JP2005005667A - Heat treatment apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat treatment apparatus in which a seal member can be prevented from being deteriorated by light radiation in heat treatment. <P>SOLUTION: An O ring 17 that is the seal member, is held between a translucent plate 61 and a side plate 63 comprising a main body part of a heat treatment chamber. A flange 10 is provided in the upper part of the side plate 63. The flange 10 is made of aluminum and provided to cover the peripheral edge of the upper surface of the translucent plate 61. On the other hand, the peripheral edge of the lower surface of the translucent plate 61 is roughened into a light shielding plane 61a by honing. Flash light L1 emitted from a flash lamp 691 that is comparatively close to the O ring 17, to the O ring 17 is shielded by the flange 10. On the other hand, flash light L2 emitted from a flash lamp 692 that is comparatively away from the O ring 17, to the O ring 17 is temporarily made incident to the light transmission plate 61 and the shielded by the roughened light shielding plane 61a. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

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

  Conventionally, in an ion activation process of a semiconductor wafer after ion implantation, a heat treatment apparatus such as a lamp annealing apparatus using a halogen lamp has been used. In such a heat treatment apparatus, the semiconductor wafer is ion-activated 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.

  Generally, in a lamp annealing apparatus using such a halogen lamp, various gases are often introduced into the heat treatment chamber, and an O-ring is used as a seal member for making the heat treatment chamber airtight. Since the O-ring is made of resin and has a relatively low heat-resistant temperature, it is necessary to suppress a temperature rise due to radiant heat from the halogen lamp. For this reason, a lamp annealing apparatus that cools an O-ring during heat treatment using gas or a cooling fluid has been proposed (see, for example, Patent Document 1). There is also a lamp annealing apparatus in which a resin sheet is sandwiched between a refrigerant jacket and an O-ring in order to conduct heat efficiently to the refrigerant (see, for example, Patent Document 2).

  However, even when ion activation of a semiconductor wafer is performed using a heat treatment apparatus that raises the temperature of the substrate at a speed of several hundred degrees per second, the profile of ions implanted into the semiconductor wafer is reduced, that is, due to heat It has been found that a phenomenon occurs in which ions diffuse. When such a phenomenon occurs, even if ions are implanted at a high concentration on the surface of the semiconductor wafer, the ions after implantation are diffused, so that ions must be implanted more than necessary. Has occurred.

  In order to solve the above-mentioned problems, the surface of the semiconductor wafer is irradiated with flash light using a xenon flash lamp or the like, so that only the surface of the semiconductor wafer into which ions are implanted is raised in a very short time (several milliseconds or less). Techniques for heating have been proposed (see, for example, Patent Documents 3 and 4). If the temperature is raised for a very short time with a xenon flash lamp, there is not enough time for ions to diffuse, so only ion activation is performed without the profile of the ions implanted in the semiconductor wafer being distorted. Can do it.

Japanese Patent Laid-Open No. 2002-9010 JP-A-9-326366 JP 59-169125 A JP 63-166219 A

  However, since the xenon flash lamp heats the irradiated object by flash light irradiation for a moment, when the flash light is irradiated from the xenon flash lamp to the O ring in the heat treatment chamber, light irradiation is performed rather than the entire O ring deteriorates due to heat. There is a phenomenon that the surface deteriorates due to. Deterioration of the O-ring surface is a serious problem in that airtightness in the heat treatment chamber is impaired.

  This invention is made | formed in view of the said subject, and it aims at providing the heat processing apparatus which can prevent deterioration of the sealing member by the light irradiation at the time of heat processing.

  In order to solve the above-described problems, a first aspect of the present invention provides a heat treatment apparatus for heating a substrate by irradiating the substrate with light, the light source having a lamp and the light source provided below the light source. A chamber having an upper chamber window through which the emitted light is transmitted, holding means for holding the substrate in a substantially horizontal position in the chamber, and a chamber installed in the chamber to maintain the inside of the chamber in an airtight state. A sealing member; and a light shielding unit that blocks light emitted from the lamp and traveling toward the sealing member.

  According to a second aspect of the present invention, in the heat treatment apparatus according to the first aspect of the present invention, the seal member is sandwiched between the chamber window and the main body of the chamber along the peripheral edge of the lower surface of the chamber window. An O-ring is used, and the light shielding means blocks light from the lamp passing through the chamber window toward the O-ring.

  Further, the invention of claim 3 is the heat treatment apparatus according to claim 2, wherein the light shielding means includes an opaque flange provided on the main body so as to cover a peripheral surface of the upper surface of the chamber window. Yes.

  According to a fourth aspect of the present invention, in the heat treatment apparatus according to the third aspect of the present invention, the flange is made of aluminum.

