4 is not limited to 40, and may be an arbitrary number.

  In each of the above embodiments, the semiconductor wafer W is preheated by irradiation with halogen light from the halogen lamp HL. However, the preheating method is not limited to this and is placed on a hot plate. By doing so, the semiconductor wafer W may be preheated. However, the temperature of the hot plate can be individually controlled for each zone concentrically divided, and the temperature drop at the peripheral edge of the semiconductor wafer W can be eliminated by zone control. A more remarkable effect can be obtained by applying the technique according to the present invention to an apparatus for preheating the wafer W.

  The substrate to be processed by the heat treatment apparatus according to the present invention is not limited to a semiconductor wafer, and may be a glass substrate or a solar cell substrate used for a flat panel display such as a liquid crystal display device. Further, the technique according to the present invention may be applied to bonding of metal and silicon or crystallization of polysilicon.

DESCRIPTION OF SYMBOLS 1 Heat processing apparatus 2 Shutter mechanism 3 Control part 4 Halogen heating part 5 Flash heating part 6 Chamber 7 Holding part 10 Transfer mechanism 40 Auxiliary irradiation part 41 Laser unit 44 Laser beam emission part 45,145,245,345 Light guide rod 45a emission Side end portion 45b Incident side end portion 45c Recessed portion 46 Rotation drive portion 47 Slide drive portion 65 Heat treatment space 74 Susceptor 146 Metal film 246 Metal body 346 Axicon lens CX Central axis FL Flash lamp HL Halogen lamp W Semiconductor wafer WE Edge portion WS Peripheral part

Claims (9)

A heat treatment apparatus for heating a substrate by irradiating flash light onto a disk-shaped substrate,
A chamber for housing the substrate;
Holding means for holding the substrate in the chamber;
A flash lamp for irradiating the surface of the substrate held by the holding means with flash light;
Preheating means for preheating the substrate to a predetermined temperature before irradiating flash light from the flash lamp;
Auxiliary irradiation means for irradiating laser light in an annular shape to the peripheral edge of the back surface of the substrate;
A heat treatment apparatus comprising: The heat treatment apparatus according to claim 1, wherein
The auxiliary irradiation means includes
A rod-shaped light guide rod provided so as to extend along the longitudinal direction of the central axis of the substrate held by the holding means;
Laser light emitting means for making a laser beam incident from an incident side end far from the substrate held by the holding means among both ends of the light guide rod;
Including
The laser light incident from the incident side end proceeds in a cylindrical shape toward the output side end inside the light guide rod,
A conical recess having an opening diameter that increases from the inside of the light guide rod toward the substrate held by the holding means is formed at the exit side end of the light guide rod. Heat treatment equipment. The heat treatment apparatus according to claim 2,
A heat treatment apparatus, wherein a metal film is formed on a wall surface of the conical recess. The heat treatment apparatus according to claim 2,
The heat treatment apparatus, wherein the auxiliary irradiation means further includes a metal body that fits into the conical recess. In the heat processing apparatus in any one of Claims 2-4,
A heat treatment apparatus, further comprising a slide drive unit that reciprocates the light guide rod along the central axis. The heat treatment apparatus according to claim 5, wherein
The cylinder formed by the laser light guided inside the light guide rod has an intensity distribution in which the intensity continuously decreases from the center of the cylinder toward the periphery, and the center is the apex of the conical recess. Progress to reach
The heat treatment apparatus characterized in that the slide drive unit moves the light guide rod to a position where a laser beam located at the center of the cylinder reaches an edge of a substrate held by the holding means. In the heat treatment apparatus according to any one of claims 2 to 6,
A heat treatment apparatus, further comprising: a rotation driving unit that rotates the light guide rod about the central axis as a rotation center. The heat treatment apparatus according to claim 1, wherein
The auxiliary irradiation means includes
A rod-shaped light guide rod provided so as to extend along the longitudinal direction of the central axis of the substrate held by the holding means;
Laser light emitting means for making a laser beam incident from an incident side end far from the substrate held by the holding means among both ends of the light guide rod;
Including
The laser light incident from the incident side end proceeds in a cylindrical shape toward the output side end inside the light guide rod,
A conical axicon lens whose diameter decreases from the inside of the light guide rod toward the substrate held by the holding means is attached to the exit side end of the light guide rod. Heat treatment equipment. In the heat processing apparatus in any one of Claims 1-8,
The heat treatment apparatus, wherein the preheating means includes a halogen lamp that irradiates light on the back surface of the substrate held by the holding means.

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