JP2003133248A - Method for heat-treating substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method that does not need thermocouples or the like, by which a substrate can be heated in an ordinary or cold region without causing any problem and temperature control can be accurately performed based on detected a value of a radiation thermometer. SOLUTION: This method comprises a constant power heating step for heating the substrate by supplying constant power to a light source for heating and a control heating step for heating the substrate by controlling a power supply to the light source for heating based on the detected value of the radiation thermometer, and when the detected value of the radiation thermometer reaches a preset control starting temperature, the constant power heating step is shifted to the control heating step.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a semiconductor wafer, a glass substrate for a liquid display device, a glass substrate for a photomask, a substrate for an optical disk, etc., which are brought into a heat treatment furnace one by one and heated by light irradiation. The present invention relates to a heat treatment method for a substrate to be heat treated.

[0002]

2. Description of the Related Art In a semiconductor device manufacturing process,
A thermal oxide film is formed on the surface of a wafer by heating the wafer by radiating the substrates, for example, silicon wafers into a heat treatment furnace one by one and irradiating the substrates with light, as in a lamp annealing device or CVD. 2. Description of the Related Art A single-wafer type heat treatment apparatus that performs thermal diffusion of impurity atoms to form a pn junction and various annealing treatments is widely used in various processes. FIG. 5 shows an example of the configuration of a lamp annealing device which is one of the heat treatment devices.

The lamp annealing apparatus whose schematic side sectional view is shown in FIG. 5 includes a heat treatment furnace 10 having an opening 12 for loading and unloading a silicon wafer W. The upper furnace wall of the heat treatment furnace 10 is made of a material having infrared transparency,
The light incident window 14 is formed of, for example, quartz glass. The opening 12 of the heat treatment furnace 10 has a gate valve 1
It is closed by 6 for opening and closing. Although not shown, on the side of the surface of the heat treatment furnace 10 that faces the opening 12, the wafer W is horizontally supported by a support arm, and the wafer W before heat treatment is loaded into the heat treatment furnace 10 and subjected to the heat treatment. A wafer loading / unloading device for unloading the wafer W from the heat treatment furnace 10 is provided.

A wafer support ring 18 made of SiC or the like is disposed inside the heat treatment furnace 10, and the wafer support ring 18 is rotatably held in a horizontal posture by a wafer holding / rotating mechanism 20. There is. Wafer W
Are horizontally supported on the wafer support ring 18.
Further, there is provided a wafer transfer mechanism 24 that has a plurality of, for example, three support pins 22 that abut the lower surface of the wafer W to support the wafer W and that reciprocates in the vertical direction.

A lamp house 26 is provided above the heat treatment furnace 10 so as to face the light incident window 14. In the lamp house 26, a plurality of lamps 28 such as halogen lamps and arc lamps are arranged in a line on the same plane, and a reflector 30 is arranged for each lamp 28. The infrared light emitted from each lamp 28 is efficiently condensed by the reflector 30, passes through the light irradiation window 14, and is irradiated into the heat treatment furnace 10. The infrared light with which the heat treatment furnace 10 is irradiated is absorbed by the surface of the wafer W, and the wafer W is heated by this energy.

Inside the heat treatment furnace 10, facing the upper surface of the wafer W supported on the wafer support ring 18, a plurality of gas blowing holes formed of a material having infrared transparency, for example, quartz glass. A gas flow distribution plate 32 having holes 34 formed therein is disposed. This gas flow distribution plate 3
A gas introducing chamber 36 into which a processing gas such as nitrogen is introduced is provided between the light incident window 2 and the light incident window 14, and the gas introducing chamber 36 is
It is connected to the processing gas supply source through a gas introduction path (not shown). On the other hand, an annular gas exhaust passage 38 is formed between the wafer holding / rotating mechanism 20 and the inner peripheral wall surface of the heat treatment furnace 10, and the gas exhaust passage 38 is connected to an exhaust port (not shown) for communication. Further, in order to keep the airtightness inside the heat treatment furnace 10 high, O-rings 40 are attached to the contact portion with the gate valve 16 and the joint portion with the light incident window 14, respectively.