  The invention according to claim 5 is the heat treatment apparatus according to any one of claims 2 to 4, wherein the light shielding means has a light shielding surface in which the peripheral edge of the lower surface of the chamber window is roughened by a honing process. Is included.

  Further, the invention of claim 6 is the heat treatment apparatus according to claim 3 or claim 4, wherein the light shielding means further includes a light shielding wall erected on the body portion on the inner peripheral side of the O-ring. Included.

  According to a seventh aspect of the present invention, in the heat treatment apparatus according to the sixth aspect of the present invention, the light shielding wall is fitted into a groove formed in a peripheral portion of the lower surface of the chamber window.

  The invention according to claim 8 is the heat treatment apparatus according to claim 2, wherein the light shielding means includes an opaque flange provided on the main body so as to cover an upper peripheral edge of the chamber window, and the chamber window. The labyrinth mechanism provided with the groove | channel carved in the lower surface peripheral part of this is included.

  According to a ninth aspect of the present invention, in the heat treatment apparatus according to the eighth aspect of the present invention, the labyrinth mechanism further includes a light shielding wall provided by being fitted in the groove.

  The invention of claim 10 is the heat treatment apparatus according to any one of claims 1 to 9, wherein the lamp is a xenon flash lamp, and the holding means pre-heats the substrate to be held by the holding means. It has.

  According to the first aspect of the present invention, since the light shielding means for blocking the light emitted from the lamp and directed to the sealing member is provided, the light does not reach the sealing member, and the deterioration of the sealing member due to light irradiation during the heat treatment is prevented. can do.

  According to the invention of claim 2, since the light blocking means blocks light from the lamp passing through the chamber window and going to the O ring, it is possible to prevent the O ring from being deteriorated due to light irradiation during heat treatment.

  According to the invention of claim 3, the light shielding means includes an opaque flange provided on the main body so as to cover the peripheral edge of the upper surface of the chamber window, and the flange prevents light from reaching the O-ring. it can.

  According to the invention of claim 4, since the flange is made of aluminum, light resistance can be imparted to the flange itself.

  According to the invention of claim 5, since the light shielding means includes the light shielding surface having the lower peripheral edge of the chamber window roughened by the honing process, the light shielding surface can block light from reaching the O-ring. .

  According to the sixth aspect of the present invention, since the light shielding means includes the light shielding wall erected on the inner peripheral side from the O ring, the light reaching the O ring can be blocked by the light shielding wall.

  According to the invention of claim 7, since the light shielding wall is fitted in the groove formed on the peripheral edge of the lower surface of the chamber window, the light passing through the chamber window toward the O-ring is blocked by the light shielding wall. be able to.

  Further, according to the invention of claim 8, the labyrinth mechanism in which the light shielding means includes an opaque flange provided so as to cover the peripheral edge of the upper surface of the chamber window and a groove formed in the peripheral edge of the lower surface of the chamber window. Therefore, the labyrinth mechanism can block light from reaching the O-ring.

  According to the invention of claim 9, since the labyrinth mechanism is provided with the light shielding wall, the arrival of light to the O-ring can be more reliably blocked.

  According to the invention of claim 10, since the lamp is a xenon flash lamp and includes an assist heating means for preheating the substrate held by the holding means, the heat treatment apparatus using the xenon flash lamp can Flash does not reach the member, and deterioration of the seal member due to light irradiation during heat treatment can be prevented.

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

<1. First Embodiment>
1 and 2 are side sectional views showing the structure of a heat treatment apparatus according to the present invention. This heat treatment apparatus is an apparatus for performing heat treatment of a substrate such as a semiconductor wafer by flash light from a xenon flash lamp.

  This heat treatment apparatus includes a light transmitting plate 61, a bottom plate 62, and a pair of side plates 63 and 64, and includes a chamber 65 for housing the semiconductor wafer W and heat-treating it. The translucent plate 61 constituting the upper part of the chamber 65 is made of, for example, a material having infrared transparency such as quartz, and functions as a chamber window that transmits light emitted from the light source 5 and guides it into the chamber 65. is doing. Further, the bottom plate 62 and the side plates 63 and 64 constituting the main body of the chamber 65 are made of a metal material having excellent strength and heat resistance, such as stainless steel.

  Further, the bottom plate 62 is provided with support pins 70 that pass through a heat diffusion plate 73 and a heating plate 74 described later to support the semiconductor wafer W from its lower surface. Further, the side plate 64 is formed with an opening 66 for carrying in and carrying out the semiconductor wafer W. The opening 66 can be opened and closed by a gate valve 68 that rotates about a shaft 67. The semiconductor wafer W is loaded into the chamber 65 by a transfer robot (not shown) with the opening 66 released. Further, when the semiconductor wafer W is heat-treated in the chamber 65, the opening 66 is closed by the gate valve 68.

