JP2009231694A - Heat treatment apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat treatment apparatus capable of directly and accurately measuring the temperature of a substrate heated by light irradiation. <P>SOLUTION: After the temperature of a semiconductor wafer W is raised by halogen lamps HL, the lamps are turned off, and a shutter plate 21 is inserted into a light blocking position. The subsequent temperature of the semiconductor wafer W is measured by radiation thermometers 120 and 130. The radiation light from the halogen lamps HL is blocked by the shutter plate 21 immediately after the lamps are turned off, thereby the radiation thermometer 120 can directly and accurately measure the temperature of the semiconductor wafer W without being affected by disturbance light. The radiation thermometer 130 makes temperature measurement through a small hole 23 in the shutter plate 21. As the distance between the end of a quartz rod 133 and the shutter plate 21 is ≤3 mm, the radiation thermometer 130 can also accurately measure the temperature of the semiconductor wafer W with the effects of disturbance light minimized. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a heat treatment apparatus for heating a substrate by irradiating light onto a semiconductor wafer, a glass substrate or the like (hereinafter simply referred to as “substrate”).

  Conventionally, a lamp annealing apparatus using a halogen lamp has been generally used in an ion activation process of a semiconductor wafer after ion implantation. In such a lamp annealing apparatus, ion activation of a semiconductor wafer is performed by heating (annealing) the semiconductor wafer to a temperature of about 1000 ° C. to 1100 ° C., for example. In such a heat treatment apparatus, the temperature of the substrate is raised at a rate of several hundred degrees per second by using the energy of light irradiated from the halogen lamp.

  On the other hand, in recent years, as semiconductor devices have been highly integrated, it is desired to reduce the junction depth as the gate length becomes shorter. However, even when ion activation of a semiconductor wafer is performed using the above-described lamp annealing apparatus that raises the temperature of the semiconductor wafer at a speed of several hundred degrees per second, ions such as boron and phosphorus implanted in the semiconductor wafer are heated. It was found that the phenomenon of deep diffusion occurs. When such a phenomenon occurs, there is a concern that the junction depth becomes deeper than required, which hinders good device formation.

  For this reason, only the surface of the semiconductor wafer into which ions have been implanted by irradiating the surface of the semiconductor wafer with flash light using a xenon flash lamp (hereinafter simply referred to as “xenon flash lamp”). There has been proposed a technique for raising the temperature of the material in an extremely 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. It has also been found that if the flash 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 a xenon flash lamp, only the ion activation can be performed without diffusing ions deeply.

  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 irradiation from a flash lamp.

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

  Each of the apparatuses disclosed in Patent Documents 1 to 3 preheats a semiconductor wafer to a predetermined temperature and then performs flash irradiation with a flash lamp. In order to determine the timing of flash emission, the preheating temperature of the semiconductor wafer is determined. It is important to measure In the apparatus disclosed in Patent Document 3, a thermocouple is provided inside a hot plate, and when the semiconductor wafer is preheated by the hot plate, the plate temperature measured by the thermocouple is used as the wafer temperature. That is, since the temperature of the semiconductor wafer placed on the hot plate is considered to be approximately equal to the plate temperature, the wafer temperature is indirectly measured by measuring the temperature of the hot plate instead of directly measuring the temperature of the semiconductor wafer. Is measured.

  On the other hand, in the apparatuses disclosed in Patent Documents 1 and 2 that perform heat treatment by a combination of a halogen lamp and a flash lamp, a hot plate is not used for preheating, so the temperature of the semiconductor wafer must be directly measured during preheating. I must. Patent Document 1 discloses that an optical pyrometer is provided to directly measure the temperature of a semiconductor wafer.

  However, in the apparatuses disclosed in Patent Documents 1 and 2, the semiconductor wafer is heated by a halogen lamp, and in the temperature measuring mechanism of the type that measures the intensity of the radiated light from the semiconductor wafer to measure the wafer temperature, the halogen lamp This causes a problem that it becomes difficult to accurately measure the wafer temperature due to the influence of strong disturbance light from the light source.

  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 directly and accurately measuring the temperature of a substrate heated by light irradiation.

  In order to solve the above-mentioned problems, a first aspect of the present invention is a heat treatment apparatus for heating a substrate by irradiating the substrate with light, a chamber for accommodating the substrate, and the substrate in a horizontal position in the chamber. A holding means for holding; a first light irradiation means for heating the substrate held by the holding means by irradiating flash light; and a holding means provided for the lower side of the chamber. A second light irradiating unit that irradiates and heats the substrate held on the substrate, a shutter member that blocks light emitted from the second light irradiating unit, and the second light irradiating unit and the holding unit. A shutter driving means for inserting / removing the shutter member at a light shielding position therebetween, and a position that is obliquely below the substrate held by the holding means and does not overlap the substrate in plan view. A first radiation thermometer that measures the temperature of the substrate by measuring the intensity of infrared light emitted from the substrate held by the means, and the height position of the first radiation thermometer is the light shielding position When the first radiation thermometer measures the temperature of the substrate, the shutter driving means inserts the shutter member into the light shielding position.

  The invention according to claim 2 is the heat treatment apparatus according to claim 1, wherein the heat treatment apparatus is provided directly below the substrate held by the holding means and below the light shielding position, and held by the holding means. A second radiation thermometer that measures the intensity of infrared light emitted from the substrate to measure the temperature of the substrate; and the second radiation temperature when the shutter member is inserted into the light shielding position. A hole is formed in a portion immediately above the meter.

