JP4319433B2 - Heat treatment equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
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”), and in particular, a reflection that reflects flash light emitted from a flash lamp. It relates to the improvement of the board.
[0002]
[Prior art]
Conventionally, in the ion activation process of a semiconductor wafer after ion implantation, flash light emitted from a xenon flash lamp is reflected by a reflector and irradiated on the surface of the semiconductor wafer, so that only the surface of the semiconductor wafer into which ions have been implanted is irradiated. Has been proposed (see, for example, Patent Documents 1 and 2) in which the temperature is raised in a very short time (several milliseconds or less).
[0003]
In such a heat treatment technology, in order to more efficiently irradiate a semiconductor wafer with flash light emitted from a xenon flash lamp and raise the temperature of the semiconductor wafer more efficiently, the xenon flash lamp is applied to the semiconductor wafer. Further, a method of making the distance from the reflecting plate closer can be considered.
[0004]
Here, in the vicinity of the xenon flash lamp, a trigger electrode used for breaking the insulation inside the glass tube of the xenon flash lamp when emitting flash light is disposed. That is, by applying a high voltage to the trigger electrode, the xenon gas sealed inside the glass tube is changed to a plasma state to break the insulating state, thereby causing the xenon flash lamp to emit light. Therefore, in order to further reduce the distance between the xenon flash lamp and the reflector, it is necessary to prevent a leak current that leaks from the trigger electrode toward the reflector when a high voltage is applied.
[0005]
[Patent Document 1]
JP 2001-237195 A [Patent Document 2]
Japanese Patent Laid-Open No. 2002-246328
[Problems to be solved by the invention]
However, the devices of Patent Document 1 and Patent Document 2 do not take measures to prevent the above-described leakage current. Therefore, for safety of the apparatus, the xenon flash lamp cannot be brought close to the reflector, and the temperature of the silicon wafer cannot be increased more efficiently.
[0007]
Therefore, the present invention provides a heat treatment apparatus that heats a substrate by irradiating a flash with the substrate, and efficiently irradiates the semiconductor wafer with the flash emitted from the flash lamp while ensuring the safety of the heat treatment apparatus. An object of the present invention is to provide a heat treatment apparatus.
[0008]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, a first aspect of the present invention is a heat treatment apparatus for heating a substrate by irradiating a flash with the substrate, a holding means for holding the substrate, a light source having a flash lamp, and the flash A reflector disposed on the opposite side of the holding means across the lamp and reflecting flash light emitted from the flash lamp, and disposed in the vicinity of the flash lamp, and by applying a high voltage to the inside of the flash lamp And a trigger part that emits flash light from the flash lamp, and the reflector is electrically insulated from the trigger part by a predetermined insulating material.
[0009]
According to a second aspect of the present invention, in the heat treatment apparatus according to the first aspect, the reflection plate is formed of an electrical insulator.
[0010]
According to a third aspect of the present invention, in the heat treatment apparatus according to the second aspect, the reflector is made of ceramics.
[0011]
According to a fourth aspect of the present invention, there is provided a heat treatment apparatus for heating a substrate by irradiating a flash with the substrate, a holding means for holding the substrate, a light source having a flash lamp, and the flash lamp sandwiched between A reflector disposed on the opposite side of the holding means and reflecting the flash light emitted from the flash lamp, and a reflector disposed on the reflector, the reflector being fixedly supported from a predetermined support site. An interposing member; and a trigger part disposed near the flash lamp and breaking the insulation inside the flash lamp by applying a high voltage to emit flash light from the flash lamp. Is formed of a conductor, and the insertion member is formed of an electrical insulator.
[0012]
The invention according to claim 5 is the heat treatment apparatus according to any one of claims 1 to 4, wherein the trigger portion is disposed between the reflector and the flash lamp. And
[0013]
According to a sixth aspect of the present invention, in the heat treatment apparatus according to any one of the first to fifth aspects, the light source includes a plurality of flash lamps.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
<1. First Embodiment>
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0015]
<1.1. Configuration of heat treatment equipment>
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.
[0016]
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. The bottom plate 62 constituting the chamber 65 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.