  The chamber 65 is provided below the light source 5. The light source 5 includes a plurality (29 in the present embodiment) of xenon flash lamps 69 (hereinafter also simply referred to as “flash lamps 69”) and a reflector 71. The plurality of flash lamps 69 are rod-shaped lamps each having a long cylindrical shape, and are arranged in a plane parallel to each other such that the longitudinal direction thereof is along the horizontal direction. The reflector 71 is disposed above the plurality of flash lamps 69 so as to cover them entirely.

  The xenon flash lamp 69 includes a glass tube in which xenon gas is sealed and an anode and a cathode connected to a capacitor at both ends thereof, and a trigger electrode wound around an external portion of the glass tube. Is provided. Since xenon gas is an electrical insulator, electricity does not flow into the glass tube under normal conditions. 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 the xenon flash lamp 69, the electrostatic energy stored in advance is converted into an extremely short light pulse of 0.1 millisecond to 10 millisecond. It has the feature that it can.

  A light diffusing plate 72 is disposed between the light source 5 and the translucent plate 61. As the light diffusion plate 72, a surface of quartz glass as an infrared transmitting material subjected to light diffusion processing is used.

  Part of the light emitted from the flash lamp 69 passes directly through the light diffusing plate 72 and the light transmitting plate 61 toward the chamber 65. Further, another part of the light emitted from the flash lamp 69 is once reflected by the reflector 71, then passes through the light diffusing plate 72 and the light transmitting plate 61 and goes into the chamber 65.

  A heating plate 74 and a heat diffusion plate 73 are provided in the chamber 65. The heat diffusion plate 73 is attached to the upper surface of the heating plate 74. Further, a position shift prevention pin 75 of the semiconductor wafer W is attached to the surface of the heat diffusion plate 73.

The heating plate 74 is for preheating (assist heating) the semiconductor wafer W. The heating plate 74 is made of aluminum nitride and has a configuration in which a heater and a sensor for controlling the heater are housed. On the other hand, the heat diffusing plate 73 diffuses the heat energy from the heating plate 74 and uniformly preheats the semiconductor wafer W. As the material of the heat diffusion plate 73, a material having a relatively low thermal conductivity such as sapphire (Al ₂ O ₃ : aluminum oxide) or quartz is employed.

  The heat diffusing plate 73 and the heating plate 74 are configured to move up and down between the loading / unloading position of the semiconductor wafer W shown in FIG. 1 and the heat treatment position of the semiconductor wafer W shown in FIG. .

  That is, the heating plate 74 is connected to the moving plate 42 via the cylindrical body 41. The moving plate 42 can be moved up and down by being guided by a guide member 43 supported by a bottom plate 62 of the chamber 65. A fixed plate 44 is fixed to the lower end portion of the guide member 43, and a motor 40 that rotationally drives a ball screw 45 is disposed at the central portion of the fixed plate 44. The ball screw 45 is screwed with a nut 48 connected to the moving plate 42 via connecting members 46 and 47. Therefore, the heat diffusion plate 73 and the heating plate 74 can be moved up and down between the loading / unloading position of the semiconductor wafer W shown in FIG. 1 and the heat treatment position of the semiconductor wafer W shown in FIG. it can.

  The loading / unloading position of the semiconductor wafer W shown in FIG. 1 is placed on the support pin 70 by placing the semiconductor wafer W loaded from the opening 66 using a transfer robot (not shown). This is the position where the heat diffusion plate 73 and the heating plate 74 are lowered so that the completed semiconductor wafer W can be carried out from the opening 66. In this state, the upper end of the support pin 70 passes through the through holes formed in the heat diffusion plate 73 and the heating plate 74 and protrudes upward from the surface of the heat diffusion plate 73.

  On the other hand, the heat treatment position of the semiconductor wafer W shown in FIG. 2 is a position where the heat diffusion plate 73 and the heating plate 74 are raised above the upper ends of the support pins 70 in order to perform heat treatment on the semiconductor wafer W. In the process in which the heat diffusion plate 73 and the heating plate 74 are raised from the loading / unloading position of FIG. 1 to the heat treatment position of FIG. 2, the semiconductor wafer W placed on the support pins 70 is received by the heat diffusion plate 73 and its lower surface. Is supported by the surface of the heat diffusing plate 73, and is held in a horizontal posture at a position in the chamber 65 close to the translucent plate 61. Conversely, in the process in which the heat diffusion plate 73 and the heating plate 74 are lowered from the heat treatment position to the carry-in / carry-out position, the semiconductor wafer W supported by the heat diffusion plate 73 is transferred to the support pins 70.