  The invention according to claim 3 is the heat treatment apparatus according to claim 2, wherein the second radiation thermometer includes a quartz rod that receives infrared light from a substrate, and is inserted in the light shielding position. The distance between the shutter member and the tip of the quartz rod is 3 mm or less.

  According to a fourth aspect of the present invention, in the heat treatment apparatus according to the second or third aspect of the present invention, the positions in the substrate surface where the temperature is measured by the first and second radiation thermometers are different from each other. It is characterized by that.

  Further, the invention of claim 5 is the heat treatment apparatus according to any one of claims 1 to 4, wherein the contact thermometer measures the temperature of the substrate in contact with the substrate held by the holding means. Is further provided.

  The invention of claim 6 is the heat treatment apparatus according to any one of claims 1 to 5, wherein the substrate is heated to a predetermined temperature or higher by light irradiation from the second light irradiation means, and When the shutter member is inserted into the light shielding position and the temperature of the substrate measured by the first radiation thermometer is lowered to the predetermined temperature, the first light irradiation unit is controlled to irradiate the substrate with flash light. And further comprising a control means.

  According to a seventh aspect of the present invention, in the heat treatment apparatus according to the sixth aspect of the invention, the first light irradiation means includes a flash lamp, and the second light irradiation means includes a halogen lamp.

  According to the present invention, when the first radiation thermometer for measuring the temperature of the substrate by measuring the intensity of the infrared light emitted from the substrate held by the holding means measures the temperature of the substrate, the shutter member is Since it is inserted at the light shielding position between the second light irradiation means and the holding means, the influence of the disturbance light emitted from the second light irradiation means can be eliminated and the substrate temperature can be measured directly and accurately.

  In particular, according to the invention of claim 3, since the distance between the shutter member inserted at the light shielding position and the tip of the quartz rod of the second radiation thermometer is 3 mm or less, the second radiation thermometer also emits the second light. The temperature of the substrate can be directly and accurately measured while suppressing the influence of disturbance light emitted from the means.

  In particular, according to the invention of claim 4, since the positions in the substrate surface where the temperatures are measured by the first radiation thermometer and the second radiation thermometer are different from each other, the in-plane temperature distribution of the substrate can be measured.

  In particular, according to the invention of claim 5, since the contact-type thermometer for measuring the temperature of the substrate in contact with the substrate held by the holding means is provided, it is affected by the radiation light from the second light irradiation means. The substrate temperature can be directly measured without any problems.

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

  FIG. 1 is a side sectional view showing a configuration of a heat treatment apparatus 1 according to the present invention. The heat treatment apparatus 1 of the present embodiment is a flash lamp annealing apparatus that heats a semiconductor wafer W by irradiating flash light (flash light) onto a disk-shaped semiconductor wafer W having a diameter of 300 mm as a substrate.

  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 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.

  FIG. 2 is an enlarged partial cross-sectional view of the side portion of the chamber 6. 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.

  As shown in FIG. 2, the inner peripheral surfaces of the reflection rings 68 and 69 mounted on the upper and lower sides with the concave portion 62 interposed therebetween are tapered surfaces. The diameter of the tapered surface of the upper reflection ring 68 increases toward the lower side. Conversely, the tapered surface of the lower reflecting ring 69 increases in diameter toward the upper side. On the other hand, as shown in FIG. 1, the holding portion 7 that holds the semiconductor wafer W is provided at the height position of the recess 62. Accordingly, both the upper reflection ring 68 and the lower reflection ring 69 are formed with tapered surfaces extending from the quartz window (upper chamber window 63 and lower chamber window 64) side toward the holding portion 7 side. Become.

  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 (that is, taper 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, the chamber 6 is configured to supply a processing gas (nitrogen gas (N ₂ ) in the present embodiment) from the upper part of the heat treatment space 65 and exhaust from the lower part. As shown in FIG. 2, in the upper part of the chamber 6, the reflection ring 68 attached to the chamber side portion 61 and the upper chamber window 63 are not in close contact with each other, and a gap is formed between them. Since the upper chamber window 63 has a disc shape and the reflection ring 68 has an annular shape, the gap formed between the upper chamber window 63 and the upper end surface of the reflection ring 68 also becomes an annular slit 81. Further, a buffer space 82 is formed between the chamber side portion 61 and the reflection ring 68. The buffer space 82 is also formed in an annular shape. The buffer space 82 communicates with the slit 81.

  A gas pipe 83 is connected to the buffer space 82 in communication. The base end of the gas pipe 83 is connected to a nitrogen gas supply source 85 (FIG. 1). A valve 84 is inserted in the middle of the path of the gas pipe 83. When the valve 84 is opened, nitrogen gas is supplied from the nitrogen gas supply source 85 to the buffer space 82. Nitrogen gas flowing into the buffer space 82 passes through the slit 81 and is supplied to the heat treatment space 65 in the chamber 6.

