JP3986342B2 - Substrate heat treatment equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a heat treatment apparatus for a substrate that improves the characteristics of a substance by irradiating light, and relates to a process for polycrystallizing an amorphous silicon film in manufacturing a thin film transistor (TFT) for a semiconductor substrate and a liquid crystal display device. It is particularly suitable for use in.
[0002]
[Prior art]
For high-resolution displays, small, high-definition active matrix liquid crystal display (LCD) panels using polycrystalline silicon thin film transistors (TFTs) as switching elements have been developed. When a polycrystalline silicon TFT is used as an active element of an LCD, the pixel array unit and the drive array unit can be manufactured on the same transparent insulating substrate in the same process, which has the advantage of reducing processes such as wire bonding and mounting of a drive IC. is there.
[0003]
Polycrystalline silicon TFT is a technique for forming a thin film transistor (TFT) using a semiconductor thin film (thickness of about several tens to several hundreds nm) formed on a substrate having an insulating surface. In particular, when the TFT is a switching element of an LCD, the drive circuit requires a drive frequency of several hundred kHz or more. Therefore, in order to configure the drive circuit, a TFT using a polycrystalline silicon film (polysilicon film) as an active layer is required. Needed.
[0004]
Conventionally, high-temperature annealing has been required to produce a highly crystalline polysilicon film. Such a polysilicon film is generally called high-temperature polysilicon. In order to form a high-temperature polysilicon film, a substrate having high heat resistance that can withstand a process temperature close to 1000 ° C. is necessary. For this reason, a quartz substrate (in some cases, a silicon substrate) is currently used.
[0005]
However, the quartz substrate has a high unit price, and has a problem of an increase in manufacturing cost and an increase in product cost. Therefore, recently, a low-temperature polysilicon film formed on an inexpensive glass substrate has attracted attention. This low-temperature technology reduces the process temperature to 600 ° C or lower, and in this temperature range, an inexpensive, large-area hard glass substrate can be used. LCD can be realized.
[0006]
However, it is not technically easy to produce a high-performance polysilicon TFT in this temperature range, and light is irradiated to an amorphous silicon thin film or an amorphous silicon thin film that has been made amorphous by ion implantation. There is a heat treatment method for polycrystallization. For example, as an insulating film to be a base film on a glass substrate, SiO ₂ A (silicon oxide) film is formed and the SiO ₂ An amorphous silicon film is formed on the film by low pressure CVD (Chemical Vapor Deposition), and the amorphous silicon film is crystallized by a heat treatment process such as laser annealing, solid phase growth, or lamp annealing. Thereby, a polysilicon film is formed.
[0007]
The polysilicon film is doped with a predetermined amount of donors and acceptors to form channel forming regions, drain regions, and the like. Further, a thin film transistor is formed by forming a gate insulating film, a gate electrode, a source electrode, a drain electrode, an interlayer insulating film, and the like, and a semiconductor device including the thin film transistor is manufactured.
[0008]
Furthermore, in the case of a structure in which a crystallized polysilicon film is doped with impurities such as phosphorus and boron, light irradiation treatment is performed for the purpose of activating the impurities implanted in the doping process and modifying the interface of the film. Is done.
[0009]
[Problems to be solved by the invention]
However, the conventional example having such a configuration has the following problems.
In the conventional light irradiation heat treatment method described above, the light source and the large substrate are moved relative to each other in response to the increase in the size of the liquid crystal glass TFT substrate, and the large substrate passes through the light irradiation region by the light source, so that the light irradiation process is performed on the entire surface of the substrate. Japanese Patent Application Laid-Open No. 2001-110738 has been proposed. As a result, there is an advantage that a large substrate can be processed continuously. In addition, a heat treatment apparatus is disclosed in which the substrate is preheated by preheating means before the substrate is heated by the light source. A light source such as a lamp is used as the preheating means used in the heat treatment apparatus described above. On the other hand, it is conceivable that only the silicon film is heated in a short time by irradiating the surface of the substrate with flash light using a flash lamp or the like as the light source.