  In a state where the thermal diffusion plate 73 and the heating plate 74 that support the semiconductor wafer W are raised to the heat treatment position, the translucent plate 61 is located between the semiconductor wafer W held by them and the light source 5. Note that the distance between the heat diffusion plate 73 and the light source 5 at this time can be adjusted to an arbitrary value by controlling the rotation amount of the motor 40.

  Further, the liner 20 is fitted along the chamber wall surface of the chamber 65. The liner 20 is not fixed to the chamber 65 and is detachable. The liner 20 is made of, for example, quartz, and is formed in a bottomed cylindrical shape so as to cover the inner wall surfaces of the side plates 63 and 64 and the bottom plate 62. The liner 20 may be a split body that can be separated into a cylindrical portion and a bottom portion, or may be integrally molded.

  In addition, the heater reflector 30 is provided around the heating plate 74, the heat diffusion plate 73, and the cylindrical body 41 that supports them, except for the upper surface of the heat diffusion plate 73. The heater reflector 30 is also a quartz member. The heater reflector 30 prevents heat energy from the heating plate 74 from being transmitted to other than the heat diffusion plate 73.

  Further, between the bottom plate 62 of the chamber 65 and the moving plate 42, a telescopic bellows 77 is disposed so as to surround the cylindrical body 41 and maintain the chamber 65 in an airtight body. When the heat diffusing plate 73 and the heating plate 74 are raised to the heat treatment position, the bellows 77 contracts, and when the heat diffusion plate 73 and the heating plate 74 are lowered to the loading / unloading position, the bellows 77 is expanded and the atmosphere in the chamber 65 is increased. Shut off from outside atmosphere.

  In the side plate 63 opposite to the opening 66 in the chamber 65, an introduction path 78 connected to the on-off valve 80 is formed. The introduction path 78 is for introducing a gas necessary for processing, for example, an inert nitrogen gas, into the chamber 65. On the other hand, a discharge passage 79 connected to the on-off valve 81 is formed in the opening 66 in the side plate 64. The discharge path 79 is for discharging the gas in the chamber 65, and is connected to an exhaust means (not shown) via the on-off valve 81.

  By the way, in order to introduce a gas necessary for processing while maintaining the inside of the chamber 65 in a clean atmosphere, the atmosphere in the chamber 65 and the external atmosphere must be shut off to maintain the inside of the chamber 65 in an airtight state. . For this purpose, as described above, a bellows 77 is provided between the bottom plate 62 and the moving plate 42. On the other hand, since there is a possibility that the space between the quartz translucent plate 61 and the metal side plates 63 and 64 may be a leak source, a resin O-ring 17 is provided as a sealing member.

  FIG. 3 is an enlarged view of the seal portion indicated by A in FIGS. 1 and 2. In the side plates 63 and 64 of the chamber 65, the ring groove 15 is formed in an annular shape at a position facing the peripheral surface of the lower surface of the translucent plate 61. A resin O-ring 17 is provided in an annular shape along the ring groove 15. The depth of the ring groove 15 is slightly smaller than the diameter r of the cross section of the O-ring 17. Therefore, the O-ring 17 is sandwiched between the translucent plate 61 and the main body portion of the chamber 65 along the peripheral edge of the lower surface of the translucent plate 61, thereby maintaining the inside of the chamber 65 in an airtight state. Become.

  On the other hand, the flange 10 is provided on the upper part of the side plates 63 and 64. The flange 10 is made of aluminum, and is provided so as to cover the periphery of the upper surface of the translucent plate 61. The inner diameter of the flange 10 is smaller than the inner diameter of the O-ring 17. Aluminum is opaque to the flash light emitted from the flash lamp 69 and has a property that it is not easily damaged by the flash light from the flash lamp 69 compared to other metals. Since the opaque flange 10 is provided so as to cover the peripheral edge of the upper surface of the translucent plate 61, even if flash light is irradiated from the vicinity immediately above the O-ring 17, it is blocked by the flange 10 and reaches the O-ring 17. There is no.

  Moreover, in 1st Embodiment, the lower surface peripheral part of the translucent board 61 is made into the light-shielding surface 61a roughened by the honing process. FIG. 4 is a view of the translucent plate 61 as viewed from the lower surface side. The light shielding surface 61 a is formed in an annular shape along the peripheral edge of the lower surface of the translucent plate 61. The light shielding surface 61a may be formed so as to cover at least the entire O-ring 17.