  FIG. 3 is a plan view showing gas supply to the heat treatment space 65. In the gas passage route from the buffer space 82 to the slit 81, the cross-sectional area of the surface perpendicular to the gas traveling direction is larger in the buffer space 82 than in the slit 81. In other words, the buffer space 82 has a smaller fluid resistance than the slit 81. For this reason, as shown in FIG. 3, although a part of the nitrogen gas flowing into the buffer space 82 from the gas pipe 83 immediately flows into the slit 81, most of the nitrogen gas flows so as to expand in the buffer space 82 having a smaller resistance. Then, nitrogen gas filled in the buffer space 82 is supplied to the heat treatment space 65 through the slit 81. Therefore, nitrogen gas is uniformly supplied over the entire circumference of the annular slit 81.

  On the other hand, at the bottom of the chamber 6 as well as the top, the reflection ring 69 and the lower chamber window 64 are not in close contact with each other, and a gap is formed between them. Since the lower chamber window 64 has a disc shape and the reflection ring 69 has an annular shape, the gap formed between the lower chamber window 64 and the lower end surface of the reflection ring 69 also becomes an annular slit 86. . In addition, an annular buffer space 87 formed in the chamber side portion 61 communicates with the slit 86. A gas pipe 88 is connected to the buffer space 87 in communication. A proximal end portion of the gas pipe 88 is connected to the exhaust portion 90. A valve 89 is inserted midway along the gas pipe 88. When the valve 89 is opened, the gas in the heat treatment space 65 is discharged from the slit 86 through the buffer space 87 to the gas pipe 88.

  Also in the gas passage route from the slit 86 to the buffer space 87, the buffer space 87 is larger in the cross-sectional area of the surface perpendicular to the gas traveling direction than the slit 86. In other words, the buffer space 87 has a smaller fluid resistance than the slit 86. For this reason, the gas is uniformly exhausted over the entire circumference of the annular slit 86. For convenience of illustration, the positions of the gas pipes 83 and 88 are different between FIGS. 1 and 2, but the gas pipes 83 and 88 may be connected to arbitrary positions of the annular buffer spaces 82 and 87. Both gas pipes 83 and 88 may be connected as shown in FIG. 1 or as shown in FIG. Further, the gas pipes 83 and 88 connected to the buffer spaces 82 and 87 are not limited to one, and a plurality of gas pipes may be used. If a plurality of gas pipes 83, 88 are evenly connected to the buffer spaces 82, 87, more uniform air supply / exhaust can be performed from the annular slits 81, 86.

  As described above, the heat treatment apparatus 1 is provided with a supply / exhaust mechanism substantially symmetrically with respect to the semiconductor wafer W held in the chamber 6. That is, the heat treatment space in the chamber 6 from the slit 81 which is a gap formed annularly between the upper chamber window 63 and the inner wall upper end of the chamber 6 by the air supply mechanism having the valve 84, the gas pipe 83 and the buffer space 82. Process gas (nitrogen gas) is supplied to 65. At the same time, the gas in the chamber 6 from the slit 86 which is a gap formed between the lower chamber window 64 and the lower end of the inner wall of the chamber 6 by the exhaust mechanism having the valve 89, the gas pipe 88 and the buffer space 87. Exhaust. The nitrogen gas supply source 85 and the exhaust unit 90 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.

  FIG. 4 is a plan view of the chamber 6 as seen from the holding position of the semiconductor wafer W. FIG. The holding unit 7 includes a susceptor 70 and a soaking ring 75. The susceptor 70 is made of quartz, and is configured such that a plurality of claw portions 72 (four in this embodiment) are erected on an annular ring portion 71. The susceptor 70 is attached to the chamber 6 by placing the ring portion 71 on the bottom surface of the recess 62.

  The soaking ring 75 is a ring-shaped member made of silicon carbide (SiC), and is supported by a support pin provided on the claw portion 72 of the susceptor 70. A plurality of claws (not shown) project from the inner circumference of the heat equalizing ring 75, and the peripheral edge portion of the semiconductor wafer W is supported by the plurality of claws to hold the semiconductor wafer W in a horizontal posture. Instead of the plurality of claws, a ridge may be provided along the inner periphery of the soaking ring 75 so that the semiconductor wafer W is held.

  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 the inside of the soaking ring 75, and the upper end of the lift pin 12 is on the upper side of the soaking ring 75. Stick out. On the other hand, when the elevating mechanism 14 lowers the pair of transfer arms 11 at the transfer operation position and the horizontal movement mechanism 13 moves the pair of transfer arms 11 to open, each transfer arm 11 moves to the retracted position. To do.

  The retracted position of the pair of transfer arms 11 is directly above the ring portion 71 of the susceptor 70. Since the ring portion 71 is placed on the bottom surface of the recess 62, the retracted position of the transfer arm 11 is inside the recess 62.

  As shown in FIG. 4, an exhaust pipe 93 is connected to a portion of the chamber side portion 61 where the drive unit (the horizontal movement mechanism 13 and the lifting mechanism 14) of the transfer mechanism 10 is provided. The exhaust pipe 93 is connected to the exhaust unit 90. A valve 94 is inserted in the course of the exhaust pipe 93. By opening the valve 94, the gas in the chamber 6 is exhausted through the periphery of the drive unit of the transfer mechanism 10. Further, an exhaust pipe 91 that exhausts the gas in the heat treatment space 65 is also connected to the tip of the transfer opening 66. The exhaust pipe 91 is connected to the exhaust unit 90 via a valve 92. By opening the valve 92, the gas in the chamber 6 is exhausted through the transfer opening 66. In the present embodiment, the exhaust units 90 of the three exhaust mechanisms are common, but they may be separate.

