JP7266458B2 - Heat treatment equipment - Google Patents

Description

The present invention relates to a heat treatment apparatus for heating a thin precision electronic substrate such as a semiconductor wafer (hereinafter simply referred to as "substrate") by irradiating the substrate with flash light.

Flash lamp annealing (FLA), which heats a semiconductor wafer in an extremely short time, has attracted attention in the manufacturing process of semiconductor devices. Flash lamp annealing uses a xenon flash lamp (hereinafter simply referred to as a "flash lamp" to mean a xenon flash lamp) to irradiate the surface of the semiconductor wafer with flash light, so that only the surface of the semiconductor wafer is extremely annealed. It is a heat treatment technology that raises the temperature in a short time (several milliseconds or less).

The radiation spectral distribution of the xenon flash lamp is from the ultraviolet region to the near-infrared region, the wavelength is shorter than that of the conventional halogen lamp, and it almost matches the fundamental absorption band of the silicon semiconductor wafer. Therefore, when the semiconductor wafer is irradiated with flash light from the xenon flash lamp, it is possible to rapidly raise the temperature of the semiconductor wafer with little transmitted light. In addition, it has been found that only the vicinity of the surface of the semiconductor wafer can be selectively heated by flash light irradiation for a very short period of several milliseconds or less.

Such flash lamp annealing is used in processes that require very short heating times, such as activation of impurities typically implanted in semiconductor wafers. By irradiating the surface of a semiconductor wafer into which impurities have been implanted by ion implantation with flash light from a flash lamp, the surface of the semiconductor wafer can be heated to the activation temperature for a very short period of time, and the impurities can be deeply diffused. Therefore, only impurity activation can be performed without causing the activation of the impurities.

In a lamp annealing apparatus using such a flash lamp, heat treatment may be performed in a reduced pressure atmosphere or in an atmosphere of a reactive gas such as ammonia (NH ₃ ). For this reason, an O-ring is used as a sealing member to airtightly seal the chamber containing the semiconductor wafer. Specifically, for example, an O-ring is interposed between the side wall of the metal chamber and the quartz window to seal the inside of the chamber. Since the O-ring is made of resin and has a relatively low heat resistance, it is necessary to take measures to suppress the temperature rise (for example, cooling the chamber using a cooling fluid) when using it in a heat treatment apparatus.

In addition, when the O-ring is used in a heat treatment apparatus using a flash lamp, an extremely strong flash light is momentarily irradiated, so the O-ring is not deteriorated due to heat, but rather an O-ring due to strong flash light irradiation. Surface deterioration of the ring becomes a problem. In particular, when heat treatment is performed in a reduced-pressure atmosphere, the chamber structure needs to be a pressure-resistant structure, and it becomes necessary to increase the thickness of the quartz window that closes the opening of the chamber. When the quartz window is thickened, the flash light can easily enter the quartz window during flash light irradiation, and the flash light can reach the O-ring more easily. Deterioration of the O-ring surface due to flash light irradiation not only impairs the airtightness of the chamber, but also poses a serious problem in that the deteriorated O-ring becomes a source of gas and particles.

For this reason, Patent Literature 1 proposes a technique in which a part of the peripheral portion of the quartz window that contacts the O-ring is made of opaque quartz. Since the opaque quartz blocks the flash light, if part of the peripheral edge of the quartz window that contacts the O-ring is made of opaque quartz, the flash light is prevented from reaching the O-ring when the flash light is irradiated, thereby preventing the O-ring from reaching the O-ring. Surface deterioration can be prevented.

JP 2016-184716 A

However, it is difficult to weld opaque quartz to a part of the quartz window made of transparent quartz, which causes problems such as an increase in manufacturing cost and a longer delivery time. Therefore, there is a demand for a countermeasure using a method with higher productivity.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a heat treatment apparatus capable of preventing deterioration of an O-ring due to flash light irradiation with a simple structure.

In order to solve the above-mentioned problems, the invention of claim 1 provides a heat treatment apparatus for heating a substrate by irradiating the substrate with flash light, comprising a chamber for housing the substrate and a substrate held in the chamber. a holding part, a flash lamp provided outside the chamber on one side of the chamber, a quartz window covering an opening on the one side of the chamber, and a side wall of the chamber and a peripheral edge of the quartz window. an O-ring sandwiched between the quartz window and the lower surface; and a window pressing member that presses the upper surface of the peripheral edge portion of the quartz window toward the side wall of the chamber, wherein the upper surface of the peripheral edge portion is the quartz window. It is characterized by a tapered surface such that the thickness becomes thinner toward the outer peripheral end.

According to a second aspect of the present invention, in the heat treatment apparatus according to the first aspect of the invention, a surface of the window pressing member facing the quartz window is black.

According to the invention of claim 3, in the heat treatment apparatus according to the invention of claim 2, black alumite or black nickel plating is formed on the facing surface of the window pressing member.

According to the first to third aspects of the invention, since the upper surface of the peripheral portion of the quartz window is tapered so that the thickness decreases toward the outer peripheral edge of the quartz window, the flash light entering the quartz window is The amount of light reaching the O-ring can be reduced by the internal reflection of the light, and deterioration of the O-ring due to flash light irradiation can be prevented with a simple configuration.

In particular, according to the second aspect of the invention, since the opposing surface of the window pressing member facing the quartz window is black, the flash light emitted from the upper surface of the peripheral portion of the quartz window is prevented from re-entering the quartz window due to reflection. can be suppressed, and the deterioration of the O-ring can be prevented more reliably.

1 is a vertical cross-sectional view showing the configuration of a heat treatment apparatus according to the present invention; FIG. It is a perspective view which shows the whole external appearance of a holding|maintenance part. 4 is a plan view of the susceptor; FIG. 4 is a cross-sectional view of the susceptor; FIG. It is a top view of a transfer mechanism. It is a side view of a transfer mechanism. FIG. 4 is a plan view showing the arrangement of a plurality of halogen lamps; FIG. 4 is a partially enlarged view showing the structure near the peripheral edge of the upper chamber window of the first embodiment; FIG. 4 is a diagram showing the correlation between the incident angle in quartz and the output light ratio; FIG. 11 is a partially enlarged view showing the structure of the vicinity of the peripheral edge of the upper chamber window of the second embodiment;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<First embodiment>
First, the configuration of the heat treatment apparatus according to the present invention will be described. FIG. 1 is a vertical cross-sectional view showing the configuration of a heat treatment apparatus 1 according to the present invention. The heat treatment apparatus 1 of FIG. 1 is a flash lamp annealing apparatus that heats a disk-shaped semiconductor wafer W as a substrate by irradiating the semiconductor wafer W with flash light. Although the size of the semiconductor wafer W to be processed is not particularly limited, it is, for example, φ300 mm or φ450 mm. In addition, in FIG. 1 and subsequent figures, the dimensions and numbers of each part are exaggerated or simplified as necessary for easy understanding.