  Here, the honing process is a kind of surface roughening process, and there are dry and wet processing methods. In the wet (liquid) honing treatment, a powdery abrasive (abrasive grain) is suspended in a liquid such as water, and then sprayed onto the masked translucent plate 61 at a high speed to roughen the periphery. Is the method. In the case of the wet honing treatment, the surface roughness can be controlled by the liquid spraying pressure, the speed, the amount, type, shape, size, hardness, specific gravity, suspension concentration and the like of the abrasive.

  On the other hand, the dry honing process is a method in which an abrasive is sprayed at a high speed on the lower surface of the translucent plate 61 masked with air to roughen the surface. Also in the case of the dry honing treatment, the surface roughness can be controlled by the air blowing pressure, speed, amount of abrasive, type, shape, size, hardness, specific gravity and the like.

  In any of the above methods, particles such as silicon carbide, alumina, zirconia, stainless steel, iron, glass beads, and plastic shot can be used as the abrasive. And the light-shielding surface 61a formed by the roughening by a honing process exhibits what is called a satin pattern. Therefore, even if the flashlight 69 enters the light-transmitting plate 61 and the flashlight reaches the light shielding surface 61a, it is prevented from being scattered by the roughened light shielding surface 61a and reaching the O-ring 17.

  In addition, the outer surface of the liner 20 is roughened by performing the honing process similar to the above, and the inner surface is made smoother than the outer surface without performing the honing process. Further, honing treatment similar to the above is performed on both surfaces of the heater reflector 30.

  Next, the heat treatment operation of the semiconductor wafer W by the heat treatment apparatus having the above configuration will be described. A semiconductor wafer W to be processed in this heat treatment apparatus is a semiconductor wafer after ion implantation.

  In this heat treatment apparatus, in a state where the heat diffusing plate 73 and the heating plate 74 are arranged at the loading / unloading positions of the semiconductor wafer W shown in FIG. It is carried in and placed on the support pin 70. When the loading of the semiconductor wafer W is completed, the opening 66 is closed by the gate valve 68. Thereafter, the heat diffusion plate 73 and the heating plate 74 are raised to the heat treatment position of the semiconductor wafer W shown in FIG. 2 by driving the motor 40 to hold the semiconductor wafer W in a horizontal posture. Further, the on-off valve 80 and the on-off valve 81 are opened to form a nitrogen gas flow in the chamber 65.

  The heat diffusing plate 73 and the heating plate 74 are preheated to a predetermined temperature by the action of a heater built in the heating plate 74. For this reason, in a state where the heat diffusion plate 73 and the heating plate 74 are raised to the heat treatment position of the semiconductor wafer W, the semiconductor wafer W is preheated by contacting the heat diffusion plate 73 in a heated state, and the semiconductor wafer W The temperature gradually increases.

  In this state, the semiconductor wafer W is continuously heated by the heat diffusion plate 73. When the temperature of the semiconductor wafer W rises, a temperature sensor (not shown) always monitors whether or not the surface temperature of the semiconductor wafer W has reached the preheating temperature T1.

  The preheating temperature T1 is, for example, about 200 ° C. to 600 ° C. Even if the semiconductor wafer W is heated to such a preheating temperature T1, ions implanted into the semiconductor wafer W will not diffuse.

  Eventually, when the surface temperature of the semiconductor wafer W reaches the preheating temperature T1, the flash lamp 69 is turned on to perform flash heating. The lighting time of the flash lamp 69 in this flash heating process is a time of about 0.1 to 10 milliseconds. Thus, in the flash lamp 69, the electrostatic energy stored in advance is converted into such an extremely short light pulse, so that an extremely strong flash light is irradiated.

  By such flash heating, the surface temperature of the semiconductor wafer W instantaneously reaches the temperature T2. This temperature T2 is a temperature necessary for the ion activation treatment of the semiconductor wafer W at about 1000 ° C. to 1100 ° C. When the surface of the semiconductor wafer W is heated to such a processing temperature T2, ions implanted into the semiconductor wafer W are activated.

  At this time, since the surface temperature of the semiconductor wafer W is raised to the processing temperature T2 in an extremely short time of about 0.1 to 10 milliseconds, ion activation in the semiconductor wafer W is completed in a short time. . Therefore, the ions implanted into the semiconductor wafer W do not diffuse, and it is possible to prevent the phenomenon that the profile of the ions implanted into the semiconductor wafer W is lost. Since the time required for ion activation is extremely short compared with the time required for ion diffusion, the ion activation is performed even for a short time in which no diffusion of about 0.1 millisecond to 10 millisecond occurs. Complete.

  Further, before the flash lamp 69 is turned on to heat the semiconductor wafer W, the surface temperature of the semiconductor wafer W is heated to the preheating temperature T1 of about 200 ° C. to 600 ° C. using the heating plate 74. The flash lamp 69 makes it possible to quickly raise the temperature of the semiconductor wafer W to the processing temperature T2 of about 1000 ° C. to 1100 ° C.