[0010]
However, when a configuration in which the surface of the substrate is heated using flash light is employed, the flash filament or radiant heat transmitted through the substrate results in the lamp filament of the preheating means being burned or deteriorated. .
[0011]
The present invention has been made in view of such circumstances, and an object thereof is to provide a substrate heat treatment apparatus that can operate stably.
[0012]
[Means for solving the problems and their functions and effects]
In order to achieve the above object, the present invention provides a heat treatment apparatus for heat-treating a substrate by irradiating the substrate with light, and is disposed on the back side of the substrate and irradiates the substrate with light through a condenser. Preheating means for preheating in the light irradiation region generated by the step, and disposed on the surface side of the substrate, and after the substrate is heated to a preheating temperature set in advance, the preheating means is used on the surface of the substrate. Flash heating means for raising the temperature of the preheated substrate to a processing temperature by irradiating the same position as the light irradiation area with flash light through a condenser, and the preheating means and the flash The substrate heat treatment apparatus is characterized in that the heating means is arranged to be inclined in the same direction with respect to the perpendicular in the light irradiation region.
[0013]
The operation of the present invention is as follows. In the substrate heat treatment apparatus according to the first aspect of the present invention, the temperature of the substrate is raised by the preheating step and is heated to the treatment temperature by flash irradiation. This flash does not require so much energy because the glass substrate is preheated. Further, the preheating means and the flash heating means are arranged so as to be inclined in the same direction with respect to the perpendicular in the light irradiation region on the substrate. As a result, the flash heating means prevents most of the flash from reaching the preheating means. Therefore, the preheating means is not deteriorated by the flash.
[0014]
According to a second aspect of the present invention, in the heat treatment apparatus for heat treating the substrate by irradiating the substrate with light, the substrate is disposed on the back side of the substrate, and is generated by light irradiation through the condenser with respect to the substrate. A preheating means for preheating in the light irradiation area; and a light irradiation area by the preheating means on the surface of the substrate after the substrate is heated to a preset preheating temperature, which is disposed on the surface side of the substrate. Flash heating means for raising the temperature of the preheated substrate to a processing temperature by irradiating the same position with a flashlight through a condenser, and a virtual connection between the flash heating means and the light irradiation region The substrate heat treatment apparatus is characterized in that the preheating means is disposed at a position off the line.
[0015]
According to the second aspect of the present invention, the preheating means is disposed at a position off the imaginary line connecting the flash heating means and the light irradiation region. As a result, the flash heating means prevents most of the flash from reaching the preheating means. Therefore, the preheating means is not deteriorated by the flash.
[0016]
According to a third aspect of the present invention, in the substrate heat treatment apparatus according to the first and second aspects, the light irradiation region generated by the preliminary heating unit and the flash heating unit, and the light irradiation region are arranged in the light irradiation region. The substrate is relatively moved.
[0017]
According to the third aspect of the present invention, the entire surface of the substrate is continuously processed, and the preheating unit and the flash heating unit may not be disposed so as to cover the entire surface of the substrate.
[0018]
According to a fourth aspect of the present invention, in the substrate heat treatment apparatus according to any one of the first to third aspects, the light is further detected on the surface side of the substrate on an imaginary line connecting the preliminary heating means and the light irradiation region. One detector and a second detector for detecting light on the back surface side of the substrate on a virtual line connecting the flash heating means and the light irradiation region are provided.
[0019]
According to the fourth aspect of the present invention, the first and second detectors detect light transmitted through the substrate. As a result, it is possible to detect defects such as no light being irradiated from the preheating means and the flash heating means.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described below with reference to the drawings.
<First embodiment>
FIG. 1 is a sectional view of a heat treatment apparatus according to an embodiment of the present invention, and FIG. 2 is a schematic plan view thereof. FIG. 3 is an enlarged view of a main part inside the heat treatment apparatus.