The heat treatment apparatus 1 includes a chamber 6 containing a semiconductor wafer W, a flash heating section 5 containing a plurality of flash lamps FL, and a halogen heating section 4 containing a plurality of halogen lamps HL. A flash heating section 5 is provided on the upper side of the chamber 6, and a halogen heating section 4 is provided on the lower side. The heat treatment apparatus 1 also includes a holding unit 7 that holds the semiconductor wafer W in a horizontal posture inside the chamber 6, a transfer mechanism 10 that transfers the semiconductor wafer W between the holding unit 7 and the outside of the apparatus, Prepare. Further, the heat treatment apparatus 1 includes a control section 3 that controls each operation mechanism provided in the halogen heating section 4, the flash heating section 5, and the chamber 6 to perform the heat treatment of the semiconductor wafer W. As shown in FIG.

The chamber 6 is configured by mounting chamber windows made of quartz on the upper and lower sides of a cylindrical chamber side portion 61 . The chamber side part 61 has a substantially cylindrical shape with upper and lower openings, the upper opening being closed by an upper chamber window 63, and the lower opening being closed by a lower chamber window 64. ing. The upper chamber window 63 forming the ceiling of the chamber 6 is a disc-shaped member made of quartz and functions as a quartz window through which the flash light emitted from the flash heating unit 5 is transmitted into the chamber 6 . A lower chamber window 64 forming the floor of the chamber 6 is also a disk-shaped member made of quartz and functions as a quartz window through which the light from the halogen heating unit 4 is transmitted into the chamber 6 .

The heat treatment apparatus 1 of this embodiment is a vacuum-compatible apparatus, and the chamber 6 also has a pressure-resistant structure that can withstand vacuum. Specifically, the upper chamber window 63 and the lower chamber window 64 are made thicker than those of the normal pressure flash lamp annealing apparatus (for example, 20 mm or more). An O-ring is sandwiched between the upper chamber window 63 and the lower chamber window 64 and the chamber side portion 61 to seal the interior of the chamber 6, which will be described later.

A reflecting ring 68 is attached to the upper part of the inner wall surface of the chamber side part 61, and a reflecting ring 69 is attached to the lower part. Both the reflecting rings 68 and 69 are formed in an annular shape. The upper reflector ring 68 is attached by fitting from the upper side of the chamber side 61 . On the other hand, the lower reflecting ring 69 is attached by fitting from the lower side of the chamber side portion 61 and fastening with screws (not shown). That is, both the reflecting rings 68 and 69 are detachably attached to the chamber side portion 61 . A space inside 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 reflective rings 68 and 69 is defined as a thermal processing space 65 .

A concave portion 62 is formed in the inner wall surface of the chamber 6 by attaching the reflecting rings 68 and 69 to the chamber side portion 61 . That is, the recess 62 is formed by the central portion of the inner wall surface of the chamber side portion 61 where the reflecting rings 68 and 69 are not attached, the lower end surface of the reflecting ring 68, and the upper end surface of the reflecting ring 69. . The concave portion 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. The chamber side portion 61 and the reflecting rings 68, 69 are made of a metallic material (for example, stainless steel) having excellent strength and heat resistance.

A transfer opening (furnace port) 66 for transferring the semiconductor wafer W into and out of the chamber 6 is formed in the chamber side portion 61 . The transport opening 66 can be opened and closed by a gate valve 185 . The conveying opening 66 is communicated with the outer peripheral surface of the recess 62 . Therefore, when the gate valve 185 opens the transfer opening 66 , the semiconductor wafer W can be transferred from the transfer opening 66 to the heat treatment space 65 through the recess 62 and transferred 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 side portion 61 is provided with a through hole 61a. A radiation thermometer 20 is attached to a portion of the outer wall surface of the chamber side portion 61 where the through hole 61a is provided. The through hole 61 a is a cylindrical hole for guiding infrared light emitted from the lower surface of a semiconductor wafer W held by a susceptor 74 to be described later to the radiation thermometer 20 . The through-hole 61 a is inclined with respect to the horizontal direction so that the axis in the through-hole direction intersects the main surface of the semiconductor wafer W held by the susceptor 74 . A transparent window 21 made of a barium fluoride material that transmits infrared light in a wavelength range measurable by the radiation thermometer 20 is attached to the end of the through hole 61 a facing the heat treatment space 65 .

A gas supply hole 81 for supplying a processing gas 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 above the recess 62 and may be provided in the reflection ring 68 . The gas supply hole 81 is communicated with a gas supply pipe 83 through an annular buffer space 82 formed inside the side wall of the chamber 6 . The gas supply pipe 83 is connected to a process gas supply source 85 . A valve 84 is inserted in the middle of the path of the gas supply pipe 83 . When valve 84 is opened, process gas is delivered from process gas supply 85 to buffer space 82 . The processing gas that has flowed into the buffer space 82 flows so as to expand in the buffer space 82 , which has 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 . As the processing gas, an inert gas such as argon (Ar), helium (He), nitrogen (N ₂ ), or oxygen (O ₂ ), hydrogen (H ₂ ), chlorine (Cl ₂ ), hydrogen chloride (HCl ), ozone (O ₃ ), ammonia (NH ₃ ), etc. can be used.

On the other hand, a gas exhaust hole 86 for exhausting the gas in the heat treatment space 65 is formed in the lower part of the inner wall of the chamber 6 . The gas exhaust hole 86 is formed below the recess 62 and may be provided in the reflecting ring 69 . The gas exhaust hole 86 is communicated with a gas exhaust pipe 88 through an annular buffer space 87 formed inside the side wall of the chamber 6 . The gas exhaust pipe 88 is connected to the exhaust section 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.