A plurality of temperature detectors are provided at the bottom of the heat treatment furnace 10 so as to face the lower surface of the wafer W supported on the wafer support ring 18 and the lower surface side of the wafer support ring 18.
For example, radiation thermometers 42a, 42b, 42c, 42d are installed. These radiation thermometers 42a, 42b, 4
Infrared rays radiated from the back surface of the wafer W are made incident by 2c and 42d, and the temperature of the wafer W at a plurality of positions and the temperature of the wafer support ring 18 are measured in a non-contact manner during the heat treatment. In addition, inside the heat treatment furnace 10,
During the heat treatment of the wafer W, the radiation thermometers 42a, 42b, 42
A light blocking ring 44 for blocking stray light of the lamp 28 is provided so that infrared light from the lamp 28 does not enter the c and 42d. The light shield ring 44 is formed of SiC or the like in a ring shape.

FIG. 6 is a block diagram showing a schematic structure of a temperature control system of the lamp annealing apparatus. When the wafer W is heated by the infrared light emitted from the lamp 28, the temperature of the wafer W is detected by the radiation thermometer 42. The detection signal of the radiation thermometer 42 is sent to the control device 46, and the control device 46 compares the detected temperature of the wafer W with the target temperature, and calculates the electric power supplied to the lamp 28 based on the deviation. . Then, feedback control is performed such that the controller 46 issues an instruction to the power unit 48, power is supplied from the power unit 48 to the lamp 28 according to the instruction, and the light amount of the lamp 28 is adjusted.

The temperature measurement of the wafer W by the radiation thermometer 42 will be described with reference to FIG. FIG. 7 shows the relationship between the actual temperature of the wafer W (actual temperature) and the temperature detected by the radiation thermometer 42 (detected temperature) when the wafer W is heated by supplying constant power to the lamp 28. FIG. 6 is a response waveform diagram showing In this figure, a curve a shown by a solid line represents a change in the detected temperature, and a curve b shown by a broken line represents a change in the actual temperature.

Immediately after the lamp 28 is turned on and heating of the wafer W is started, the detected temperature shows a high value, which is far from the actual temperature. This is because the light from the lamp 28 passes through the silicon wafer W. That is, the silicon wafer has a property of transmitting light in a low temperature region, and the lamp 2 is cooled when the wafer W is cold.
When 8 is turned on, the transmitted light of the wafer W is incident on the radiation thermometer 42 at that moment. As a result, the light energy is converted into temperature and the detected temperature is estimated to be high. After that, the detected temperature shows peak p (peak p
Indicates that the transmitted light of the wafer W is maximized.) Since the light transmittance of the wafer W decreases as the actual temperature of the wafer W increases, the detected temperature temporarily decreases. And
When the detected temperature and the actual temperature gradually approach each other and the detected temperature starts to rise again, the detected temperature and the actual temperature eventually match. S in the figure indicates a state in which the detected temperature and the actual temperature match, and accurate temperature control is possible from this point. The above is a description of the general response characteristics of the radiation thermometer 42. The line 1 shown by the thin broken line in FIG.
The output lower limit temperature of the radiation thermometer 42 is shown.

[0011]

In the lamp annealing apparatus, the heating of the wafer is started at a room temperature. However, as described above, the temperature of the wafer cannot be accurately measured by the radiation thermometer in the normal temperature to low temperature region. For this reason, if feedback control is attempted from the start of heating the wafer, the control is performed based on the detected temperature higher than the actual temperature of the wafer in the normal temperature or low temperature region, so that the actual temperature of the wafer and the detected temperature match. It will take a long time before accurate temperature control can be performed. Therefore, in order to perform accurate temperature control from the start of heating the wafer, it is necessary to install a thermocouple in addition to the radiation thermometer to measure the temperature in the low temperature region. However, when a thermocouple or the like is provided side by side, there is a problem that the device configuration, the control system, etc. become complicated.