[0021]
This heat treatment apparatus includes a top plate 61, a bottom plate 62, and a pair of side plates 63 and 64, and heat treatment for accommodating and heat-treating a glass substrate W on which an amorphous silicon film is formed as a substrate to be processed. A chamber 65 is provided. Each of the plates 61, 62, 63, 64 constituting the heat treatment chamber 65 is made of, for example, a material such as stainless steel, and the surface thereof is polished so as to prevent deformation by radiant heat during a heat treatment process using flash, which will be described later. Further, in the space constituting the heat treatment chamber 65, a transport means 70 for supporting and transporting a glass substrate W (to be described later) from its lower surface is disposed.
[0022]
In the transfer means 70 in the heat treatment chamber 65, a plurality of transfer rollers 71 are arranged from the vicinity of the opening 66 toward the inside. The transport roller 71 is driven by a drive source (not shown) disposed outside the side plate forming the heat treatment chamber 65 and rotates forward and backward, and transports the glass substrate W thereabove.
[0023]
In addition, an opening 66 for carrying in and out the glass substrate W is formed in the side plate 64 constituting the heat treatment chamber 65. The opening 66 can be opened and closed by a gate valve 68 that rotates about a shaft 67. The glass substrate W is carried into the heat treatment chamber 65 by a transfer robot (not shown) with the opening 66 released.
[0024]
A flash heating unit 80 is disposed above the transfer unit 70 in the heat treatment chamber 65. As shown in the enlarged view of FIG. 3, the flash heating unit 80 includes a bar-shaped xenon flash lamp 81 arranged in parallel with the transport unit 70. A reflector 82 is disposed above the xenon flash lamp 81, and a lens 83 as a condenser is disposed below.
[0025]
The xenon flash lamp 81 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 the outer periphery of the glass tube. Is provided. Since xenon gas is an electrical insulator, electricity does not flow in the glass tube under normal conditions. However, when the insulation is broken by applying a high voltage to the trigger electrode, the electricity stored in the capacitor flows into the glass tube, and the xenon gas is heated by the Joule heat at that time to emit light. In this xenon flash lamp 81, 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.
[0026]
As shown in a side view of FIG. 4, the lens 83 includes a quartz polarizing lens 831 for uniform peripheral exposure and a glass plate 832 made of quartz glass or diffusing glass on the glass substrate W side of the polarizing lens 831. It is installed.
[0027]
The flash light from the xenon flash lamp 81 and the reflected light from the reflector 82 are collected by the lens 83 to generate a strip-shaped light irradiation region M1 on the surface of the glass substrate W located on the conveying means 70. The light irradiation region M1 has an extension in the transport direction F of the glass substrate W around the point P1 where the virtual line L1 connecting the xenon flash lamp 81 and the lens 83 intersects on the surface of the glass substrate W, and the width direction of the glass substrate W It has a strip shape with the same length as (the direction perpendicular to the transport direction). Further, the end of the glass substrate W along the transport direction F collects light from the polarizing lens 831 so that the thermal gradient at the end of the glass substrate W is corrected.
[0028]
An imaginary line L1 connecting the xenon flash lamp 81 and the point P1 of the light irradiation area M1 has an angle α with respect to a perpendicular line L2 on the surface of the glass substrate W opposite to the transport direction F of the glass substrate W, and the xenon flash lamp. 81 is arranged to be inclined. This angle α is preferably set to 45 degrees within a range of 0 <α <90 degrees.
[0029]
A preheating means 90 for preheating the glass substrate W is disposed below the transfer means 70 in the heat treatment chamber 65. In the preheating means 90, one bar-shaped halogen lamp 91 is arranged in parallel with the conveying means 70. In addition, a reflector 92 is disposed in the vicinity of the halogen lamp 91, and a lens 93 is disposed above the lens 93 with the same configuration as the lens 83 serving as a condenser.
[0030]
The halogen lamp 81 is turned on and the reflected light from the reflector 82 is collected by the lens 93 to generate a strip-shaped light irradiation region M 2 on the back surface of the glass substrate W located on the transport means 70. This light irradiation region M2 is equivalent to the light irradiation region M1 on the surface side of the glass substrate W around the point P1 where the virtual line L3 connecting the halogen lamp 91 and the lens 93 intersects on the surface of the glass substrate W. It is set to have a size. As a result, the glass substrate W is irradiated and heated from the front and back surfaces in the same region.