The evacuation section 190 has a vacuum pump. Without closing the valve 84 to supply the gas to the heat treatment space 65, the exhaust part 190 is operated to open the valve 89 to exhaust the gas in the heat treatment space 65 and reduce the heat treatment space 65 to a vacuum of less than atmospheric pressure. can be reduced to On the other hand, by opening the valve 84 to supply the processing gas to the heat treatment space 65 and operating the exhaust part 190 to open the valve 89, the atmosphere in the heat treatment space 65 can be replaced.

A gas exhaust pipe 191 for exhausting the gas in the heat treatment space 65 is also connected to the tip of the transfer opening 66 . A gas exhaust pipe 191 is connected to an exhaust section 190 via a valve 192 . By opening the valve 192 , the gas within the chamber 6 is evacuated through the transfer opening 66 .

FIG. 2 is a perspective view showing the overall appearance of the holding portion 7. As shown in FIG. The holding portion 7 includes a base ring 71 , a connecting portion 72 and a susceptor 74 . The base ring 71, the connecting portion 72 and the susceptor 74 are all made of quartz. That is, the entire holding portion 7 is made of quartz.

The base ring 71 is an arc-shaped quartz member that is partly missing from an annular ring. This missing portion is provided to prevent interference between the transfer arm 11 of the transfer mechanism 10 and the base ring 71, which will be described later. The base ring 71 is supported by the wall surface of the chamber 6 by being placed on the bottom surface of the recess 62 (see FIG. 1). A plurality of connecting portions 72 (four in this embodiment) are erected on the upper surface of the base ring 71 along the circumferential direction of the annular shape. The connecting portion 72 is also a quartz member and is fixed to the base ring 71 by welding.

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

A guide ring 76 is installed on the peripheral edge of the upper surface of the holding plate 75 . The guide ring 76 is an annular member having an inner diameter larger than the diameter of the semiconductor wafer W. As shown in FIG. For example, when the diameter of the semiconductor wafer W is φ300 mm, the inner diameter of the guide ring 76 is φ320 mm. The inner circumference of the guide ring 76 is tapered such that it widens upward from the holding plate 75 . The guide ring 76 is made of quartz similar to the holding plate 75 . The guide ring 76 may be welded to the upper surface of the holding plate 75, or may be fixed to the holding plate 75 by a separately processed pin or the like. Alternatively, the holding plate 75 and the guide ring 76 may be processed as an integral member.

A region of the upper surface of the holding plate 75 inside the guide ring 76 serves as a planar holding surface 75a for holding the semiconductor wafer W. As shown in FIG. A plurality of substrate support pins 77 are erected on the holding surface 75 a of the holding plate 75 . In this embodiment, a total of 12 substrate support pins 77 are erected at 30° intervals along a circle concentric with the outer circumference of the holding surface 75a (the inner circumference of the guide ring 76). The diameter of the circle in which the 12 substrate support pins 77 are arranged (the distance between the opposing substrate support pins 77) is smaller than the diameter of the semiconductor wafer W. 270 mm in shape). Each substrate support pin 77 is made of quartz. The plurality of substrate support pins 77 may be provided on the upper surface of the holding plate 75 by welding, or may be processed integrally with the holding plate 75 .

Returning to FIG. 2, the four connecting portions 72 erected on the base ring 71 and the peripheral portion of the holding plate 75 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 . The holder 7 is attached to the chamber 6 by supporting the base ring 71 of the holder 7 on the wall surface of the chamber 6 . When the holding portion 7 is attached to the chamber 6, the holding plate 75 of the susceptor 74 assumes a horizontal posture (a posture in which the normal line coincides with the vertical direction). That is, the holding surface 75a of the holding plate 75 becomes a horizontal surface.

The semiconductor wafer W carried into the chamber 6 is placed and held in a horizontal posture on the susceptor 74 of the holding part 7 mounted in the chamber 6 . At this time, the semiconductor wafer W is held by the susceptor 74 while being supported by twelve substrate supporting pins 77 erected on the holding plate 75 . More strictly, the upper ends of the 12 substrate support pins 77 are in contact with the lower surface of the semiconductor wafer W to support the semiconductor wafer W. As shown in FIG. Since the height of the 12 substrate support pins 77 (the distance from the upper end of the substrate support pin 77 to the holding surface 75a of the holding plate 75) is uniform, the semiconductor wafer W can be held in a horizontal posture by the 12 substrate support pins 77. can support.

Also, the semiconductor wafer W is supported by a plurality of substrate support pins 77 at a predetermined distance from the holding surface 75a of the holding plate 75. As shown in FIG. The thickness of the guide ring 76 is greater than the height of the board support pins 77 . Accordingly, the guide ring 76 prevents the semiconductor wafer W supported by the plurality of substrate support pins 77 from being displaced in the horizontal direction.

Further, as shown in FIGS. 2 and 3, the holding plate 75 of the susceptor 74 is formed with an opening 78 penetrating vertically. The opening 78 is provided so that the radiation thermometer 20 receives radiation light (infrared light) emitted from the lower surface of the semiconductor wafer W. As shown in FIG. That is, the radiation thermometer 20 receives light emitted from the lower surface of the semiconductor wafer W through the transparent window 21 mounted in the opening 78 and the through hole 61a of the chamber side portion 61, and measures the temperature of the semiconductor wafer W. Measure. Further, the holding plate 75 of the susceptor 74 is formed with four through holes 79 through which the lift pins 12 of the transfer mechanism 10 (to be described later) penetrate to transfer the semiconductor wafer W. As shown in FIG.

FIG. 5 is a plan view of the transfer mechanism 10. FIG. 6 is a side view of the transfer mechanism 10. FIG. The transfer mechanism 10 includes two transfer arms 11 . The transfer arm 11 has an arc shape along the generally annular concave portion 62 . Two lift pins 12 are erected on each transfer arm 11 . The transfer arm 11 and lift pins 12 are made of quartz. Each transfer arm 11 is rotatable by a horizontal movement mechanism 13 . The horizontal movement mechanism 13 moves the pair of transfer arms 11 to the transfer operation position (solid line position in FIG. It is horizontally moved to and from the retracted position (the two-dot chain line position in FIG. 5) that does not overlap in plan view. As the horizontal movement mechanism 13, each transfer arm 11 may be rotated by an individual motor. It may be something that moves.