The present invention has been made in view of the above circumstances, and can heat a substrate in a normal temperature to a low temperature region without any trouble without providing a thermocouple or the like, and a radiation thermometer. It is an object of the present invention to provide a substrate heat treatment method capable of performing accurate temperature control based on a detection value obtained by.

[0013]

The invention according to claim 1 is
The substrate is heated by irradiating the substrate with light from the heating light source, the temperature of the substrate is detected by the radiation thermometer, and the power supplied to the heating light source is controlled based on the detection value of the radiation thermometer. In a heat treatment method for heating a substrate from room temperature according to a predetermined sequence, a constant power heating step of heating the substrate by supplying constant power to the heating light source, and the heating based on a detection value by the radiation thermometer. Control heating step of heating the substrate by controlling the power supplied to the light source for use, the control from the constant power heating step when the detection value by the radiation thermometer reaches a preset control start temperature It is characterized by shifting to a heating process.

According to a second aspect of the present invention, in the heat treatment method according to the first aspect, the constant power heating step is performed on the heating light source from the time when the heating of the substrate is started to the time when a preset time elapses. A timed heating period in which a constant power is supplied to heat the substrate, and a temperature at which a constant power is supplied to the heating light source to heat the substrate until the detection value of the radiation thermometer reaches the control start temperature. And a heating period for detection.

According to a third aspect of the present invention, in the heat treatment method according to the first aspect, the constant power heating step is performed on the heating light source from the time when the heating of the substrate is started to the time when a preset time elapses. The previous heating period in which a constant power is supplied to heat the substrate, and the detection value by the radiation thermometer,
An intermediate heating period in which a constant power is supplied to the heating light source to heat the substrate until the temperature is lower than the preset transition temperature which is a temperature lower than the control start temperature, and the detection value by the radiation thermometer is the It is characterized by comprising a second-stage heating period in which a constant power is supplied to the heating light source to heat the substrate until the control start temperature is reached.

According to a fourth aspect of the present invention, in the heat treatment method according to the first aspect, the constant power heating step is a first step in which the detection value by the radiation thermometer is preset from the time when the heating of the substrate is started. The heating temperature of the substrate by supplying constant power to the heating light source until the temperature reaches the transition temperature, and the detected value by the radiation thermometer is higher than the control start temperature and the first transition temperature. An intermediate heating period in which a constant power is supplied to the heating light source to heat the substrate until the temperature is lower than the preset second transition temperature, and the detection value by the radiation thermometer is controlled by the control. It is characterized by comprising a post-heating period in which a constant power is supplied to the heating light source to heat the substrate until the start temperature is reached.

According to the substrate heat treatment method of the first aspect of the present invention, in the constant power heating step, constant power is supplied to the heating light source to heat the substrate. Therefore, since the temperature control is not performed in the low temperature region after the heating of the substrate is started at room temperature, the influence of the difference between the detection value of the radiation thermometer and the actual temperature of the substrate does not appear. When the detection value of the radiation thermometer reaches the preset control start temperature, the constant power heating process shifts to the control heating process, and the power supplied to the heating light source is controlled based on the detection value of the radiation thermometer. Then, the substrate is heated. At the time of this transition,
Since the actual temperature of the substrate and the detected temperature match, accurate temperature control is performed.

In the heat treatment method of the invention according to claim 2, in the constant power heating step, a constant power is applied to the heating light source from the time when the heating of the substrate is started to the time when a preset time elapses (timed heating period). Is supplied to heat the substrate. During this period, it is not detected whether the detected value by the radiation thermometer has reached the control start temperature.Therefore, by setting the timed heating period appropriately, the actual temperature of the substrate and the detected temperature can be Even if the detection value of the radiation thermometer reaches the control start temperature before the coincidence, the constant power heating process is not shifted to the control heating process at that time. Then, when the temperature detection heating period is entered after the timed heating period, it is detected whether or not the detection value by the radiation thermometer has reached the control start temperature, and when the detected value reaches the control start temperature, constant power heating is performed. The process shifts to the controlled heating process.