  The flash heating unit 5 provided above the chamber 6 is provided inside the housing 51 so as to cover a light source composed of a plurality of (30 in this embodiment) xenon flash lamps FL and the light source. And the reflector 52 formed. 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.

  The xenon flash lamp FL has a rod-shaped glass tube (discharge tube) in which xenon gas is sealed and an anode and a cathode connected to a capacitor at both ends thereof, and an outer peripheral surface of the glass tube. And a triggered electrode. Since xenon gas is an electrical insulator, electricity does not flow into the glass tube under normal conditions even if electric charges are accumulated in the capacitor. However, if the insulation is broken by applying a high voltage to the trigger electrode, the electricity stored in the capacitor instantaneously flows into the glass tube, and the xenon gas is heated by Joule heat at that time, and light is emitted. . In such a xenon flash lamp FL, the electrostatic energy previously stored in the capacitor is converted into an extremely short light pulse of 0.1 to 10 milliseconds, so that the continuous lighting such as the halogen lamp HL is possible. It has the characteristic that it can irradiate extremely strong light compared with a light source.

  In addition, the reflector 52 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 flash 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. 7 is a plan view showing the arrangement of the 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. 7, 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 stage and the lower stage. 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, 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 the lower chamber window 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.

  As shown in FIG. 4, a radiation thermometer (first radiation thermometer) 120 and a contact thermometer 140 for measuring the temperature of the semiconductor wafer W are provided inside the chamber 6. As shown in FIG. 1, the halogen heating unit 4 is also provided with a radiation thermometer (second radiation thermometer) 130 for measuring the temperature of the semiconductor wafer W. FIG. 8 is a diagram schematically showing a temperature measurement mechanism of the semiconductor wafer W in the heat treatment apparatus 1.

  The radiation thermometer 120 measures the intensity (energy amount) of the radiated light (infrared light) radiated from the back surface of the semiconductor wafer W held by the soaking ring 75 of the holding unit 7 to measure the temperature of the semiconductor wafer W. Measure. Specifically, the radiation thermometer 120 includes a condensing lens and an infrared sensor (not shown), and receives infrared light emitted from the back surface of the semiconductor wafer W held by the soaking ring 75 to electrically Output as a signal. The electrical signal output from the radiation thermometer 120 is converted into a signal indicating temperature by the detector 121 and transmitted to the control unit 3.

  The radiation thermometer 120 is provided obliquely below the semiconductor wafer W held by the holding unit 7 and at a position that does not overlap the semiconductor wafer W in plan view. Specifically, the radiation thermometer 120 is installed in the recess 62 below the semiconductor wafer W held by the holding unit 7. Therefore, the height position of the radiation thermometer 120 is between the light shielding position of the shutter plate 21 and the holding unit 7. A part or all of the radiation thermometer 120 may be embedded in the chamber side portion 61 that forms the recess 62.

  Moreover, the radiation thermometer 120 is installed so that the optical axis 122 of the condensing lens which condenses infrared rays may incline by a predetermined angle with respect to a horizontal surface. The inclination angle of the optical axis 122 of the condenser lens with respect to the horizontal plane is greater than 0 ° and less than 90 °. In order to collect infrared rays from the semiconductor wafer W, it is preferable that the inclination angle of the optical axis 122 with respect to the horizontal plane is large. However, the inclination angle is set so that the radiation thermometer 120 does not overlap the semiconductor wafer W in plan view. In order to increase the size, the size in the height direction of the chamber 6 must be significantly increased. For this reason, in this embodiment, the radiation thermometer 120 is installed so that the inclination angle of the optical axis 122 of the condenser lens with respect to the horizontal plane is about 14 °.

  The radiation thermometer 120 receives infrared light emitted from the region A intersecting the optical axis 122 of the condenser lens in the surface of the semiconductor wafer W held by the holding unit 7 and measures temperature. Therefore, strictly speaking, the radiation thermometer 120 measures the temperature of the region A of the semiconductor wafer W held by the holding unit 7.

  The radiation thermometer 130 also measures the temperature of the semiconductor wafer W by measuring the intensity of the radiated light (infrared light) emitted from the back surface of the semiconductor wafer W held by the soaking ring 75 of the holding unit 7. The radiation thermometer 130 includes a quartz rod 133 for receiving light and an infrared sensor (not shown). The infrared light emitted from the back surface of the semiconductor wafer W held by the soaking ring 75 is transmitted by the quartz rod 133. Light is received and output as an electrical signal. The electrical signal output from the radiation thermometer 130 is converted into a signal indicating temperature by the detector 131 and transmitted to the control unit 3.

  The radiation thermometer 130 is provided directly below the semiconductor wafer W held by the holding unit 7 and below the light shielding position of the shutter plate 21. Specifically, the radiation thermometer 130 is installed in the halogen heating unit 4 below the lower chamber window 64. Although the radiation thermometer 130 can receive infrared rays from directly below the semiconductor wafer W held by the holding unit 7, the measurement distance from the semiconductor wafer W is longer than that of the radiation thermometer 120.