Also, the pair of transfer arms 11 is vertically moved together with the horizontal movement mechanism 13 by the lifting mechanism 14 . When the lifting mechanism 14 raises the pair of transfer arms 11 to the transfer operation position, a total of four lift pins 12 pass through the through holes 79 (see FIGS. 2 and 3) drilled in the susceptor 74, and the lift pins 12 protrudes from the upper surface of the susceptor 74 . On the other hand, when the lifting mechanism 14 lowers the pair of transfer arms 11 to the transfer operation position and removes the lift pins 12 from the through-holes 79, the horizontal movement mechanism 13 moves the pair of transfer arms 11 so as to open 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 section 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 . An exhaust mechanism (not shown) is also provided in the vicinity of the portion where the drive section (horizontal movement mechanism 13 and lifting mechanism 14) of the transfer mechanism 10 is provided, and the atmosphere around the drive section of the transfer mechanism 10 is 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 composed of a plurality of (30 in this embodiment) xenon flash lamps FL inside a housing 51, and a lamp above the light source. and a reflector 52 provided to cover the . A lamp light emission window 53 is attached to the bottom of the housing 51 of the flash heating unit 5 . The lamp light emission window 53 forming the floor of the flash heating unit 5 is a plate-shaped quartz window made of quartz. By installing the flash heating unit 5 above the chamber 6 , the lamp light emission window 53 faces the upper chamber window 63 . The flash 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 an elongated cylindrical shape, and the longitudinal direction of each flash lamp FL is along the main surface of the semiconductor wafer W held by the holding portion 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 area in which the plurality of flash lamps FL are arranged is larger than the planar size of the semiconductor wafer W. As shown in FIG.

The xenon flash lamp FL is composed of a cylindrical glass tube (discharge tube) in which xenon gas is sealed and an anode and a cathode connected to a capacitor at both ends of the glass tube (discharge tube); and an attached trigger electrode. Since xenon gas is an electrical insulator, electricity does not flow in the glass tube under normal conditions even if electric charges are accumulated in the capacitor. However, when a high voltage is applied to the trigger electrode to break down the insulation, the electricity stored in the capacitor instantly flows into the glass tube, and the xenon atoms or molecules are excited at that time to emit light. 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 millisecond to 100 milliseconds. It has the characteristic of being able to irradiate extremely strong light compared to the light source. That is, the flash lamp FL is a pulsed light emitting lamp that instantaneously emits light in an extremely short time of less than 1 second. The light emission time of the flash lamp FL can be adjusted by the coil constant of the lamp power source that supplies power to the flash lamp FL.

Moreover, the reflector 52 is provided above the plurality of flash lamps FL so as to cover them as a whole. The basic function of the reflector 52 is to reflect the flash light emitted from the plurality of flash lamps FL to the heat treatment space 65 side. The reflector 52 is made of an aluminum alloy plate, and its surface (the surface facing the flash lamp FL) is roughened by blasting.

The halogen heating unit 4 provided below the chamber 6 incorporates a plurality of (40 in this embodiment) halogen lamps HL inside a housing 41 . The halogen heating unit 4 heats the semiconductor wafer W by irradiating the heat treatment space 65 with light from the lower side of the chamber 6 through the lower chamber window 64 using a plurality of halogen lamps HL.

FIG. 7 is a plan view showing the arrangement of multiple halogen lamps HL. The 40 halogen lamps HL are arranged in two upper and lower stages. Twenty halogen lamps HL are arranged in the upper stage near the holding part 7, and twenty halogen lamps HL are arranged in the lower stage farther from the holding part 7 than the upper stage. Each halogen lamp HL is a rod-shaped lamp having an elongated cylindrical shape. The 20 halogen lamps HL in both the upper stage and the lower stage 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 portion 7 (that is, along the horizontal direction). there is 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 both the upper and lower stages is higher in the region facing the peripheral portion than in the region facing the central portion of the semiconductor wafer W held by the holding portion 7. there is That is, in both the upper and lower stages, the arrangement pitch of the halogen lamps HL is shorter in the peripheral portion than in the central portion of the lamp arrangement. Therefore, it is possible to irradiate a larger amount of light to the peripheral portion of the semiconductor wafer W, which tends to cause a temperature drop during heating by light irradiation from the halogen heating unit 4 .

A group of halogen lamps HL in the upper stage and a group of halogen lamps HL in the lower stage are arranged so as to cross each other in a grid pattern. That is, a total of 40 halogen lamps HL are arranged such that the longitudinal direction of the 20 halogen lamps HL arranged in the upper stage and the longitudinal direction of the 20 halogen lamps HL arranged in the lower stage are perpendicular to each other. there is

The halogen lamp HL is a filament-type light source that emits light by turning the filament incandescent by energizing the filament arranged inside the glass tube. Inside the glass tube, a gas obtained by introducing a small amount of a halogen element (iodine, bromine, etc.) into an inert gas such as nitrogen or argon is sealed. By introducing a halogen element, it becomes possible to set the temperature of the filament to a high temperature while suppressing breakage of the filament. Therefore, the halogen lamp HL has characteristics that it has a longer life than a normal incandescent lamp and can continuously irradiate strong light. That is, the halogen lamp HL is a continuous lighting lamp that continuously emits light for at least one second. Further, since the halogen lamp HL is a rod-shaped lamp, it has a long life. By arranging the halogen lamp HL along the horizontal direction, the radiation efficiency to the semiconductor wafer W above is excellent.

In addition, a reflector 43 is provided below the two-stage halogen lamp HL in the housing 41 of the halogen heating unit 4 (FIG. 1). The reflector 43 reflects the light emitted from the plurality of halogen lamps HL to the heat treatment space 65 side.