[0031]
An imaginary line L3 connecting the halogen lamp 91 and the point P1 of the light irradiation area M2 has an angle α opposite to the vertical line L2 on the surface of the glass substrate W in the conveyance direction F of the glass substrate W. It is arranged at an angle. This angle α is preferably set to 45 degrees within a range of 0 <α <90 degrees. That is, it is inclined at the same inclination angle in the same direction as the xenon flash lamp 80.
[0032]
Further, on the downstream side in the conveyance direction F of the glass substrate W, the first detector 95 is disposed above the front surface of the glass substrate W, and the second detector 85 is disposed below the back surface of the glass substrate W. The first detection 95 includes a lens 96 and a light receiver 97 that collects light transmitted to the surface side of the glass substrate W on a virtual line L3 connecting the halogen lamp 91 and the light irradiation region M2. The second detector 85 includes a lens 86 and a light receiver 87 that collect light transmitted to the back side of the glass substrate W on a virtual line L1 connecting the xenon flash lamp 81 and the light irradiation region M1. When light is detected by these light receivers 87 and 97, the signal is input to the control unit 100 described later.
[0033]
The loading / unloading position of the glass substrate W shown in FIG. 1 is such that the glass substrate W carried in from the opening 66 is placed on the carrying roller 71 using a carrying robot (not shown) or placed on the carrying roller 71. This is a state for carrying out the glass substrate W taken out from the opening 66.
[0034]
In the heat treatment state of the glass substrate W from the state shown in FIG. 1, the glass substrate W is transferred into the heat treatment chamber 65 by the rotation of the transfer roller 71 in order to perform heat treatment on the glass substrate W. In this transport process, the glass substrate W is heated on the front and back surfaces by the light irradiation regions M1 and M2 set between the transport rollers 71, and the entire surface is irradiated and heated while moving sequentially. When the entire surface of the glass substrate W reaches the downstream side in the transport direction F, the transport roller 71 reverses to return the glass substrate W to the carry-in / out position.
[0035]
An introduction path 75 is formed in the side plate 63 opposite to the opening 66 in the heat treatment chamber 65. The introduction path 75 is for introducing air when the atmosphere is released, which will be described later. Note that nitrogen gas or the like may be introduced instead of introducing air.
[0036]
On the other hand, a discharge path 76 is formed in the bottom plate 62 in the heat treatment chamber 65. The discharge path 76 is connected to a pressure reducing mechanism such as a vacuum pump via an on-off valve 77. The discharge passage 76, the on-off valve 77, and a decompression mechanism (not shown) constitute decompression means according to the present invention.
[0037]
The control unit 100 performs a heat treatment process by the flash heating unit 80 and the preheating unit 90, detection of a lamp state by the first detector 95 and the second detector 85, and the glass substrate W that controls the transport unit 70 and the gate valve 68. The conveying operation and the atmosphere in the heat treatment chamber 65 are controlled by the decompression means.
[0038]
Next, the heat treatment operation of the glass substrate W by the heat treatment apparatus according to the present invention will be described. FIG. 5 is a flowchart showing the heat treatment operation of the glass substrate W by the heat treatment apparatus according to the present invention, and FIG. 6 shows a graph showing the transition of the temperature of the glass substrate W at that time and the conveyance timing of the glass substrate.
[0039]
First, as shown in FIG. 7, a glass plate W1 having a thickness of 0.5 to 1.1 mm (typically 0.7 mm) is prepared as a substrate. The glass plate W1 is generally used for an LCD display device. When the glass plate W1 as described above is prepared, an amorphous silicon film W2 is formed on the glass plate W1 to constitute the glass substrate W.
[0040]
In this heat treatment apparatus, with the gate valve 68 opened, the glass substrate W is loaded through the opening 66 by a transfer robot (not shown) and placed on the transfer roller 71 at the loading / unloading position. When the carry-in of the glass substrate W is completed, the opening 66 is closed by the gate valve 68 (step S1). Thereafter, the conveyance roller 71 starts to rotate at timing T11 in FIG. 6 and moves the glass substrate W in the conveyance direction F.