[0017]
Further, an opening 66 for carrying in and out the semiconductor wafer W is formed in the side plate 64 constituting the chamber 65. 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.
[0018]
A light source 5 is disposed above the chamber 65 as shown in FIGS. The light source 5 is disposed inside the housing 30 and includes a plurality of (27 in the present embodiment) xenon flash lamps 69 (hereinafter also simply referred to as “flash lamps 69”). The plurality of flash lamps 69 are rod-shaped lamps each having a long cylindrical shape, and are arranged in parallel with each other such that the longitudinal direction thereof is along the horizontal direction (Y-axis direction).
[0019]
FIG. 3 is a side sectional view showing a configuration in the vicinity of the light source 5 of the present embodiment. FIG. 4 is a front view showing a configuration in the vicinity of the flash lamp 69. Xenon gas is sealed in the internal space 39 inside the glass tube of the xenon flash lamp 69. Also, as shown in FIG. 4, an anode 36 and a cathode 37 are disposed at both ends of the internal space 39 of the flash lamp 69, and are connected to the capacitor 35 via wirings 38 (38a, 38b). Yes. Further, as shown in FIGS. 3 and 4, trigger electrodes 31 corresponding to the respective flash lamps 69 are disposed in the vicinity of the respective flash lamps 69 and between the respective flash lamps 69 and the reflector 71. .
[0020]
Here, since the xenon gas sealed in the internal space 39 is an electrical insulator, electricity does not flow into the glass tube in a normal state. However, when a high voltage is applied to the corresponding trigger electrode 31 disposed above each flash lamp 69 via the wiring 33, the xenon gas in the internal space 39 of each flash lamp 69 enters a plasma state, and the internal space 39 Insulation is destroyed. Therefore, electricity stored in the capacitor 35 flows instantaneously in the internal space 39, and the xenon gas is heated by Joule heat at that time, and light is emitted.
[0021]
Thus, in the xenon flash lamp 69, the electrostatic energy stored in advance is converted into an extremely short light pulse of 0.1 to 10 milliseconds, so that it is extremely stronger than a continuously lit light source. It has the feature that it can be irradiated with light. Therefore, in this embodiment, as will be described later, a mechanism for measuring the intensity of light emitted from the flash lamp 69 (not shown in FIGS. 1 and 2 is omitted) is provided in the heat treatment apparatus.
[0022]
The reflector 71 is a reflecting plate that reflects light emitted from the plurality of flash lamps 69, and has an insulating property (electric resistivity: 10 ⁸ Ωcm or more) such as aluminum nitride, alumina (dialuminum trioxide), or the like. It is formed by a process such as sintering using an insulating material. That is, the reflector 71 is formed of an insulating ceramic that is an electrical insulator. As shown in FIGS. 1 and 2, the reflector 71 supports the semiconductor wafer W in a horizontal posture above the plurality of flash lamps 69, that is, at a position close to the translucent plate 61 across the plurality of flash lamps 69. The support pins 70 are held on the opposite side of the plurality of flash lamps 69 so as to cover the entire flash lamps 69.
[0023]
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.
[0024]
Therefore, a part of the light emitted from the flash lamp 69 passes directly through the light diffusion plate 72 and the light transmission plate 61 and goes into 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. Thus, the light emitted from the flash lamp 69 can be efficiently incident into the chamber 65, and the temperature of the semiconductor wafer W held in the chamber 65 can be efficiently increased.
[0025]
The ceramics such as aluminum nitride and alumina described above have heat resistance. Therefore, even when the reflector 71 is heated by receiving the light emitted from the flash lamp 69, the light emitted from the flash lamp 69 can be reflected well.
[0026]
By the way, as a technique for making the semiconductor wafer W held in the chamber 65 more efficiently heated and making the heat distribution of the semiconductor wafer W uniform when the temperature is raised, the flash lamp 69 and the reflector 71 are brought closer to each other. Can be considered. According to this method, the distance between the flash lamp 69 and the reflector 71 can be shortened, and the light emitted above the flash lamp 69 can be reflected more efficiently. Therefore, the light emitted from the flash lamp 69 can be more efficiently incident into the chamber 65 to irradiate the semiconductor wafer W, and the illuminance distribution can be made uniform. As a result, it is possible to increase the temperature more efficiently while maintaining the uniformity of the heat distribution of the semiconductor wafer W during the temperature increase.