FIG. 8 is a partially enlarged view showing the structure in the vicinity of the peripheral portion of the upper chamber window 63 of the first embodiment. In order to keep the heat treatment space 65 in the chamber 6 airtight, the upper chamber window 63 and the side wall 61 of the chamber 6 are sealed by an O-ring 91 . The O-ring 91 is made of resin having excellent heat resistance (for example, white Viton (registered trademark)). An annular groove 611 is formed in the upper end of the substantially cylindrical chamber side portion 61 , and an O-ring 91 is fitted in the groove 611 . The cross-sectional diameter of the O-ring 91 is larger than the depth of the groove 611 . Then, the upper chamber window 63 is placed on the O-ring 91 fitted in the groove 611 to press the O-ring 91 . Further, an O-ring (not shown) is sandwiched between the window pressing member 67 and the peripheral edge portion upper surface 631 of the upper chamber window 63, and the window pressing member 67 is screwed to the chamber side portion 61, thereby closing the upper chamber window 63. is pressed toward the upper end of the chamber side portion 61 from above. As a result, the O-ring 91 is sandwiched between the lower surface 632 of the peripheral edge portion of the upper chamber window 63 and the upper end portion of the chamber side portion 61 so as to be in close contact with each other. By pressing the upper chamber window 63 with the window pressing member 67 , the upper opening of the chamber 6 is sealed with the O-ring 91 . The window pressing member 67 is made of aluminum, which has excellent resistance to flash light from the flash lamp FL. As with the upper opening, the lower opening of the chamber 6 is also sealed by sandwiching an O-ring (not shown) between the lower chamber window 64 and the chamber side portion 61 .

In the first embodiment, the peripheral edge upper surface 631 of the upper chamber window 63 is tapered (inclined). More precisely, the top surface 631 of the peripheral edge portion is a tapered surface such that the thickness of the upper chamber window 63 gradually decreases from the center side of the upper chamber window 63 toward the outer peripheral edge. The taper angle β between the peripheral edge portion upper surface 631 and the upper surface of the upper chamber window 63 excluding the peripheral edge portion upper surface 631 can be set to an appropriate value, and is, for example, 10° in this embodiment.

A facing surface 671 of the window pressing member 67 facing the peripheral edge portion upper surface 631 of the upper chamber window 63 is black alumite treated. The black alumite treatment is a treatment to blacken the facing surface 671 using a black dye after the alumite treatment of the aluminum window pressing member 61 . Since the facing surface 671 of the window pressing member 67 is formed of black alumite and is black, the reflectance of the facing surface 671 is 5% or less.

Returning to FIG. 1 , the control unit 3 controls the various operating mechanisms provided in the heat treatment apparatus 1 . The hardware configuration of the control unit 3 is the same as that of a general computer. That is, the control unit 3 includes a CPU that is a circuit that performs various arithmetic processing, 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, and control software and data. Equipped with a magnetic disk for storage. The processing in the heat treatment apparatus 1 proceeds as the CPU of the control unit 3 executes a predetermined processing program.

In addition to the above configuration, the heat treatment apparatus 1 prevents excessive temperature rise of the halogen heating section 4, the flash heating section 5, and the chamber 6 due to thermal energy generated from the halogen lamps HL and the flash lamps FL during the heat treatment of the semiconductor wafer W. Therefore, it has various cooling structures. For example, the walls of the chamber 6 are provided with water cooling pipes (not shown). The halogen heating unit 4 and the flash heating unit 5 have an air-cooling structure in which heat is exhausted by forming a gas flow inside. 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 part 5 and the upper chamber window 63 .

Next, a procedure for processing the semiconductor wafer W in the heat treatment apparatus 1 having the above configuration will be briefly described. The type of semiconductor wafer W to be processed by the heat treatment apparatus 1 of the present embodiment is not particularly limited. there is The processing procedure of the heat treatment apparatus 1 described below proceeds as the control unit 3 controls each operating mechanism of the heat treatment apparatus 1 .

First, the valve 84 for air supply is opened, and the valves 89 and 192 for exhaust are opened to start supplying and exhausting air to and from 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 . Further, when the valve 89 is opened, the gas inside the chamber 6 is exhausted from the gas exhaust hole 86 . As a result, the nitrogen gas supplied from the upper portion of the heat treatment space 65 in the chamber 6 flows downward and is exhausted from the lower portion of the heat treatment space 65, thereby replacing the heat treatment space 65 with a nitrogen gas atmosphere. Further, the gas in the chamber 6 is exhausted from the transfer opening 66 by opening the valve 192 . Furthermore, the atmosphere around the drive section of the transfer mechanism 10 is also exhausted by an exhaust mechanism (not shown).

Subsequently, the gate valve 185 is opened to open the transfer opening 66 , and the semiconductor wafer W is carried into the heat treatment space 65 in the chamber 6 through the transfer opening 66 by the transfer robot outside the apparatus. At this time, there is a risk that the atmosphere outside the apparatus will be involved as the semiconductor wafer W is loaded. Involvement of the external atmosphere can be minimized.

The semiconductor wafer W carried in by the transfer robot advances to a position directly above the holding part 7 and stops there. 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 holding plate 75 of the susceptor 74 through the through holes 79 . receives the semiconductor wafer W. At this time, the lift pins 12 rise above the upper ends of the substrate support pins 77 .

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 . As the pair of transfer arms 11 descends, the semiconductor wafer W is transferred from the transfer mechanism 10 to the susceptor 74 of the holding section 7 and held from below in a horizontal posture. The semiconductor wafer W is held by the susceptor 74 while being supported by a plurality of substrate support pins 77 erected on a holding plate 75 . The semiconductor wafer W is held by the holding portion 7 with the surface on which the high dielectric constant film is formed as the upper surface. A predetermined gap is formed between the back surface (main surface opposite to the front surface) of the semiconductor wafer W supported by the plurality of substrate support pins 77 and the holding surface 75 a of the holding plate 75 . The pair of transfer arms 11 that have descended below the susceptor 74 are retracted by the horizontal movement mechanism 13 to the retracted position, that is, to the inside of the recess 62 .

After the semiconductor wafer W is carried into the chamber 6 and the transfer opening 66 is closed, the valve 84 is closed while the exhaust part 190 is operated, and the nitrogen gas is exhausted from the heat treatment space 65 in the chamber 6 to perform the heat treatment. Space 65 is evacuated below atmospheric pressure. After that, the valve 84 is opened again to supply ammonia from the processing gas supply source 85 to the heat treatment space 65 to form an ammonia atmosphere in the chamber 6 . Even after the ammonia atmosphere is formed, the inside of the chamber 6 is kept under a reduced pressure atmosphere below the atmospheric pressure.