  The quartz rod 133 of the radiation thermometer 130 is a quartz rod-shaped member. The radiation thermometer 130 is provided so that the optical axis 132 of the quartz rod 133 is along the vertical direction. The radiation thermometer 130 receives infrared light emitted from the region B intersecting the optical axis 132 of the quartz rod 133 in the plane of the semiconductor wafer W held by the holding unit 7 and measures temperature. Therefore, strictly speaking, the radiation thermometer 130 measures the temperature of the region B of the semiconductor wafer W held by the holding unit 7.

  Further, a small hole 23 is formed in the shutter plate 21 so as to penetrate in the vertical direction. A small hole 23 is formed in a portion immediately above the quartz rod 133 when the shutter plate 21 is inserted into the light shielding position. Therefore, even if the shutter plate 21 is inserted at the light shielding position and the lower chamber window 64 and the plurality of halogen lamps HL are blocked, the emitted light from the semiconductor wafer W is received by the quartz rod 133 through the small holes 23. Therefore, the temperature measurement of the semiconductor wafer W by the radiation thermometer 130 is possible. When the shutter plate 21 is inserted at the light shielding position, the distance between the upper end of the quartz rod 133 and the shutter plate 21 is 3 mm or less.

  On the other hand, the contact-type thermometer 140 incorporates a thermocouple (not shown) and measures the temperature of the semiconductor wafer W by contacting the back surface of the semiconductor wafer W held by the soaking ring 75 of the holding unit 7. To do. The voltage of the electromotive force generated in the thermocouple when the tip of the contact-type thermometer 140 contacts the back surface of the semiconductor wafer W held by the soaking ring 75 is converted into a signal indicating temperature by the detector 141, and the control unit. 3 is transmitted. The contact thermometer 140 may be provided so as to protrude from the chamber side portion 61.

  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 has a magnetic disk.

  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 of the semiconductor wafer W in the heat treatment apparatus 1 will be briefly described. Here, the semiconductor wafer W to be processed is a semiconductor substrate to which an impurity (ion) is added by an ion implantation method, and the activation of the added impurity is performed by a flash heating process by the heat treatment apparatus 1. FIG. 9 is a diagram showing a temperature profile of the semiconductor wafer W during the heat treatment. FIG. 10 is a flowchart showing a processing procedure for the semiconductor wafer W in the heat treatment apparatus 1. The processing procedure of the semiconductor wafer W shown below is executed 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, 92, and 94 are opened, and supply / exhaust into the chamber 6 is started (step S1). When the valve 84 is opened, nitrogen gas is uniformly supplied to the heat treatment space 65 from the entire circumference of the annular slit 81 formed between the upper chamber window 63 and the upper end of the inner wall of the chamber 6. When the valve 89 is opened, the gas in the chamber 6 is uniformly exhausted from the entire circumference of the annular slit 86 formed between the lower chamber window 64 and the lower end of the inner wall of the chamber 6. Thereby, the nitrogen gas supplied from the uppermost part of the heat treatment space 65 in the chamber 6 flows downward and is exhausted from the lowermost part of the heat treatment space 65.

  Further, when the valves 92 and 94 are opened, the gas in the chamber 6 is exhausted through the transport opening 66 and the periphery of the drive unit of the transfer mechanism 10. Thereby, the nitrogen gas supplied from the uppermost part of the heat treatment space 65 in the chamber 6 flows around the transfer opening 66 and the drive unit of the transfer mechanism 10 and is exhausted. 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 processing steps of FIG. 10.

  Subsequently, the gate valve 185 is opened to open the transfer opening 66, and the semiconductor wafer W after the 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 ( Step S2). 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 pin 12 protrudes upward through the inside of the heat equalizing ring 75 and moves from the transfer robot. A semiconductor wafer W is received.

  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 heat equalizing ring 75 of the holding unit 7 and held in a horizontal posture. The pair of transfer arms 11 lowered to the lower side of the heat equalizing ring 75 is retracted to the retracted position, that is, inside the recess 62 by the horizontal moving mechanism 13. Even after the semiconductor wafer W is held by the holding unit 7, the nitrogen gas supplied from the uppermost part of the heat treatment space 65 passes through the side of the semiconductor wafer W (the gap between the claw portions 72 of the holding unit 7). It flows to.

  After the semiconductor wafer W is held by the soaking ring 75 of the holding unit 7, the 40 halogen lamps HL are turned on all at once and preheating (assist heating) is started (step S3). The halogen light emitted from the halogen lamp HL passes through the lower chamber window 64 made of quartz and is irradiated from the back surface of the semiconductor wafer W. By receiving light from the halogen lamp HL, the semiconductor wafer W is preheated and the temperature rises. The radiation thermometer 120 is provided at a position that does not overlap with the semiconductor wafer W held by the holding unit 7 in plan view, so that the light irradiated to the semiconductor wafer W from the halogen lamp HL is emitted by the radiation thermometer 120. There is no blocking.

  In the preheating stage, the temperature of the peripheral portion of the semiconductor wafer W, which is more likely to radiate heat, tends to be lower than that of the central portion. The in-plane temperature distribution is kept uniform. In addition, the arrangement density of the halogen lamps HL in the halogen heating unit 4 is higher in the region facing the peripheral portion than in the region facing the central portion of the semiconductor wafer W, so that the semiconductor wafer W is likely to generate heat. The amount of light irradiated on the peripheral edge of the semiconductor wafer increases, and the in-plane temperature distribution of the semiconductor wafer W in the preheating stage can be made more uniform.