In the heat treatment method of the invention according to claim 3, in the constant power heating step, a constant power is supplied to the heating light source from the time when the heating of the substrate is started to the time when a preset time elapses (pre-stage heating period). Is supplied to heat the substrate. During this period, it is not detected whether the detected value by the radiation thermometer has reached the control start temperature.Therefore, by setting the previous heating period appropriately, the actual temperature of the substrate and the detected temperature can be Even if the detection value of the radiation thermometer reaches the control start temperature before the coincidence, the constant power heating process is not shifted to the control heating process at that time. After the previous heating period, constant power is supplied to the heating light source until the value detected by the radiation thermometer is lower than the control start temperature and lower than the preset transition temperature (intermediate heating period). Since the substrate is heated, the detected value by the radiation thermometer is controlled when the actual temperature of the substrate and the detected temperature do not match at the time when the previous heating period in the process of the detected value by the radiation thermometer decreasing. Even above the starting temperature, at that point,
There is no transition from the constant power heating process to the controlled heating process. Then, when the detection value of the radiation thermometer falls below the transition temperature and enters the second heating period, it is detected whether the detection value of the radiation thermometer reaches the control start temperature, and the detection value reaches the control start temperature. Then, the constant power heating step shifts to the controlled heating step.

In the heat treatment method of the invention according to claim 4, in the constant power heating step, from the time when the heating of the substrate is started to the time when the value detected by the radiation thermometer reaches the first transition temperature (previous heating period). A constant power is supplied to the heating light source to heat the substrate. During this period, it is detected whether the detected value by the radiation thermometer has reached the first transition temperature, and when the detected value reaches the first transition temperature, the intermediate heating step is started. Therefore, even if the detection value by the radiation thermometer reaches the control start temperature during the previous heating period, the constant power heating process is not switched to the control heating process at that time. When entering the intermediate heating step, until the values detected by the radiation thermometer are lower than the control start temperature and the first transition temperature and lower than the preset second transition temperature (intermediate heating period), A constant power is supplied to the heating light source to heat the substrate. Therefore, when the previous heating period elapses in the process of decreasing the radiation thermometer detection value, the radiation thermometer detection value exceeds the control start temperature when the actual temperature of the substrate does not match the detection temperature. However, at that time, the transition from the constant power heating step to the controlled heating step is not performed. Then, when the detection value by the radiation thermometer falls below the second transition temperature and enters the second heating period, it is detected whether or not the detection value by the radiation thermometer has reached the control start temperature, and the detection value starts control. When the temperature is reached, the constant power heating process shifts to the controlled heating process.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below with reference to the drawings.

The substrate heat treatment method according to the present invention is carried out using a lamp annealing apparatus as shown in FIGS. 5 and 6, for example. The device configuration and the control system of the lamp annealing device have been described above, and thus the description thereof is omitted here.

FIG. 1 shows a first embodiment of the present invention, in which the actual temperature of the wafer W and the detected value by the radiation thermometer 42 when the electric power is supplied to the lamp 28 to heat the wafer W. It is a response waveform diagram showing the relationship of. In this figure, the curve A1 shown by the solid line represents the change in the detected temperature, and the curve B shown by the broken line represents the change in the actual temperature.

In the method according to the first embodiment, the wafer W
Started heating from room temperature, up to the point where the detected value by the radiation thermometer 42 reaches a preset control start temperature t _u (constant power heating step), the heating of the wafer W by supplying a constant power to the lamp 28 To do. Then, when the detected temperature reaches the control start temperature _tu and the detected temperature and the actual temperature of the wafer W match (point S), the constant power heating step is shifted to the control heating step. After that, as described above, the radiation thermometer 42
The wafer W is heated by feedback-controlling the electric power supplied to the lamp 28 based on the detection value obtained by.

According to such a heat treatment method, the temperature of the wafer W is not controlled based on the value detected by the radiation thermometer 42 in the normal temperature or low temperature region. And the actual temperature of the wafer W is not affected. At the time of transition from the constant power heating process to the controlled heating process, the wafer W
Since the actual temperature of 1 and the detected temperature match, accurate temperature control is performed.