After the semiconductor wafer W is held from below in a horizontal posture by the susceptor 74 of the holding unit 7 made of quartz, the 40 halogen lamps HL of the halogen heating unit 4 are lit all at once to perform preheating (assist heating). ) is started. Halogen light emitted from the halogen lamps HL passes through the lower chamber window 64 and the susceptor 74 made of quartz, and irradiates the lower surface of the semiconductor wafer W. As shown in FIG. By receiving light irradiation from the halogen lamp HL, the entire semiconductor wafer W including the high dielectric constant film is preheated and the temperature rises. Since the transfer arm 11 of the transfer mechanism 10 is retracted inside the recess 62, it does not interfere with the heating by the halogen lamp HL.

The temperature of the semiconductor wafer W is measured by the radiation thermometer 20 when preheating is performed by the halogen lamp HL. Infrared light emitted from the lower surface of the semiconductor wafer W held by the susceptor 74 through the opening 78 is received by the radiation thermometer 20 through the transparent window 21 to measure the temperature of the wafer during heating. The measured temperature of the semiconductor wafer W is transmitted to the controller 3 . The control unit 3 monitors whether or not the temperature of the semiconductor wafer W, which is heated by light irradiation from the halogen lamps HL, has reached a predetermined preheating temperature T1 (first temperature), and controls the output of the halogen lamps HL. to control. That is, the control unit 3 feedback-controls the output of the halogen lamp HL based on the measured value by the radiation thermometer 20 so that the temperature of the semiconductor wafer W reaches the preheating temperature T1. The preheating temperature T1 is 300° C. or higher and 600° C. or lower, and is 450° C. in this embodiment.

After the temperature of the semiconductor wafer W reaches the preheating temperature T1, the controller 3 temporarily maintains the semiconductor wafer W at the preheating temperature T1. Specifically, the control unit 3 feedback-controls the output of the halogen lamp HL so that the temperature of the semiconductor wafer W measured by the radiation thermometer 20 maintains the preheating temperature T1.

By performing such preheating using the halogen lamps HL, the temperature of the entire semiconductor wafer W is uniformly raised to the preheating temperature T1. In the stage of preheating by the halogen lamps HL, the temperature of the peripheral portion of the semiconductor wafer W, where heat is more likely to be released, tends to be lower than that of the central portion. The region facing the peripheral portion of the semiconductor wafer W is higher than the region facing the central portion. For this reason, the amount of light irradiated to the peripheral portion of the semiconductor wafer W, which tends to cause heat dissipation, is increased, and the in-plane temperature distribution of the semiconductor wafer W in the preheating stage can be made uniform.

When the temperature of the semiconductor wafer W reaches the preheating temperature T1 and a predetermined time has passed, the flash lamps FL of the flash heating unit 5 irradiate the surface of the semiconductor wafer W with flash light. At this time, part of the flash light emitted from the flash lamp FL goes directly into the chamber 6, and the other part is once reflected by the reflector 52 and then goes into the chamber 6. Flash heating of the semiconductor wafer W is effected by irradiation.

Since the flash heating is performed by irradiating flash light (flash light) from the flash lamps FL, the surface temperature of the semiconductor wafer W can be raised in a short time. That is, the flash light emitted from the flash lamp FL has an extremely short irradiation time of about 0.1 millisecond or more and 100 millisecond or less, in which the electrostatic energy previously stored in the capacitor is converted into an extremely short light pulse. A strong flash. Then, the surface temperature of the semiconductor wafer W flash-heated by the irradiation of flash light from the flash lamps FL instantaneously rises to the processing temperature T2, and then immediately drops rapidly. A processing temperature T2, which is the highest temperature (peak temperature) reached by the surface of the semiconductor wafer W due to flash light irradiation, is 600° C. or higher and 1200° C. or lower, and is 1000° C. in this embodiment. By raising the surface temperature of the semiconductor wafer W to the processing temperature T2 in the ammonia atmosphere, the post-deposition annealing (PDA: Post Deposition Anneal) of the high dielectric constant film formed on the surface is performed.

The halogen lamp HL is extinguished after a predetermined time has elapsed after the flash heating process is completed. As a result, the temperature of the semiconductor wafer W is rapidly lowered from the preheating temperature T1. Further, the ammonia atmosphere is discharged from the heat treatment space 65 in the chamber 6 and the heat treatment space 65 is replaced with a nitrogen atmosphere. The temperature of the semiconductor wafer W during cooling is measured by the radiation thermometer 20 and the measurement result is transmitted to the controller 3 . The control unit 3 monitors whether the temperature of the semiconductor wafer W has decreased to a predetermined temperature based on the measurement result. After the temperature of the semiconductor wafer W is lowered to a predetermined level or less, the pair of transfer arms 11 of the transfer mechanism 10 moves horizontally again from the retracted position to the transfer operation position, thereby moving the lift pins 12 to the susceptor. 74 protrudes from the upper surface of the holding plate 75 to receive the semiconductor wafer W after heat treatment from the susceptor 74 . Subsequently, the transfer opening 66 closed by the gate valve 185 is opened, the semiconductor wafer W placed on the lift pins 12 is transferred out by the transfer robot outside the apparatus, and the semiconductor wafer W is heat-treated in the heat treatment apparatus 1. is completed.

By the way, in the heat treatment apparatus 1 , when flash light is emitted from the flash lamps FL, the flash light incident on the upper chamber window 63 may enter the peripheral portion of the upper chamber window 63 . In particular, in the vacuum-compatible heat treatment apparatus 1 of the present embodiment, the plate thickness of the upper chamber window 63 and the lower chamber window 64 is thicker than that of the normal pressure-compatible flash lamp annealing apparatus. At times, the amount of flash light entering the peripheral portion of the upper chamber window 63 increases. Since the lower chamber window 64 is arranged on the opposite side of the flash lamp FL across the semiconductor wafer W held by the holding part 7, the flash light hardly reaches the lower chamber window 64 even when the flash light is irradiated.