  After the flash heating process is completed, the heat diffusion plate 73 and the heating plate 74 are lowered to the loading / unloading position of the semiconductor wafer W shown in FIG. Is released. Then, the semiconductor wafer W placed on the support pins 70 is carried out by a transfer robot (not shown). As described above, a series of heat treatment operations is completed.

  When the flash lamp 69 is turned on to heat the semiconductor wafer W, there is also light that passes from the flash lamp 69 through the translucent plate 61 toward the O-ring 17. As described above, since the flash lamp 69 emits a strong flash light in a very short time, the surface of the flash lamp 69 is significantly deteriorated when the O ring 17 is irradiated with the flash light.

  Therefore, in the first embodiment, the flange 10 is provided, and the peripheral edge of the lower surface of the translucent plate 61 is roughened by a honing process to form the light shielding surface 61a, thereby passing the translucent plate 61 from the flash lamp 69. In this way, the flashing toward the O-ring 17 is blocked. In FIG. 3, the flash light L <b> 1 emitted toward the O-ring 17 from the flash lamp 691 that is relatively close to the O-ring 17 among the plurality of flash lamps 69 is blocked by the flange 10. Since the flange 10 is made of aluminum and is opaque to the flash light L 1, the flash light L 1 does not reach the O-ring 17. Further, since aluminum has a property that it is not easily damaged by the flash from the flash lamp 69, the flange 10 itself is prevented from being deteriorated by the flash L1.

  On the other hand, the flash light L2 emitted toward the O-ring 17 from the flash lamp 692 that is relatively far from the O-ring 17 among the plurality of flash lamps 69 cannot be shielded by the flange 10. The flash light L2 is once incident on the translucent plate 61 and then blocked by the roughened light shielding surface 61a. For this reason, the flash L2 is also prevented from reaching the O-ring 17.

  Accordingly, the flash light emitted from all the flash lamps 69 toward the O-ring 17 is shielded by either the flange 10 or the light-shielding surface 61 a and does not reach the O-ring 17. As a result, deterioration of the O-ring 17 due to flash irradiation during heat treatment is prevented.

  The light shielding surface 61a is also a sealing surface that shields light traveling toward the O-ring 17 and keeps the inside of the chamber 65 in an airtight state in contact with the O-ring 17. That is, the light shielding surface 61a must have both light shielding properties and sealing properties. As the degree of roughening of the light-shielding surface 61a increases (as the surface roughness increases), the light-shielding performance is improved, while the sealing performance decreases. Therefore, the surface average roughness (Ra) of the light shielding surface 61a needs to be in the range of 1.0 μm or more and 2.0 μm or less that can achieve both light shielding properties and sealing properties, and in this embodiment, Ra = 1.16 μm.

<2. Second Embodiment>
Next, a second embodiment of the present invention will be described. The heat treatment apparatus of the second embodiment is also an apparatus for performing heat treatment of a substrate such as a semiconductor wafer by flash light from a xenon flash lamp, and the entire configuration and the heat treatment operation of the semiconductor wafer W are the same as those of the first embodiment. Omitted. However, the second embodiment differs from the first embodiment in the structure of the seal portion indicated by A in FIGS. 1 and 2.

  5 and 6 are an enlarged view and a perspective view, respectively, of the seal portion of the second embodiment. As in the first embodiment, ring grooves 15 are formed in the side plates 63 and 64 of the chamber 65 in an annular shape at positions facing the lower peripheral edge of the translucent plate 61, and along the ring grooves 15. A resin O-ring 17 is provided in an annular shape. The O-ring 17 is sandwiched between the translucent plate 61 and the main body of the chamber 65 along the peripheral edge of the lower surface of the translucent plate 61. As a result, the inside of the chamber 65 is maintained in an airtight state.

  A flange 10 is provided on the upper side of the side plates 63 and 64. The flange 10 is made of aluminum, and is provided so as to cover the periphery of the upper surface of the translucent plate 61. The inner diameter of the flange 10 is smaller than the inner diameter of the O-ring 17. Aluminum is opaque to the flash light emitted from the flash lamp 69 and is less susceptible to damage by the flash light from the flash lamp 69 than other metals. Since the opaque flange 10 is provided so as to cover the peripheral edge of the upper surface of the translucent plate 61, even if flash light is irradiated from the vicinity immediately above the O-ring 17, it is blocked by the flange 10 and reaches the O-ring 17. There is no.