[0027]
However, when this method is adopted in a conventional heat treatment apparatus, the distance between the trigger electrode and the reflector disposed in the vicinity of the flash lamp is shortened by bringing the flash lamp and the reflector close to each other. The problem of leakage current that electricity leaks from the reflector to the reflector occurs. That is, in the conventional heat treatment apparatus, the reflector is formed of a conductor such as aluminum or an aluminum alloy. Therefore, when a high voltage is applied to the trigger electrode, a leakage current flows from the trigger electrode toward the reflector of the conductor depending on the distance between the trigger electrode and the reflector. As a result, it is necessary to ensure the safety of the entire heat treatment apparatus.
[0028]
Further, when a leak current flows from the trigger electrode toward the reflector, there is a problem of erroneous light emission in which the trigger electrode erroneously causes a flash lamp other than the flash lamp originally intended to emit light due to the influence of the leak current. Therefore, each of the plurality of flash lamps cannot accurately emit light (for example, each flash lamp has substantially the same timing), and the illuminance of light emitted from the plurality of flash lamps and applied to the semiconductor wafer W The distribution becomes uneven, and as a result, the heat treatment to the semiconductor wafer W cannot be performed satisfactorily.
[0029]
On the other hand, in the heat treatment apparatus of the present embodiment, the reflector 71 is formed of an insulating ceramic. Thereby, the reflector 71 is electrically insulated from the trigger electrode 31, and a leak current flows from the trigger electrode 31 toward the reflector 71 even if the distance between each flash lamp 69 and the reflector 71 is made closer. There is no. Therefore, it is possible to more efficiently irradiate the semiconductor wafer W with the light emitted from the plurality of flash lamps 69 while maintaining the safety of the entire heat treatment apparatus, and to increase the temperature of the semiconductor wafer W more efficiently. can do.
[0030]
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.
[0031]
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.
[0032]
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. .
[0033]
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.
[0034]
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.
[0035]
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.
[0036]
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.
[0037]
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.
[0038]
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.
[0039]
As described above, this heat treatment apparatus is provided with a mechanism for measuring the intensity of light emitted from the flash lamp 69. FIG. 5 is a diagram showing a schematic configuration of the light intensity measurement mechanism. This light intensity measuring mechanism mainly includes a plurality of optical fibers 20 that guide light emitted from the flash lamp 69, a CCD (Charge Coupled Device) 25 that outputs the intensity of the received light as an electric signal, and an electric power output from the CCD 25. And a computer 10 for analyzing signals.
[0040]
One end of each optical fiber 20 is fixed to the reflector 71. FIG. 7 is a view showing the arrangement of the optical fiber 20 with respect to the flash lamp 69. FIG. 8 is an enlarged view showing how the optical fiber 20 is attached to the reflector 71. As shown in FIG. 7, in the present embodiment, three optical fibers 20 are arranged for one flash lamp 69. That is, the flash lamp 69 is a rod-shaped lamp having a long cylindrical shape, and is configured such that the end face of the optical fiber 20 faces the center portion and both end portions of each flash lamp 69. Accordingly, assuming that 27 flash lamps 69 are provided in the light source 5, a total of 81 optical fibers 20 are attached to the reflector 71. Specifically, as shown in FIG. 8, a hole slightly larger than the diameter of the optical fiber 20 is formed in the reflector 71 directly above the flash lamp 69, and one end of the optical fiber 20 is inserted into the hole. The optical fiber 20 is fixed by the mounting jig 21. The material of the optical fiber 20 is made of quartz and is resistant to intense flash light from the flash lamp 69.
[0041]
As shown in FIGS. 7 and 8, a plurality of, for example, 81 optical fibers 20 are attached to the reflector 71, so that the end faces of the optical fibers 20 face the central portion and both end portions of the 27 flash lamps 69. When the flash lamp 69 emits flash light in this state, the emitted light enters the end face of each optical fiber 20 and is guided by the optical fiber 20.