  Further, the reflecting ring 69 attached to the chamber side portion 61 is formed with a tapered surface that expands toward the holding portion 7, and the tapered surface is made into a mirror surface by nickel plating. As a result, the amount of light reflected toward the peripheral edge of the semiconductor wafer W increases, and the in-plane temperature distribution of the semiconductor wafer W in the preheating stage can be made more uniform.

  When heating with the halogen lamp HL, the temperature of the semiconductor wafer W is measured by the contact thermometer 140. That is, a contact thermometer 140 incorporating a thermocouple contacts the back surface of the semiconductor wafer W held by the holding unit 7 and measures the temperature of the wafer being heated. The temperature of the semiconductor wafer W measured by the contact thermometer 140 is transmitted from the detector 141 to the control unit 3. The control unit 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 (step S4). 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 thermometers 120 and 130 is not performed. This is because the halogen light irradiated from the halogen lamp HL enters the radiation thermometers 120 and 130 as disturbance light, and accurate temperature measurement cannot be performed.

  In the present embodiment, the preheating temperature T1 is about 830 ° C. After the contact thermometer 140 detects that the temperature of the semiconductor wafer W has reached the preheating temperature T1, the output of the halogen lamp HL is adjusted to maintain the semiconductor wafer W at the preheating temperature T1, Time preheating is performed (step S5). The preheating time at the temperature T1 is about several seconds.

  After the preheating for a predetermined time is completed, the 40 halogen lamps HL are turned off all at once, and the temperature lowering of the semiconductor wafer W is started (step S6). 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 (step S7). 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.

  Moreover, temperature measurement by the radiation thermometers 120 and 130 is started when the shutter plate 21 is inserted at the light shielding position. That is, the radiation thermometers 120 and 130 measure the intensity of the infrared light emitted from the back surface of the semiconductor wafer W held by the holding unit 7 to measure the temperature of the semiconductor wafer W during the temperature drop. The temperatures of the semiconductor wafers W measured by the radiation thermometers 120 and 130 are transmitted from the detectors 121 and 131 to the control unit 3, respectively.

  The radiation thermometer 130 is provided below the light shielding position, and the shutter plate 21 inserted in the light shielding position blocks the semiconductor wafer W and the radiation thermometer 130, but the shutter plate 21 has a small hole 23. When the shutter plate 21 is inserted at the light shielding position, the small hole 23 is located at a position directly above the quartz rod 133. For this reason, even if the shutter plate 21 is inserted at the light shielding position and the semiconductor wafer W and the radiation thermometer 130 are blocked, the infrared light from the semiconductor wafer W is received by the quartz rod 133 through the small hole 23. Therefore, the temperature measurement of the semiconductor wafer W by the radiation thermometer 130 is possible.

  In addition, although some radiated light continues to be emitted from the high-temperature halogen lamp HL immediately after the lamp is turned off, the shutter plate 21 is inserted into the light shielding position between the halogen heating unit 4 and the chamber 6 to thereby store the inside of the chamber 6. Radiation to the heat treatment space 65 is shielded from light. Therefore, the radiation thermometer 120 installed at a height position between the light shielding position and the holding unit 7 accurately measures the temperature of the semiconductor wafer W held by the holding unit 7 without being affected by disturbance light. can do.

  On the other hand, the radiation thermometer 130 is installed in the halogen heating section 4 below the light shielding position. When the shutter plate 21 is inserted into the light shielding position, the tip of the quartz rod 133 and the shutter plate 21 The distance is 3 mm or less. For this reason, the radiation light from the halogen lamp HL immediately after extinguishing is prevented from entering the tip of the quartz rod 133 to the minimum, and the radiation thermometer 130 is held in the holding unit 7 by eliminating the influence of disturbance light as much as possible. The temperature of the semiconductor wafer W thus obtained can be accurately measured.

  The controller 3 monitors whether or not the temperature of the semiconductor wafer W measured by the radiation thermometers 120 and 130 has dropped to a predetermined temperature T2 (step S8). Then, when the radiation thermometers 120 and 130 detect that the temperature of the semiconductor wafer W has decreased to the predetermined temperature T2, flash light is irradiated from the flash lamp FL of the flash heating unit 5 toward the semiconductor wafer W ( Step S9). The temperature T2 of flash emission in this embodiment is 800 ° C. A part of the flash light emitted from the flash lamp FL directly goes to the holding unit 7 in the heat treatment space 65, and another part is once reflected by the reflector 52 and then goes into the heat treatment space 65. Flash heating of the semiconductor wafer W is performed by irradiation with flash light. Since the flash heating is performed by flash irradiation from the flash lamp FL, the surface temperature of the semiconductor wafer W can be increased in a short time.

  That is, the flash light irradiated from the flash lamp FL of the flash heating unit 5 has an irradiation time of about 0.1 to 10 milliseconds, in which the electrostatic energy stored in advance is converted into an extremely short light pulse. It is a very short and strong flash. The surface temperature of the semiconductor wafer W flash-heated by flash irradiation from the flash lamp FL instantaneously rises to a processing temperature T3 of about 1000 ° C. to 1100 ° C., and the impurities added to the semiconductor wafer W are activated. After being done, the surface temperature drops rapidly. As described above, in the heat treatment apparatus 1, the surface temperature of the semiconductor wafer W can be raised and lowered in a very short time, so that the impurities are activated while suppressing diffusion of impurities added to the semiconductor wafer W due to heat. Can do. Since the time required for activation of the added impurity is extremely short compared to the time required for thermal diffusion, activation is possible even for a short time when no diffusion of about 0.1 millisecond to 10 millisecond occurs. Is completed.