  Furthermore, in the second embodiment, the groove 19 is formed in an annular shape on the peripheral edge of the lower surface of the translucent plate 61, and the light shielding wall 18 is provided in an annular shape on the side plates 63 and 64 of the chamber 65. The translucent plate 61 is installed in the chamber 65 so that the light shielding wall 18 is fitted in the groove 19. The diameter of the annular light shielding wall 18 is smaller than the diameter of the O-ring 17. That is, the light shielding wall 18 is erected on the inner peripheral side with respect to the O-ring 17. The O-ring 17 is disposed below the upper end surfaces of the side plates 63 and 64, whereas the light shielding wall 18 is erected above the upper end surfaces of the side plates 63 and 64. 18 is provided on the inner peripheral side above the O-ring 17.

  In the second embodiment, the flange 10 is provided so as to cover the top of the O-ring 17, and the light shielding wall 18 is erected on the inner peripheral side above the O-ring 17, whereby the translucent plate 61 is removed from the flash lamp 69. The flash that passes through the O-ring 17 is blocked. That is, in FIG. 5, the flash light L <b> 3 emitted toward the O-ring 17 from the flash lamp 69 relatively close to the O-ring 17 among the plurality of flash lamps 69 is blocked by the flange 10. On the other hand, the flash light L4 emitted toward the O-ring 17 from the flash lamp 69 relatively far from the O-ring 17 among the plurality of flash lamps 69 once enters the light-transmitting plate 61 and is blocked by the light-shielding wall 18.

  As a result, the flashlight emitted from all the flash lamps 69 is shielded by either the flange 10 or the light shielding wall 18 and does not reach the O-ring 17. This prevents the O-ring 17 from being deteriorated due to flash irradiation during heat treatment. In other words, in the second embodiment, the labyrinth mechanism is configured by the flange 10 provided so as to cover the peripheral edge of the upper surface of the translucent plate 61 and the groove 19 formed in the peripheral edge of the lower surface of the translucent plate 61. The light shielding wall 18 is fitted into the groove 19 to shield the flash light emitted from all the flash lamps 69 toward the O-ring 17.

  In addition, in the second embodiment, since the peripheral edge of the lower surface of the translucent plate 61 is smooth, sufficient sealing performance by contact with the O-ring 17 can be obtained.

<3. Third Embodiment>
Next, a third embodiment of the present invention will be described. The heat treatment apparatus of the third embodiment is also an apparatus for performing heat treatment of a substrate such as a semiconductor wafer by flash light from a xenon flash lamp, and is the second embodiment except that a drooping portion 11 is provided at the tip of the flange 10. Is the same.

  FIG. 7 is an enlarged view of a seal portion of the third embodiment. In the third embodiment, in addition to the groove 19, the groove 12 is engraved in an annular shape on the peripheral edge of the upper surface of the translucent plate 61. In addition, a hanging portion 11 is provided that hangs from the tip of the flange 10 provided so as to cover the peripheral edge of the upper surface of the translucent plate 61. The hanging part 11 is fitted in the groove 12. The hanging part 11 is provided further on the inner peripheral side than the light shielding wall 18.

  In the third embodiment, the flashlight emitted toward the O-ring 17 from the flash lamp 69 that is relatively close to the O-ring 17 among the plurality of flash lamps 69 is blocked by the flange 10 and is relatively far from the O-ring 17. The flash emitted from 69 is blocked by the hanging part 11 and the light shielding wall 18. As a result, the flashlight emitted from all the flash lamps 69 is reliably shielded by the flange 10, the hanging portion 11 and the light shielding wall 18, and does not reach the O-ring 17. This prevents the O-ring 17 from being deteriorated due to flash irradiation during heat treatment.

  Further, in the third embodiment, the flange 10 provided so as to cover the upper surface peripheral portion of the translucent plate 61, the groove 19 engraved in the lower surface peripheral portion of the translucent plate 61, and the upper surface peripheral portion are engraved. The groove 12 constitutes a more complex labyrinth mechanism than in the second embodiment. Then, the light shielding wall 18 is fitted in the groove 19 and the hanging part 11 is fitted in the groove 12 so that the flashlight emitted from all the flash lamps 69 toward the O-ring 17 is surely shielded. It is. Further, since a more complicated labyrinth mechanism is realized, it is possible to prevent the flash reflected on the inner wall surface of the flange 10 and the upper end surfaces of the side plates 63 and 64 from reaching the O-ring 17.

<4. Modification>
While the embodiments of the present invention have been described above, the present invention is not limited to the above examples. For example, in the above embodiments, the light source 5 is provided with 29 flash lamps 69. However, the present invention is not limited to this, and the number of flash lamps 69 may be arbitrary.