[0042]
On the other hand, the other end of each optical fiber 20 is fixed to a fiber fixing jig 22. The connection mode (arrangement) of the plurality of optical fibers 20 to the fiber fixing jig 22 may be arbitrary according to the shape of the CCD 25. For example, 81 optical fibers 20 may be arranged in a line, or arranged in a rectangular shape. In the present embodiment, 27 optical fibers 20 facing the center portion, one end portion, and the other end portion of the flash lamp 69 are arranged in three rows and fixed to the fiber fixing jig 22. Of course, the light incident from one end surface facing the flash lamp 69 and guided through the optical fiber 20 is emitted from the other end surface without being blocked by the fiber fixing jig 22.
[0043]
A filter 23 is attached to the fiber fixing jig 22. As the filter 23, various types can be adopted depending on the purpose. For example, an ND filter may be employed when the light emitted from the optical fiber 20 is too strong, and a band pass filter may be employed when it is desired to narrow down to a predetermined spectrum. For example, when it is desired to monitor only the spectrum on the ultraviolet side that greatly contributes to flash heating, a bandpass filter that narrows down to the spectrum on the ultraviolet side is employed. Further, a filter coated with a fluorescent paint can be used as the filter 23. Furthermore, a light diffusing plate may be used instead of the filter 23.
[0044]
The CCD 25 is a light receiving element in which photodiodes are arranged in a planar shape and extracts an amount of electricity proportional to accumulated incident light. The CCD 25 is disposed opposite to the fiber fixing jig 22, and the light emitted from the 81 optical fibers 20 and transmitted through the filter 23 can be received by the single CCD 25. A CMOS sensor (Complementary Metal Oxide Semiconductor) or the like may be employed as a light receiving element in place of the CCD 25. Further, a lens coupling system may be disposed between the filter 23 and the CCD 25.
[0045]
The CCD control circuit 27 is a circuit that controls reading of electric charges accumulated in the CCD 25. The electrical signal read from the CCD 25 by the CCD control circuit 27 is transmitted to the computer 10. The computer 10 is attached to the heat treatment apparatus, and its hardware configuration is the same as that of a general computer.
[0046]
FIG. 6 is a block diagram illustrating a configuration of the computer 10. The computer 10 includes a CPU 11 that performs various arithmetic processes, a ROM 12 that is a read-only memory that stores basic programs, a RAM 13 that is a readable and writable memory that stores various information, and a magnetic disk that stores control software and data. 14 is connected to a bus line 19. An A / D converter 15 is connected to the bus line 19. The A / D converter 15 is a circuit that converts an analog electrical signal read from the CCD 25 by the CCD control circuit 27 into digital.
[0047]
Further, the display unit 16 and the input unit 17 are electrically connected to the bus line 19. The display unit 16 is configured using, for example, a liquid crystal display or the like, and displays various information such as processing results and recipe contents. The input unit 17 is configured using, for example, a keyboard, a mouse, and the like, and receives input of commands, parameters, and the like. The operator of the apparatus can input commands and parameters from the input unit 17 while confirming the contents displayed on the display unit 16. Note that the display unit 16 and the input unit 17 may be integrated to form a touch panel.
[0048]
With the configuration as described above, in this embodiment, the light emitted from the flash lamp 69 is guided by the optical fiber 20, the light intensity is measured by the CCD 25, and the obtained measurement result can be analyzed by the computer 10.
[0049]
<1.2. Heat treatment operation>
Next, the heat treatment operation of the semiconductor wafer W by the heat treatment apparatus according to the present invention will be described. A semiconductor wafer W to be processed in this heat treatment apparatus is a semiconductor wafer after ion implantation.
[0050]
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.
[0051]
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.
[0052]
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.
[0053]
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.
[0054]
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.
[0055]
Further, the reflector 71 of the heat treatment apparatus of the present embodiment is formed of an insulating ceramic as described above. As a result, even if the distance between each flash lamp 69 and the reflector 71 is reduced, a leak current does not flow from the trigger electrode 31 toward the reflector 71, and light emitted from each flash lamp 69 is efficiently transmitted to the semiconductor wafer. W can be irradiated, and the illuminance distribution can be made uniform. Therefore, while ensuring the safety of the entire heat treatment apparatus even when a high voltage is applied to the trigger electrode 31, while improving the uniformity of the heat distribution on the surface of the semiconductor wafer W while efficiently raising the temperature of the semiconductor wafer W, The temperature of the semiconductor wafer W can be raised more efficiently.