[0041]
The preheating means 90 is the same as the time when the halogen lamp 91 detects that the first processed portion of the glass substrate W has reached the light irradiation area M2 by the detection means (not shown) at the same time as the operation of the transport roller 71. Lighting is started. For this reason, it preheats from the back surface of the glass substrate W, and as shown in FIG. 6, the temperature of the glass substrate W rises sequentially (step S2).
[0042]
In parallel with the lighting of the preheating means 90, the inside of the heat treatment chamber 65 is depressurized (step S3). That is, by opening the on-off valve 77 and connecting the introduction path 75 to a decompression mechanism (not shown), the heat treatment chamber 65 is evacuated and decompressed. At this time, it is preferable to reduce the pressure in the heat treatment chamber 65 to 1/10 atm to 1/1000 atm in order to effectively exhibit various effects to be described later.
[0043]
When the glass substrate W is transported and the first target region on the surface overlaps the light irradiation region M2, the control unit 100 stops driving the transport roller 71.
[0044]
In this state, the glass substrate W is continuously heated by the preheating means 90. When the temperature of the glass substrate W rises, a temperature sensor (not shown) always monitors whether the surface temperature of the glass substrate W, that is, whether the amorphous silicon film W1 has reached the preheating temperature T1 (step S4). .
[0045]
The preheating temperature T1 is about 200 degrees Celsius to 400 degrees Celsius. Even if the glass substrate W is heated to such a preheating temperature T1, the amorphous silicon film W1 does not become polycrystalline. Further, the glass plate W1 is not warped or distorted.
[0046]
Then, immediately after the surface temperature of the glass substrate W reaches the preheating temperature T1 shown in FIG. 6, the xenon flash lamp 81 is turned on to perform flash heating (step S5). The lighting time of the xenon flash lamp 81 in this flash heating process is about 0.1 to 10 milliseconds, and 10 to 30 J / cm at a wavelength ranging from visible light to infrared. ² The light irradiation region M1 is irradiated in the energy range of. As described above, in the xenon flash lamp 81, the electrostatic energy stored in advance is converted into such a very short light pulse, so that an extremely strong flash light is irradiated.
[0047]
In this state, the surface temperature of the glass substrate W becomes a temperature T2 shown in FIG. The temperature T2 is a temperature necessary for processing the glass substrate W at about 500 degrees Celsius to about 600 degrees Celsius. When the surface of the glass substrate W is heated to such a processing temperature T2, the amorphous silicon film W2 is crystallized to form a polysilicon film. In this state, the amorphous silicon film W2 in the light irradiation region M1 irradiated with light on the glass substrate W is melted by light energy, recrystallized, and changed to a polysilicon film.
[0048]
The light irradiation energy at this time is appropriately adjusted according to the film thickness of the amorphous silicon film W2 to be irradiated. However, since the temperature is raised in advance by the preheating step, it is adjusted within the above-mentioned range.
[0049]
At this time, since the surface temperature of the glass substrate W is raised to the processing temperature T2 in an extremely short time of about 0.1 to 10 milliseconds, the recrystallization of the amorphous silicon film W2 on the glass substrate W is performed. Is completed in a short time. Therefore, it is possible to shorten the processing time and prevent the glass plate W1 from being heated.
[0050]
Further, before the xenon flash lamp 81 is turned on to heat the glass substrate W, the surface temperature of the glass substrate W is heated to the preheating temperature T1 of about 200 degrees Celsius to 400 degrees Celsius using the preheating means 90. Therefore, the glass substrate W can be quickly raised to the processing temperature T2 of about 500 degrees Celsius to 600 degrees Celsius by the xenon flash lamp 81.
[0051]
In this flash heating process, each of the plates 61, 62, 63, 64 constituting the heat treatment chamber 65 receives a light beam that has not been absorbed by the amorphous silicon film W2. However, since the plates 61, 62, 63 and 64 are made of surface-polished aluminum, the plates 61, 62, 63 and 64 are not deformed by heat.