  Further, the technique according to the present invention can be applied to a heat treatment apparatus that includes another type of lamp (for example, a halogen lamp) instead of the flash lamp 69 in the light source 5 and heats the semiconductor wafer W by light irradiation from the lamp. Can be applied. That is, by providing a light blocking member that blocks light emitted from the lamp and traveling toward the seal member, it is possible to prevent the seal member from being deteriorated due to light irradiation.

  In the first embodiment, the flashes from all the flash lamps 69 to the O-ring 17 are shielded by both the flange 10 and the light shielding surface 61a. However, the light shielding may be performed by only one of them. For example, since the metal flange 10 has a higher light shielding property, only the flange 10 may be provided as long as the flash light directed from all the flash lamps 69 toward the O-ring 17 can be shielded. Further, if the O-ring 17 itself can have a certain level of light resistance, only the light shielding surface 61a may be used.

  In the first embodiment, a light shielding property may be imparted to the inside of the light transmitting plate 61 instead of the light shielding surface 61a. For example, what is necessary is just to give many light bubbles in the peripheral part inside the translucent board 61, and to provide light-shielding property. If a light shielding property is imparted to the inside while making the peripheral surface of the lower surface of the translucent plate 61 a smooth surface, a high light shielding property can be obtained while maintaining a sufficient sealing property with the O-ring 17.

  In the second and third embodiments, the light shielding wall 18 is fitted to the groove 19 to shield the flash light from the flash lamp 69. However, the light shielding property is imparted to the groove 19 by other methods. May be. For example, the inner wall surface of the groove 19 may be colored to give the groove 19 a light shielding property, and the flash light from the flash lamp 69 toward the O-ring 17 may be blocked.

  In each of the above embodiments, 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. Absent. 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 concerning this invention. It is a sectional side view which shows the structure of the heat processing apparatus concerning this invention. It is an enlarged view of the seal part of 1st Embodiment. It is the figure which looked at the translucent board of a 1st embodiment from the undersurface side. It is an enlarged view of the seal part of 2nd Embodiment. It is a perspective view of the seal part of a 2nd embodiment. It is an enlarged view of the seal part of 3rd Embodiment.

Explanation of symbols

5 Light source 10 Flange 11 Hanging portion 12, 19 Groove 15 Ring groove 17 O-ring 18 Shielding wall 20 Liner 30 Heater reflector 61 Translucent plate 61 a Shielding surface 62 Bottom plate 63, 64 Side plate 65 Chamber 69 Flash lamp 71 Reflector 72 Light diffusing plate 73 Thermal diffusion plate 74 Heating plate W Semiconductor wafer

Claims (10)

A heat treatment apparatus for heating a substrate by irradiating the substrate with light,
A light source having a lamp;
A chamber provided below the light source, and provided with a chamber window at the top for transmitting light emitted from the light source;
Holding means for holding the substrate in a substantially horizontal posture in the chamber;
A seal member provided in the chamber and maintaining the inside of the chamber in an airtight state;
Light shielding means for blocking light emitted from the lamp and directed to the seal member;
A heat treatment apparatus comprising: The heat treatment apparatus according to claim 1, wherein
The seal member is an O-ring sandwiched between the chamber window and the main body of the chamber along the lower peripheral edge of the chamber window,
The heat-shielding device, wherein the light-shielding means shields light from the lamp passing through the chamber window and going to the O-ring. The heat treatment apparatus according to claim 2,
The heat-shielding means includes an opaque flange provided on the main body so as to cover a peripheral edge of the upper surface of the chamber window. The heat treatment apparatus according to claim 3, wherein
The heat treatment apparatus characterized in that the flange is made of aluminum. In the heat processing apparatus in any one of Claims 2-4,
The heat-shielding means includes a light-shielding surface obtained by roughening the peripheral surface of the lower surface of the chamber window by a honing process. In the heat treatment apparatus according to claim 3 or 4,
The heat-treating apparatus, wherein the light-shielding means further includes a light-shielding wall erected on the main body on the inner peripheral side of the O-ring. The heat treatment apparatus according to claim 6, wherein
The heat-shielding apparatus is characterized in that the light shielding wall is fitted in a groove formed on a peripheral edge of the lower surface of the chamber window. The heat treatment apparatus according to claim 2,
The light shielding means includes a labyrinth mechanism including an opaque flange provided in the main body so as to cover an upper peripheral edge of the chamber window and a groove formed in a lower peripheral edge of the chamber window. Heat treatment equipment. The heat treatment apparatus according to claim 8, wherein
The heat treatment apparatus, wherein the labyrinth mechanism further includes a light-shielding wall that is fitted in the groove. In the heat treatment apparatus according to any one of claims 1 to 9,
The lamp is a xenon flash lamp;
The heat treatment apparatus is characterized in that the holding means includes assist heating means for preheating the substrate to be held.

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