[0056]
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.
[0057]
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.
[0058]
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.
[0059]
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.
[0060]
<1.3. Advantages of heat treatment apparatus of this embodiment>
As described above, in the heat treatment apparatus according to the present embodiment, each of the flash lamps 69 and the reflectors 71 is formed by forming the reflectors 71 with insulating ceramics such as aluminum nitride or dialuminum trioxide. Even if the distance is closer than that of the conventional heat treatment apparatus, it is possible to prevent leakage current from flowing from the trigger electrode 31 corresponding to each flash lamp 69 toward the reflector 71. Therefore, even if the distance between the flash lamp 69 and the reflector 71 is reduced as compared with the conventional heat treatment apparatus, the safety of the entire heat treatment apparatus is ensured, and the illuminance distribution on the semiconductor wafer W is compared with the conventional heat treatment apparatus. The temperature of the surface of the semiconductor wafer W can be raised more efficiently while making it uniform.
[0061]
<2. Second Embodiment>
Next, a second embodiment will be described. FIG. 9 is a side sectional view showing a configuration near the light source 105 in the second embodiment of the present invention. As compared to the first embodiment, the hardware configuration of the heat treatment apparatus in the second embodiment is mainly as shown in FIG.
(1) The material of the reflector 171 is different,
(2) the point that the reflector 171 is electrically insulated from the other part of the heat treatment apparatus by the insulator 132;
Is the same as that of the heat treatment apparatus of the first embodiment. Therefore, in the following, this difference will be mainly described.
[0062]
In the following description, the same reference numerals are given to the same components as those in the heat treatment apparatus according to the first embodiment. Since the components with the same reference numerals have already been described in the first embodiment, description thereof will be omitted in the present embodiment.
[0063]
<2.1. Configuration of heat treatment equipment>
Like the reflector 71 of the first embodiment, the reflector 171 is a reflecting plate that reflects light emitted from the plurality of flash lamps 69 and is formed of a conductor such as aluminum or an aluminum-based alloy. As shown in FIG. 9, the reflector 171 is opposite to the semiconductor wafer W held in a horizontal posture above the plurality of flash lamps 69, that is, at a position close to the light transmitting plate 61 across the plurality of flash lamps 69. The plurality of flash lamps 69 are disposed so as to cover the whole.
[0064]
Therefore, a part of the light emitted from the flash lamp 69 passes directly through the light diffusion plate 72 and the light transmission plate 61 and goes into the chamber 65 (see FIG. 1). Further, another part of the light emitted from the flash lamp 69 is once reflected by the reflector 171 and then passes through the light diffusing plate 72 and the light transmitting plate 61 toward the chamber 65 (see FIG. 1). As described above, the reflector 171 can efficiently enter the light emitted from the flash lamp 69 into the chamber 65 and is held in the chamber 65 in the same manner as the reflector 71 of the first embodiment. The temperature of the semiconductor wafer W can be raised efficiently.
[0065]
Further, trigger electrodes 31 corresponding to the respective flash lamps 69 are disposed between the reflector 171 and the respective flash lamps 69. When the flash lamp 69 is caused to emit light, as in the first embodiment, the corresponding flash lamp 69 is caused to emit light by applying a high voltage to each trigger electrode 31.
[0066]
Furthermore, the reflector 171 is fixed in a state where it is supported from a predetermined support portion on the inner upper side of the housing 30 via a plurality of insulators 132 disposed on the reflector 171. The plurality of insulators 132 are formed of an insulating material such as ceramics having an insulating property, and are insertion members that are provided between the inner upper portion of the housing 30 and the reflector 171 as shown in FIG. 9. As described above, since the plurality of insulators 132 are formed of an insulator, the reflector 171 and the other part of the heat treatment apparatus are electrically insulated, and the reflector 171 is electrically connected to the other part of the heat treatment apparatus. And become isolated. In the present embodiment, the plurality of insulators 132 are disposed on the upper portion of the reflector 171. However, the present invention is not limited to this. For example, the plurality of insulators 132 are disposed on the side surface of the reflector 171 and the reflector 171 May be fixed so as to be supported from a predetermined support portion on the inner side wall of the housing 30.