If no special measures are taken to block the entry of flash light, the flash light that has entered the peripheral edge of the upper chamber window 63 will repeat multiple reflections on the peripheral edge surface and reach the O-ring 91 . Become. When the resin O-ring 91 is exposed to strong flash light, the surface of the O-ring 91 deteriorates, not only lowering the airtightness in the chamber 6, but also the deteriorated O-ring 91 becomes a source of gas and particles. may become

For this reason, in the first embodiment, the top surface 631 of the upper chamber window 63 is tapered, and the facing surface 671 of the window pressing member 67 is black. The operation of such a configuration will be described with reference to FIG. Since the refractive index _n1 of air is 1 and the refractive index _n2 of quartz is 1.46, the flash light emitted from the flash lamp FL is refracted when entering the upper chamber window 63 of quartz. do. The flash light entering the upper chamber window 63 reaches the lower surface of the upper chamber window 63 at an incident angle _α1 and is reflected. The reflection angle at this time is also _α1 .

The flash light reflected by the lower surface of the upper chamber window 63 reaches the peripheral upper surface 631 . Since the peripheral edge portion upper surface 631 is a tapered surface, the incident angle _α2 of the flash light to the peripheral edge portion upper surface 631 is smaller than the incident angle _α1 . Specifically, the incident angle _α2 is smaller than the incident angle _α1 by the taper angle β. In the example shown in FIG. 8, the flash light entering the upper chamber window 63 is reflected only once by the lower surface of the upper chamber window 63 and reaches the peripheral upper surface 631. The light may reach the upper surface 631 of the peripheral portion after repeating multiple reflections between the upper surface and the lower surface of the window 63 . Also in this case, since the upper and lower surfaces of the upper chamber window 63 are parallel, the incident angle of the flash light to the upper surface 631 of the peripheral portion is _α2 .

FIG. 9 is a diagram showing the correlation between the incident angle in quartz and the output light ratio. Light entering the quartz does not exit the quartz at all when the angle of incidence is greater than about 43°. In other words, the light is totally reflected on the quartz surface. On the other hand, 90% or more of the light entering quartz exits from the quartz when the incident angle is less than about 35°.

Since the flash light emitted from the flash lamp FL is refracted when entering the quartz upper chamber window 63 from the air, the incident angle _α1 is always smaller than 43°. The incident angle _α2 of the flash light with respect to the upper surface 631 of the peripheral portion is smaller than the incident angle _α1 by the taper angle β, and in the example of this embodiment, the taper angle β=10°, so the incident angle _α2 is greater than 33°. become smaller. Therefore, 90% or more of the flash light reaching the upper surface 631 of the peripheral portion is emitted from the upper chamber window 63 . As a result, most of the flash light that enters the upper chamber window 63 and reaches the top surface 631 of the peripheral portion is emitted outward from the top surface 631 of the peripheral portion, and is internally reflected by the top surface 631 of the peripheral portion. The amount of light will be very low. Therefore, the amount of flash light reaching the O-ring 91 due to internal reflection within the upper chamber window 63 can be suppressed to a small amount. From the viewpoint of suppressing the light reflected by the upper surface 631 of the peripheral edge portion from reaching the O-ring 91, the larger the taper angle β, the better. and

Further, as shown in FIG. 8, the flash light emitted outward from the peripheral upper surface 631 of the upper chamber window 63 is incident on the facing surface 671 of the window pressing member 67 . The facing surface 671 of the window pressing member 67 is black alumite treated and has a reflectance of 5% or less. Therefore, most of the flash light incident on the opposing surface 671 of the window pressing member 67 is absorbed by the black opposing surface 671, and the flash light reflected by the opposing surface 671 and re-entering the upper chamber window 63 is very small. small amount. As a result, the amount of flash light that is once emitted outward from the peripheral edge portion upper surface 631 of the upper chamber window 63, reflected by the opposing surface 671, and then reaches the O-ring 91 by re-entering can be suppressed to a small amount.

Furthermore, the angle of reflection of the reflected light that reaches the top surface 631 of the peripheral portion and is reflected is _α2 , which is smaller than _α1 . Therefore, in the first embodiment, the reflected light from the peripheral edge portion upper surface 631 reaches the O-ring 91 more times than when the peripheral edge portion upper surface 631 is not tapered. The flash light reaching the ring 91 will be more attenuated.

Thus, in the first embodiment, the top surface 631 of the upper chamber window 63 is tapered, and the facing surface 671 of the window pressing member 67 is black. As a result, the amount of internally reflected light of the flash light that enters the upper chamber window 63 and reaches the upper surface 631 of the peripheral edge portion can be reduced, and the amount of light emitted from the upper surface 631 of the peripheral edge portion is reflected by the upper chamber window 63 . It is also possible to suppress the amount of flash light re-entering the . As a result, the amount of flash light reaching the O-ring 91 can be suppressed to a small amount, and deterioration of the O-ring 91 can be prevented. That is, deterioration of the O-ring 91 due to flash light irradiation can be prevented with a simple configuration in which the peripheral upper surface 631 of the upper chamber window 63 is tapered and the facing surface 671 of the window pressing member 67 is black.

<Second embodiment>
Next, a second embodiment of the invention will be described. The overall configuration of the heat treatment apparatus of the second embodiment is substantially the same as that of the first embodiment. Further, the processing procedure of the semiconductor wafer W in the second embodiment is also the same as in the first embodiment. The second embodiment differs from the first embodiment in the structure of the peripheral portion of the upper chamber window 63 .

FIG. 10 is a partially enlarged view showing the structure in the vicinity of the peripheral portion of the upper chamber window 63 of the second embodiment. In FIG. 10, the same reference numerals as in FIG. 8 denote the same elements as in the first embodiment. In the second embodiment, the upper chamber window 63 and the window pressing member 67 are sealed by an O-ring 91 in order to keep the heat treatment space 65 in the chamber 6 airtight.

The upper chamber window 63 of the second embodiment is a disc-shaped quartz member and does not have a tapered surface. The outer peripheral side surface 633 of the upper chamber window 63 is a cylindrical surface formed at the outer peripheral end of the upper chamber window 63 and perpendicular to the upper and lower surfaces of the upper chamber window 63 . The upper chamber window 63 is supported by the chamber side portion 61 via a metal support piece (not shown) and is pressed from above by a window pressing member 67 via an O-ring (not shown). An annular groove 672 is formed inside the window pressing member 67 and an O-ring 91 is fitted in the groove 672 . The outer peripheral side surface 633 of the upper chamber window 63 contacts the O-ring 91 fitted in the groove 672 . That is, an O-ring 91 for sealing is sandwiched between the outer peripheral side surface 633 of the upper chamber window 63 and the window pressing member 67 .