  The heat treatment apparatus 1 of the present embodiment performs flash heating by irradiating flash light from a flash lamp FL onto a semiconductor wafer W having a temperature T2 (800 ° C.) heated by a halogen lamp HL. For this reason, the surface temperature of the semiconductor wafer W can be quickly raised to the processing temperature T3 (1000 ° C. to 1100 ° C.). In addition, since the temperature rise range by flash heating from the flash emission temperature T2 to the processing temperature T3 is relatively small (200 ° C. to 300 ° C.), the energy of the flash light emitted from the flash lamp FL can be relatively small As a result, the thermal shock applied to the semiconductor wafer W during flash heating can be mitigated.

  Even after the flash heating, the temperature measurement of the semiconductor wafer W by the radiation thermometers 120 and 130 is continued. 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 again moved horizontally from the retracted position to the transfer operation position, so that the lift pins 12 are leveled. The semiconductor wafer W protruding from the inside of the heat ring 75 and subjected to the heat treatment is received from the holding unit 7. 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 (step S10), and the semiconductor wafer in the heat treatment apparatus 1 is transferred. The W flash heat treatment is completed.

  The heat treatment apparatus 1 of the present embodiment measures the temperature of the semiconductor wafer W after turning off the halogen lamp HL with the radiation thermometers 120 and 130. When the radiation thermometer 120 installed at a height position between the light shielding position of the shutter plate 21 and the holding unit 7 measures the intensity of infrared light emitted from the semiconductor wafer W to measure the wafer temperature. The slide drive mechanism 22 inserts the shutter plate 21 into the light shielding position. For this reason, the radiation thermometer 120 can directly and accurately measure the temperature of the semiconductor wafer W without being affected by the disturbance light emitted from the halogen lamp HL immediately after being turned off.

  The radiation thermometer 130 provided in the halogen heating unit 4 receives the infrared light emitted from the semiconductor wafer W through the small hole 23 of the shutter plate 21 inserted in the light shielding position, and measures the wafer temperature. To do. Since the distance between the tip of the quartz rod 133 of the radiation thermometer 130 and the shutter plate 21 is 3 mm or less, the radiation thermometer 130 minimizes the influence of disturbance light radiated from the halogen lamp HL immediately after extinguishing. Meanwhile, the temperature of the semiconductor wafer W can be directly and accurately measured.

  By accurately measuring the temperature of the semiconductor wafer W after the halogen lamp HL is extinguished by the radiation thermometers 120 and 130, the flash emission can be performed with good reproducibility when the temperature of the semiconductor wafer W is lowered to the temperature T2. The surface temperature of the semiconductor wafer W during heating can be stably raised to the processing temperature T3.

  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 embodiment, the temperature of the semiconductor wafer W after the halogen lamp HL is turned off is measured by the radiation thermometers 120 and 130. In addition to this, the measurement by the contact thermometer 140 is performed. Anyway. However, the contact-type thermometer 140 that measures the temperature with a thermocouple is less responsive than the radiation thermometers 120 and 130, and the measurement result of the radiation thermometers 120 and 130 is used to determine the timing of flash emission. Is preferred. On the other hand, since the contact-type thermometer 140 is not affected by ambient light at all, the temperature of the semiconductor wafer W can be measured more accurately than the radiation thermometers 120 and 130 when the halogen lamp HL is turned on. .

  In the above-described embodiment, the two radiation thermometers 120 and 130 are provided at different positions, but only one of them may be provided as long as the temperature of the semiconductor wafer W can be accurately measured. As for the radiation thermometer 120, the distance from the semiconductor wafer W to be measured is short, and the influence of disturbance light from the halogen lamp HL can be almost completely eliminated by inserting the shutter plate 21 in the light shielding position. There are advantages. Further, it is not necessary to provide a small hole in the shutter plate 21. On the other hand, the radiation thermometer 130 has an advantage that infrared light can be received from a direction perpendicular to the main surface of the semiconductor wafer W to be measured. However, if the two radiation thermometers 120 and 130 are provided as in the above-described embodiment and both measure the temperature at different positions (region A and region B) in the surface of the semiconductor wafer W, the semiconductor It is also possible to measure the in-plane temperature distribution of the wafer W.

  Further, the preheating temperature T1, the temperature T2 at which flash emission is performed, and the processing temperature T3 are not limited to the above example, and can be set to arbitrary temperatures. For example, the preheating temperature T1 may be about 950 ° C.

In the above embodiment, the processing gas supplied to the heat treatment space 65 is nitrogen gas (N ₂ ). However, the present invention is not limited to this. For example, helium (He) gas, argon (Ar) gas, etc. Inert gas, or oxygen (0 ₂ ) gas or clean air may be used. However, since the semiconductor wafer W heated in the heat treatment space 65 is heated to a high temperature of several hundred to 1000 ° C., an inert gas such as nitrogen, helium, or argon is preferable as the processing gas. In terms of surface, inexpensive nitrogen gas is preferable.