[0052]
The flash heating process described above is performed under reduced pressure. For this reason, the gas does not react in the heat treatment chamber 65 and the particles are not diffused or the glass substrate W is not moved as in the prior art.
[0053]
Similarly, by reducing the pressure of the heat treatment chamber 65, the entire surface of the glass substrate W can be uniformly heated in the preheating step and the flash heating step without causing convection in the heat treatment chamber 65.
[0054]
Similarly, since the xenon flash lamp 81 and the halogen lamp 91 are arranged to be inclined at an angle α, when the respective irradiation light travels along the imaginary lines L1 and L3, the irradiation light is transmitted to each other even though the glass substrate W is transmitted. Is not directly exposed to. As a result, it is possible to prevent the components such as filaments constituting each lamp from being deteriorated by irradiation light or radiant heat. In particular, since the halogen lamp 91 is not directly exposed to the strong flash of the xenon flash lamp 81, it can be used with a longer lifetime.
[0055]
Furthermore, by reducing the pressure inside the heat treatment chamber 64, oxygen and organic substances can be excluded from the heat treatment chamber 65. For this reason, it becomes possible to prevent the lifetime of the heat treatment apparatus from being reduced due to the oxidation of the material constituting the heat treatment chamber 65 or the blackening of the organic matter.
[0056]
When the heat treatment of the first heat treatment part is completed, the step conveyance S6 in which the conveyance roller 71 is driven again from the timing T12 and the second heat treatment part is conveyed is performed again. The transport distance of the step transport S6 is set to a length in the transport direction F equivalent to the light irradiation region M1 or a slightly shorter distance. By doing so, it is possible to perform the process by sequentially moving the heat treatment sites in the same range as the light irradiation region M1 over the entire surface of the glass substrate W without any gap.
[0057]
Then, unless the rear end of the glass substrate W passes through the light irradiation region M1, the process returns to step S4 in step S7, and the heat treatment from the preheating by the light irradiation heating to the flash heating is performed similarly to the first heat treatment portion. . Preheating by the preheating means 90 is continued during the step conveyance S6, and flash heating S5 is performed when the preheating temperature T1 is reached. By repeating this operation, the entire surface of the glass substrate W is heat-treated.
[0058]
During the heat treatment process from step S4 to step S7 of the glass substrate W, the first detector 95 and the second detector 85 always detect the irradiation light. Each transmits a detection signal from the light receiver 97 and the light receiver 87 to the control unit 100. By doing so, the control unit 100 monitors whether the xenon flash lamp 81 and the halogen lamp 91 are lit at a timing according to a preset program. When the control unit 100 does not receive a signal from the light receivers 87 and 97 at the timing when each lamp is lit, in order to prevent processing defects of the glass substrate W, for example, the heat treatment apparatus is stopped or an abnormality is detected on the operation panel. It is possible to configure such as displaying on the screen. According to this configuration, abnormality of the lamp is confirmed during the light irradiation heat treatment, so that it is possible to cope with an abnormality more quickly.
[0059]
In addition, since the detection of the light by the 1st detector 95 and the 2nd detector 85 is performed during the optical heat processing process, since the light which permeate | transmits the glass substrate W is detected, the signal by the light receivers 87 and 97 is used. Since the level becomes smaller, it is necessary to set the setting level in the determination flow by the control unit 100 to a value obtained in advance through experiments or the like.
[0060]
When it is detected that the rear end of the glass substrate W has passed through the light irradiation region M <b> 1, the heat treatment chamber 65 is closed by closing the on-off valve 77 and introducing air from the introduction path 76. The atmosphere is released (step S8). Then, the halogen lamp 91 of the preheating means 90 is turned off (step S9). Further, the control unit 100 reverses the transport roller 71 at the timing T110 to transport the glass substrate W to the unloading position and stop.
[0061]
The reason why the flash heating is performed immediately after the surface temperature of the glass substrate W reaches the preheating temperature T1 is as follows. In the heat treatment apparatus according to the present invention, the flash heating is performed at a temperature higher than the preheating temperature T1 by performing flash heating immediately after the surface temperature of the glass substrate W reaches the preheating temperature T1. Prevent it from being executed at some point.