Next, FIG. 2 shows a second embodiment of the present invention and is a response waveform diagram similar to that of FIG. In this figure, a curve A2 shown by a solid line represents a change in the detected temperature, and a curve B shown by a broken line represents a change in the actual temperature.

In the method according to the first embodiment described above, when the peak value of the transmitted light of the wafer W is sufficiently large, etc., the curve A representing the change in the detected temperature is shown by the chain double-dashed line in FIG.
As indicated 2, the values detected by the radiation thermometers 42 in the constant power heating step would once reached the control start temperature t _u (Q point), yet the detected temperature and the wafer W at that time
Despite the fact that the actual temperature does not match, the constant power heating process shifts to the controlled heating process. However, at this point in time, the detected temperature and the actual temperature do not match, which causes a problem that accurate temperature control cannot be performed. The method according to the second embodiment is for solving such a problem.

In the method according to the second embodiment, the constant power heating step is divided into two periods, a timed heating period and a temperature detection heating period. Then, in the timed heating period, constant power is supplied to the lamp 28 to heat the wafer W from the time when the heating of the wafer W is started to the time when a preset time elapses. Beyond timed heating period enters the temperature sensing heating period, the temperature detecting heating period, the heating of the wafer W by supplying a constant power to the lamp 28 to the point where the detected value with a radiation thermometer reaches the control start temperature t _u To do. In the timed heating period, the time when the waveform of the detection value by the radiation thermometer 42 shows a peak and then falls and becomes lower than the control start temperature _tu is obtained by experiments under various conditions,
Make an appropriate decision based on it.

According to such a heat treatment method, the radiation thermometer 4 is used during the timed heating period in the constant power heating step.
Whether the detection value by 2 reaches the control start temperature t _u detection is not performed. Therefore, even if the value detected by the previously radiation thermometer 42 and the actual temperature and the detected temperature of the wafer W coincide with once reached the control start temperature t _u,
At that point, the transition from the constant power heating step to the controlled heating step is not performed. Then, when the temperature detection heating period is entered after the timed heating period, it is detected whether the detection value by the radiation thermometer 42 has reached the control start temperature _tu , and the detected temperature reaches the control start temperature _tu . At that time, the constant power heating step is shifted to the controlled heating step.

Next, FIG. 3 shows a third embodiment of the present invention and is a response waveform diagram similar to FIGS. 1 and 2. In this figure, the curve A3 shown by the solid line represents the change in the detected temperature, and the curve B shown by the broken line represents the change in the actual temperature.

In the method according to the second embodiment described above, the curve A3 representing the change in the detected temperature is shown by the chain double-dashed line in FIG.
As showed, when the timed heating period has elapsed in the course of the detection value by the radiation thermometer 42 is lowered, if the detected temperature is equal to the control starting temperature t _u it from higher (point R), at which point the Even though the detected temperature and the actual temperature of the wafer W do not match yet, the constant power heating step is shifted to the control heating step. However, since the detected temperature and the actual temperature do not match at this point,
This causes a problem that accurate temperature control cannot be performed. Also, since the optimum timed heating period changes depending on the type of wafer and the heat condition of the heat treatment furnace, it is necessary to frequently readjust the timed heating period.
It's very troublesome. On the other hand, when the readjustment of the timed heating period is neglected, the timed heating period is too short and the same problem as the method according to the first embodiment described above occurs, or the timed heating period is too long, The timing to start the temperature control may be delayed. The method according to the third embodiment is for solving the above problems.

In the method according to the third embodiment, the constant power heating step is divided into three periods of a pre-heating period, an intermediate heating period and a post-heating period. Then, in the pre-stage heating period, constant power is supplied to the lamp 28 to heat the wafer W from the time when the heating of the wafer W is started to the time when a preset time elapses. A peak of the waveform due to the transmitted light of the wafer W appears in the value detected by the radiation thermometer 42, and after the previous heating period, the intermediate heating period starts. The pre-heating period is determined so that the time point at which the peak of the waveform due to the transmitted light of the wafer W appears at the detected temperature is the end point. Wafer W
Since the time from the start of heating the temperature until the peak of the waveform due to the transmitted light appears at the detected temperature is almost constant regardless of the situation, once the previous heating period is adjusted, it is necessary to readjust it. There is no particular.