[0067]
Here, consider the case where the reflector 171 is attached to the housing 30 via a member formed of a conductor instead of the insulator 132. In this case, when the distance between the reflector 171 and the flash lamp 69 is reduced, the distance between the trigger electrode 31 corresponding to each flash lamp 69 and the reflector 171 is shortened. For this reason, when a high voltage is applied to the trigger electrode 31, a leak current flows from the trigger electrode 31 toward the reflector 171 and the safety of the entire heat treatment apparatus is reduced.
[0068]
However, the reflector 171 of the present embodiment is fixed to the inner upper portion of the housing 30 via an insulator 132 having an insulating property. Thereby, even if the trigger electrode 31 is brought close to the reflector 171, no potential difference is generated between the reflector 171 and the other part of the heat treatment apparatus. Therefore, no current flows from the reflector 171 toward the other part of the heat treatment apparatus. No leak current flows from 31 toward the reflector 171.
[0069]
Therefore, as in the first embodiment, the semiconductor wafer W can be more efficiently irradiated with light emitted from the plurality of flash lamps 69 while maintaining the safety of the heat treatment apparatus. The temperature of the wafer W can be raised more efficiently.
[0070]
Note that the heat treatment operation of the semiconductor wafer W by the heat treatment apparatus of the present embodiment is performed by the same operation as in the first embodiment.
[0071]
<2.2. Advantages of heat treatment apparatus of this embodiment>
As described above, in the heat treatment apparatus according to the present embodiment, the reflector 171 formed of a conductor such as aluminum or an aluminum alloy is attached to the inner upper portion of the housing 30 via the insulator 132 formed of an insulator. Thus, the reflector 171 and the other part of the heat treatment apparatus can be electrically insulated. Therefore, as in the first embodiment, even if the distance between the reflector 171 and each flash lamp 69 is made closer, no leak current flows from each trigger electrode 31 toward the reflector 171. As a result, the semiconductor wafer W can be efficiently irradiated with light emitted from each flash lamp 69 while maintaining the safety of the heat treatment apparatus, and the illuminance distribution can be made uniform. The temperature of the wafer W can be raised more efficiently.
[0072]
<3. Modification>
While the embodiments of the present invention have been described above, the present invention is not limited to the above examples.
[0073]
In the first embodiment, the reflector 71 itself is formed of an insulating material such as aluminum nitride or alumina to electrically insulate the reflector 71 from the trigger electrode 31. However, the present invention is not limited to this. Instead, for example, an insulating material may be coated on the reflecting surface of a reflector formed of a conductor such as aluminum or an aluminum alloy. Since the trigger electrode and the reflector can be electrically insulated even by adopting such a configuration, even if the distance between the trigger electrode and the reflector is reduced as in the heat treatment apparatus of the first embodiment. The surface of the semiconductor wafer W can be more efficiently heated while ensuring the safety of the entire heat treatment apparatus.
[0074]
【The invention's effect】
According to the invention described in claims 1 to 3, the flash lamp and the reflector are brought closer to each other by electrically insulating the reflector with respect to a trigger portion that applies a high voltage by a predetermined insulating material. However, it is possible to prevent current from leaking from the trigger portion disposed in the vicinity of the flash lamp toward the reflector. Therefore, while maintaining the safety of the heat treatment apparatus, it is possible to improve the irradiation distribution of the flash light while efficiently irradiating the flash light emitted from the flash lamp to the substrate, and to efficiently raise the temperature of the substrate. The uniformity of the heat distribution of the substrate can be improved.
[0075]
In particular, according to the second aspect of the present invention, since the reflector is formed of an insulator, it is possible to prevent current from leaking from the trigger portion to the reflector, so that the flash lamp and the reflector are brought close to each other. Can do.