As in the first embodiment, the flash light emitted from the flash lamp FL is refracted when entering the upper chamber window 63 of quartz. The flash light entering the upper chamber window 63 reaches the lower surface of the upper chamber window 63 at an incident angle α and is reflected. The angle of reflection at this time is α. The light reflected by the lower surface of the upper chamber window 63 reaches the upper surface of the upper chamber window 63 and is reflected again. In this way, multiple reflections are repeated between the upper and lower surfaces of the upper chamber window 63 and the flash light reaches the outer peripheral side surface 633 . Since the upper surface and the lower surface of the upper chamber window 63 are parallel to each other, the incident angle and reflection angle of the flash light during repeated multiple reflections between the upper surface and the lower surface are all α.

The flash light reaching the outer peripheral side surface 633 of the upper chamber window 63 is incident on the outer peripheral side surface 633 at an incident angle γ. Since the upper and lower surfaces of the upper chamber window 63 are perpendicular to the outer peripheral side surface 633, the relationship α+γ=90° is established between the incident angle α and the incident angle γ.

As described above, the flash light emitted from the flash lamp FL is refracted when entering the upper chamber window 63, so the incident angle α is always smaller than 43°. Then the angle of incidence γ is greater than 47°. As shown in FIG. 9, light traveling through the quartz upper chamber window 63 is totally reflected by the outer peripheral side surface 633 when the incident angle γ is greater than 47°. That is, the flash light reaching the outer peripheral side surface 633 of the upper chamber window 63 is not emitted from the outer peripheral side surface 633 at all. As a result, the flash light entering the upper chamber window 63 is prevented from being emitted from the outer peripheral side surface 633 and reaching the O-ring 91 .

In the second embodiment, an O-ring 91 is sandwiched between the outer peripheral side surface 633 of the upper chamber window 63 and the window pressing member 67 . The flash light entering the upper chamber window 63 always reaches the outer peripheral side surface 633 at an incident angle γ greater than 47°. Therefore, the flash light is not totally reflected by the outer peripheral side surface 633 and emitted from the outer peripheral side surface 633 . As a result, flash light does not reach the O-ring 91, and deterioration of the O-ring 91 can be prevented. That is, it is possible to prevent deterioration of the O-ring 91 due to flash light irradiation with a simple structure in which the O-ring 91 is sandwiched between the outer peripheral side surface 633 and the window pressing member 67 .

However, there is a possibility that the flash light entering through the gap between the upper surface of the upper chamber window 63 and the window pressing member 67 will turn around and reach the O-ring 91 . For this reason, in the second embodiment as well, by making the facing surface of the window pressing member 67 facing the upper chamber window 63 black, such reflection of the flash light is suppressed and the flash light does not reach the O-ring 91 . You can more reliably prevent it from reaching you.

<Modification>
Although 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 scope of the invention. For example, in the above embodiment, the opposing surface 671 of the window pressing member 67 is blackened by black alumite treatment, but instead of this, the opposing surface 671 may be plated with black nickel to be black. Alternatively, the facing surface 671 of the window pressing member 67 may be blackened by another method. In short, the facing surface 671 should be black with a reflectance of 5% or less.

Further, although the structure of the peripheral portion of the upper chamber window 63 has been described in the first embodiment or the second embodiment, the peripheral portion of the lower chamber window 64 may also have the same structure. If the peripheral portion of the lower chamber window 64 has the same structure as the upper chamber window 63 of the above embodiment, it is possible to prevent deterioration of the O-ring due to light irradiation from the halogen lamp HL.

In addition, in the first embodiment, the peripheral upper surface 631 of the upper chamber window 63 is tapered and the opposing surface 671 of the window pressing member 67 is black. However, it is possible to prevent deterioration of the O-ring 91 by reducing the amount of flash light reaching the O-ring 91 to some extent. However, the deterioration of the O-ring 91 due to flash light irradiation can be more reliably prevented by the first embodiment.

Further, in the above embodiment, the flash heating unit 5 is provided with 30 flash lamps FL, but the present invention is not limited to this, and the number of flash lamps FL can be any number. . Also, the flash lamp FL is not limited to a xenon flash lamp, and may be a krypton flash lamp. Also, the number of halogen lamps HL provided in the halogen heating unit 4 is not limited to 40, and may be an arbitrary number.

Further, in the above embodiment, the semiconductor wafer W is preheated by using the filament type halogen lamp HL as the continuous lighting lamp that continuously emits light for one second or longer. Preheating may be performed by using a discharge type arc lamp (for example, a xenon arc lamp) as a continuous lighting lamp instead of the halogen lamp HL.

Further, substrates to be processed by the heat treatment apparatus according to the present invention are not limited to semiconductor wafers, and may be glass substrates used for flat panel displays such as liquid crystal display devices or substrates for solar cells. Also, the technique according to the present invention may be applied to joining metal and silicon, crystallization of polysilicon, or the like.

REFERENCE SIGNS LIST 1 heat treatment apparatus 3 control unit 4 halogen heating unit 5 flash heating unit 6 chamber 7 holding unit 10 transfer mechanism 63 upper chamber window 64 lower chamber window 65 heat treatment space 67 window pressing member 74 susceptor 75 holding plate 77 substrate support pin 91 O Ring 631 Peripheral upper surface 633 Peripheral side surface 671 Opposite surface FL Flash lamp HL Halogen lamp W Semiconductor wafer

Claims (3)

A heat treatment apparatus for heating a substrate by irradiating the substrate with flash light,
a chamber containing the substrate;
a holding unit that holds the substrate in the chamber;
a flash lamp provided outside the chamber and on one side of the chamber;
a quartz window covering the one side opening of the chamber;
an O-ring sandwiched between the side wall of the chamber and the lower surface of the peripheral edge of the quartz window;
a window pressing member that presses the upper surface of the peripheral portion of the quartz window toward the side wall of the chamber;
with
The heat treatment apparatus, wherein the upper surface of the peripheral edge portion is a tapered surface whose thickness decreases toward the outer peripheral edge of the quartz window. In the heat treatment apparatus according to claim 1,
A heat treatment apparatus according to claim 1, wherein a surface of the window pressing member facing the quartz window is black. In the heat treatment apparatus according to claim 2,
A heat treatment apparatus, wherein the opposing surface of the window pressing member is plated with black alumite or black nickel.

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