[0062]
At the same time, after the heating process for the entire surface of the glass substrate W is completed, the temperature inside the heat treatment chamber 65 is lowered by releasing the atmosphere inside the heat treatment chamber 65 to the atmosphere.
[0063]
When the air release of the heat treatment chamber 65 is completed, the opening 66 closed by the gate valve 68 is released. And the glass substrate W mounted on the conveyance roller 71 is carried out by the conveyance robot which is not shown in figure (step S8).
[0064]
As described above, a high-quality polycrystalline silicon film can be obtained by the heat treatment according to the present invention, and as a result, a TFT having excellent characteristics can be obtained. In addition, the apparatus can be miniaturized and the life of components can be improved. As a result, for example, a liquid crystal display (LCD) panel using TFT can be manufactured at low cost.
[0065]
Next, a maintenance process in this heat treatment apparatus will be described.
In the flash heating means 80 and the preheating means 90, the first detector 95 and the second detector 85 are arranged in the respective light irradiation directions. Individual lighting of the xenon flash lamp 81 and the halogen lamp 91 is set by an operation unit (not shown) and the lighting control is performed by the control unit 100 in a state where the glass substrate W is not loaded. Signals detected by the light receivers 87 and 97 for light irradiation due to this lighting are input to the control unit 100. And a lighting state is judged by ON / OFF or strength of this signal.
[0066]
That is, when the xenon flash lamp 81 is abnormal and does not light up, no light is received by the light receiver 87 via the lens 86, so that no signal is output from the second detector 85. As a result, an abnormality of the xenon flash lamp 81 is displayed on the operation unit to prompt the operator to perform maintenance.
[0067]
By doing so, the lighting failure of the xenon flash lamp 81 can be confirmed in the sealed heat treatment chamber 65. Moreover, even when the lighting state is weak, it can be detected by collecting light at a site where the light irradiation intensity is strongest. Further, even if there is reflected light in the heat treatment chamber 65, it has less influence on the collected detection light and can be detected more accurately.
[0068]
Similarly, in the case of the first detector 95 corresponding to the halogen lamp 91, the preheating means 90 can accurately detect the lighting state of the halogen lamp 91.
[0069]
Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 8 is an enlarged view of the main part inside the heat treatment apparatus.
That is, the preheating unit 80 and the preheating unit 90 are not disposed so as to be inclined in the same direction with respect to the perpendicular line L2 in the light irradiation region M1, but the preheating unit is disposed at a position away from the virtual line L1 of the flash heating unit 90. By arranging 90, it may be configured not to be directly exposed to each other's irradiation light. In the case of this configuration, since the second detector 95 can be disposed close to the flash heating means 80 on the surface side of the glass substrate W, the arrangement position is opposite to the direction in which the irradiation light from the flash heating means 80 travels. The influence of light from the flash heating means 80 on the second detector 95 can be reduced. Similarly, on the back surface side of the glass substrate W, the first detector 85 can be disposed at a site where the influence from the preheating means 90 is small.
[0070]
In addition, this invention is not limited to the Example mentioned above, It can implement also with another form as follows.
[0071]
(1) In the above embodiment, the amorphous silicon film is polycrystallized. However, as the glass substrate having the silicon film formed on the surface, the glass substrate having the amorphous silicon film is formed. In addition, the heat treatment method of the present invention is applied to a glass substrate on which various silicon films are formed such as a glass substrate on which a silicon nitride film is formed or a glass substrate on which a polycrystalline silicon film is formed. Can be implemented. For example, an amorphous silicon film made amorphous by ion implantation of silicon into a polycrystalline silicon film formed by a CVD method is formed, and a silicon oxide film serving as an antireflection film is further formed thereon. In this state, the present invention is also applicable to the case where a polycrystalline silicon film in which the amorphous silicon film is polycrystallized is formed by irradiating light on the entire surface of the amorphous silicon film and performing the heat treatment according to the present invention.