[0076]
In particular, according to the third aspect of the present invention, since the reflecting plate is formed of insulating ceramics, it is possible to prevent current from leaking from the trigger portion to the reflecting plate, so that the flash lamp and the reflecting plate are brought close to each other. be able to.
[0077]
According to the invention described in claim 4, the reflector is fixed in a state of being supported from a predetermined support portion via the insertion member, so that the reflector and the other part of the heat treatment apparatus Can be electrically isolated. Therefore, it is possible to prevent current from leaking from the trigger portion to the reflecting plate even if the flash lamp and the reflecting plate are brought close to each other.
[0078]
According to the invention described in claim 5, the trigger portion is disposed on the opposite side of the holding means with the flash lamp interposed therebetween. Therefore, the flash light emitted from the flash lamp by the trigger unit can be uniformly irradiated to the substrate without blocking the flash light, and as a result, the substrate surface can be heated uniformly.
[0079]
According to the invention described in claim 6, since the flash light can be uniformly irradiated on the entire surface of the substrate by the plurality of flash lamps, the substrate surface can be heated uniformly.
[Brief description of the drawings]
FIG. 1 is a side sectional view showing a configuration of a heat treatment apparatus of the present invention.
FIG. 2 is a side sectional view showing a configuration of a heat treatment apparatus of the present invention.
FIG. 3 is a side sectional view showing a configuration in the vicinity of a light source in the first embodiment of the present invention.
FIG. 4 is a front view showing a configuration in the vicinity of a flash lamp according to the present invention.
FIG. 5 is a diagram showing a schematic configuration of a light intensity measurement mechanism of the present invention.
FIG. 6 is a block diagram illustrating a configuration of a computer according to the present invention.
FIG. 7 is a view showing an arrangement state of optical fibers with respect to the flash lamp of the present invention.
FIG. 8 is an enlarged view showing a manner of attaching an optical fiber to the reflector of the present invention.
FIG. 9 is a side sectional view showing a configuration near a light source according to a second embodiment of the present invention.
[Explanation of symbols]
5, 105 Light source 10 Computer 11 CPU
16 Display unit 20 Optical fiber 23 Filter 25 CCD
27 CCD control circuit 30 Housing 31 Trigger electrode 39 Internal space 65 Chamber 69 Flash lamps 71 and 171 Reflector 73 Heat diffusion plate 74 Heating plate 132 Insulator W Semiconductor wafer

Claims (6)

In a heat treatment apparatus for heating a substrate by irradiating a flash on the substrate,
(a) holding means for holding the substrate;
(b) a light source having a flash lamp;
(c) a reflector that is disposed on the opposite side of the holding unit with the flash lamp interposed therebetween, and that reflects the flash emitted from the flash lamp;
(d) disposed in the vicinity of the flash lamp, destroys the insulation inside the flash lamp by applying a high voltage, and emits flash light from the flash lamp;
With
A heat treatment apparatus, wherein the reflector is electrically insulated from the trigger portion by a predetermined insulating material. The heat treatment apparatus according to claim 1,
A heat treatment apparatus, wherein the reflector is made of an electrical insulator. The heat treatment apparatus according to claim 2,
The said heat processing apparatus characterized by the said reflecting plate being formed with ceramics. In a heat treatment apparatus for heating a substrate by irradiating a flash on the substrate,
(a) holding means for holding the substrate;
(b) a light source having a flash lamp;
(c) a reflector that is disposed on the opposite side of the holding unit with the flash lamp interposed therebetween, and that reflects the flash emitted from the flash lamp;
(d) an insertion member disposed on the reflecting plate and fixed in a state where the reflecting plate is supported from a predetermined support portion;
(e) a trigger unit that is disposed near the flash lamp, breaks the insulation inside the flash lamp by applying a high voltage, and emits flash light from the flash lamp;
With
The heat treatment apparatus, wherein the reflector is made of a conductor, and the insertion member is made of an electrical insulator. In the heat treatment apparatus according to any one of claims 1 to 4,
The heat treatment apparatus, wherein the trigger portion is disposed between the reflecting plate and the flash lamp. In the heat treatment apparatus according to any one of claims 1 to 5,
The light source has a plurality of flash lamps.

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