  In the above embodiment, the temperature of the semiconductor wafer W is increased by the halogen lamp HL to the preheating temperature T1 higher than the flash emission temperature T2, and then the halogen lamp HL is turned off and the semiconductor wafer W reaches the temperature T2. The flash heating is performed when the temperature is lowered. However, the flash lamp FL may be flashed immediately when the temperature of the semiconductor wafer W is increased to the temperature T2 by the halogen lamp HL. In this case, simultaneously with the flash emission, the halogen lamp HL is turned off and the shutter plate 21 is inserted into the light shielding position, and the temperature of the semiconductor wafer W being cooled is measured by the radiation thermometers 120 and 130.

  In the above embodiment, 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 can be any number. . 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 the above embodiment, the semiconductor wafer is irradiated with light to perform the ion activation process. However, the substrate to be processed by the heat treatment apparatus according to the present invention is not limited to the semiconductor wafer. . For example, the glass substrate on which various silicon films such as a silicon nitride film and a polycrystalline silicon film are formed may be processed by the heat treatment apparatus according to the present invention. As an example, an amorphous silicon film made amorphous by ion implantation of silicon into a polycrystalline silicon film formed on a glass substrate by a CVD method is formed, and a silicon oxide film serving as an antireflection film is further formed thereon. Form. In this state, the entire surface of the amorphous silicon film is irradiated with light by the heat treatment apparatus according to the present invention, so that a polycrystalline silicon film obtained by polycrystallizing the amorphous silicon film can be formed.

  Further, a heat treatment according to the present invention is applied to a TFT substrate having a structure in which a base silicon oxide film and a polysilicon film obtained by crystallizing amorphous silicon are formed on a glass substrate, and the polysilicon film is doped with impurities such as phosphorus and boron. It is also possible to activate the impurities implanted in the doping process by irradiating light with an apparatus.

It is a sectional side view which shows the structure of the heat processing apparatus which concerns on this invention. It is the fragmentary sectional view which expanded the side part of the chamber. It is a top view which shows the gas supply to heat processing space. It is the top view of the chamber seen from the holding position of the semiconductor wafer. It is a top view of a transfer mechanism. It is a side view of a transfer mechanism. It is a top view which shows arrangement | positioning of a some halogen lamp. It is a figure which shows typically the temperature measurement mechanism of the semiconductor wafer in a heat processing apparatus. It is a figure which shows the temperature profile of the semiconductor wafer at the time of heat processing. It is a flowchart which shows the process sequence of the semiconductor wafer in the heat processing apparatus of FIG.

Explanation of symbols

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 21 Shutter plate 22 Slide drive mechanism 23 Small hole 61 Chamber side part 62 Recessed part 63 Upper chamber window 64 Lower chamber Window 65 Heat treatment space 70 Susceptor 75 Soaking ring 120, 130 Radiation thermometer 133 Quartz rod 140 Contact thermometer FL Flash lamp HL Halogen lamp W Semiconductor wafer

Claims (7)

A heat treatment apparatus for heating a substrate by irradiating the substrate with light,
A chamber for housing the substrate;
Holding means for holding the substrate in a horizontal position in the chamber;
A first light irradiating means provided on the upper side of the chamber and irradiating the substrate held by the holding means with flash light;
A second light irradiating means provided on the lower side of the chamber and irradiating and heating the substrate held by the holding means;
A shutter member for shielding light emitted from the second light irradiation means;
Shutter driving means for inserting and removing the shutter member at a light shielding position between the second light irradiation means and the holding means;
The substrate is measured by measuring the intensity of infrared light that is provided obliquely below the substrate held by the holding means and does not overlap with the substrate in plan view and emitted from the substrate held by the holding means. A first radiation thermometer for measuring the temperature of
With
The height position of the first radiation thermometer is between the light shielding position and the holding means,
When the first radiation thermometer measures the temperature of the substrate, the shutter driving means inserts the shutter member into the light shielding position. The heat treatment apparatus according to claim 1, wherein
The temperature of the substrate is measured by measuring the intensity of infrared light that is provided directly below the substrate held by the holding unit and below the light shielding position and emitted from the substrate held by the holding unit. A second radiation thermometer
A heat treatment apparatus, wherein a hole is formed in the shutter member at a position directly above the second radiation thermometer when inserted into the light shielding position. The heat treatment apparatus according to claim 2,
The second radiation thermometer includes a quartz rod that receives infrared light from the substrate,
A heat treatment apparatus, wherein a distance between the shutter member inserted at the light shielding position and a tip of the quartz rod is 3 mm or less. In the heat treatment apparatus according to claim 2 or claim 3,
The heat treatment apparatus characterized in that positions on the substrate surface where temperatures are measured by the first radiation thermometer and the second radiation thermometer are different from each other. In the heat processing apparatus in any one of Claims 1-4,
A heat treatment apparatus, further comprising a contact thermometer that contacts the substrate held by the holding means and measures the temperature of the substrate. In the heat processing apparatus in any one of Claims 1-5,
After the substrate is heated to a predetermined temperature or higher by light irradiation from the second light irradiation means, the temperature of the substrate measured by the first radiation thermometer after the shutter member is inserted into the light shielding position is the predetermined temperature. And a control means for controlling the first light irradiating means so as to irradiate the substrate with flash light when the temperature is lowered to a temperature. The heat treatment apparatus according to claim 6, wherein
The first light irradiation means includes a flash lamp,
The heat treatment apparatus, wherein the second light irradiation means includes a halogen lamp.

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