[0072]
(2) The underlying SiO on the glass substrate ₂ A TFT substrate having a film, a polysilicon film obtained by crystallizing amorphous silicon, and a structure in which an impurity such as phosphorus or boron is doped in the polysilicon film may be heat-treated according to the present invention. The purpose of such light irradiation treatment is mainly to activate the impurities implanted in the doping process and to modify the film. In this process, a uniform process can be performed.
[0073]
In addition, various design changes can be made within the scope of technical matters described in the claims.
[0074]
【The invention's effect】
According to the present invention, after a large substrate is preheated by light irradiation and then flash-heated, the film can be uniformly heat-treated by light irradiation. At this time, since the preheating means and the flash heating means are not exposed to the irradiation light, it is possible to prevent deterioration of the parts.
[Brief description of the drawings]
FIG. 1 is a side sectional view of a heat treatment apparatus according to the present invention.
FIG. 2 is a plan view of a heat treatment apparatus according to the present invention.
FIG. 3 is an enlarged view of a main part of the heat treatment apparatus according to the present invention.
4 is an explanatory view showing a configuration of a flash heating means 80. FIG.
FIG. 5 is a flowchart showing a heat treatment operation of the glass substrate W by the heat treatment apparatus according to the present invention.
FIG. 6 is a graph showing the transition of the processing temperature of the glass substrate W and the conveyance timing.
7 is a cross-sectional view showing a glass substrate W. FIG.
FIG. 8 is an enlarged view of a main part showing a second embodiment of the heat treatment apparatus according to the present invention.
[Explanation of symbols]
61 Upper plate
62 Bottom plate
63, 64 side plate
65 Heat treatment room
66 opening
68 Gate valve
80 Flash heating means
81 Xenon flash lamp
85 Second detector
90 Preheating means
91 Halogen lamp
95 First detector
100 Control unit
70 Conveying means
71 Transport roller
M1, M2 Light irradiation area
L1, L3 virtual line
L2 perpendicular
H Overshoot
T1 Preheating temperature
T2 processing temperature
W glass substrate
W1 glass plate
W2 amorphous silicon film

Claims (4)

In a heat treatment apparatus for heat treating a substrate by irradiating the substrate with light,
Preheating means disposed on the back side of the substrate and preheating the light irradiation region generated by light irradiation through the condenser with respect to the substrate;
The substrate is disposed on the surface side of the substrate, and after the substrate has been heated to a preset preheating temperature, the surface of the substrate is flashed via a condenser with respect to the same position as the light irradiation region by the preheating means. Flash heating means for raising the temperature of the preheated substrate to a processing temperature by irradiating with,
With
The substrate heat treatment apparatus, wherein the preheating means and the flash heating means are arranged in the same direction with respect to a perpendicular in the light irradiation region. In a heat treatment apparatus for heat treating a substrate by irradiating the substrate with light,
Preheating means disposed on the back side of the substrate and preheating the light irradiation region generated by light irradiation through the condenser with respect to the substrate;
The substrate is disposed on the surface side of the substrate, and after the substrate has been heated to a preset preheating temperature, the surface of the substrate is flashed via a condenser with respect to the same position as the light irradiation region by the preheating means. Flash heating means for raising the temperature of the preheated substrate to a processing temperature by irradiating with,
With
An apparatus for heat-treating a substrate, wherein the preliminary heating means is disposed at a position deviated from an imaginary line connecting the flash heating means and the light irradiation region. In the heat processing apparatus for a substrate according to claim 1 or 2,
A substrate heat treatment apparatus, wherein a light irradiation region generated by the preliminary heating unit and the flash heating unit and the substrate disposed in the light irradiation region move relatively. 4. The substrate heat treatment apparatus according to claim 1, further comprising: a first detector that detects light on a surface side of the substrate on an imaginary line connecting the preliminary heating unit and a light irradiation region; and the flash heating. A substrate heat treatment apparatus, comprising: a second detector for detecting light on a back surface side of the substrate on a virtual line connecting the means and the light irradiation region.

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