In the intermediate heating period, when the value detected by the radiation thermometer 42 is lower than the control start temperature t _u and lower than the preset transition temperature t _d (t _d <t _u ) (point R). Until then, a constant electric power is supplied to the lamp 28 to heat the wafer W. Since the transmitted light of the wafer W decreases as the actual temperature of the wafer W increases, the detected temperature decreases, and when the detected temperature falls below the transition temperature t _d , the latter heating period starts. The subsequent heating period, to the point where the detected value with a radiation thermometer reaches the control start temperature t _u, for heating the wafer W by supplying a constant power continues to lamp 28. Incidentally, transition temperature t _d needs to be set to always lower temperature than the control start temperature t _u. If transition temperature t
_{when d} is set higher than the control start temperature t _u is the moment when moved from the intermediate heating period to a subsequent heating period, the transition condition (detected temperature ≧ control to control the heating process from the subsequent heating period of constant power heating step The starting temperature t _u ) is satisfied, and the temperature control is immediately started. As a result, the temperature control starts while the detected temperature and the actual temperature of the wafer W do not match.

When the wafer W is heated and the actual temperature of the wafer W further rises in the latter heating period, the detected temperature starts to show a value close to the actual temperature, and the detected temperature also starts to rise.
Then, when the detected temperature further approaches the actual temperature, the detected temperature reaches the control start temperature _tu , and the detected temperature and the actual temperature of the wafer W match (point S), the constant power heating process shifts to the control heating process. To do. In the controlled heating step, the power supplied to the lamp 28 is feedback-controlled on the basis of the value detected by the radiation thermometer 42 to heat the wafer W.

According to such a heat treatment method, in the constant power heating step, the intermediate heating period starts after the previous heating period, and the wafer W is kept at a constant power until the detected temperature falls below the transition temperature t _d in the intermediate heating period. since the heating is carried out, upon elapse of the preceding heating period in the process value detected by the radiation thermometer 42 is lowered, even if the detected temperature is not higher than the control start temperature t _u, at that time, the constant power heating step There is no transition to the controlled heating process. Therefore,
As in the case of the method according to the second embodiment, in the state where the actual temperature of the wafer W and the detected temperature do not match, the pre-heating period (in the timed heating period in the method according to the second embodiment, It does not happen that the controlled heating process is started immediately after (equivalent). Then, after the intermediate heating period and the subsequent heating period, the radiation thermometer 42 detects whether or not the detection value has reached the control start temperature t _u , and the detected temperature has reached the control start temperature t _u . At this point, the constant power heating process is transferred to the controlled heating process.

FIGS. 4A and 4B show the third embodiment.
3 shows changes in the detected temperature when the method according to the embodiment is performed.
It is a figure. (A) shows the temperature change at the start of work, for example.
(B) shows the temperature change during steady operation, for example.
Shows. As you can see from these figures,
(A) due to differences in yield and heat treatment furnace temperature
In the curves (1) and (b), heating of the wafer W is started.
Control start temperature t _uAnd the temperature control is started
The heating time until the temperature changes greatly. Such a difference
On the other hand, in the method according to the second embodiment, the timed heating period
It will be dealt with by adjusting the interval, but the third
In the method according to the embodiment, the temperature control is started from the start of heating.
The heating time until time is automatically adjusted, and in any case
However, proper temperature control will be performed.

In the method according to the third embodiment,
The timing of shifting from the previous heating period to the intermediate heating period
To the value detected by the radiation thermometer 42 for the waveform of the transmitted light.
It is not always necessary to match the time when the peak appears
, The detected temperature at the time of shifting from the previous heating period to the intermediate heating period
Is the transition temperature t_dMust be higher
Is. If moving from the previous heating period to the intermediate heating period
The detected temperature at the point is the transition temperature t _dWhen lower, pre-heating
Immediately after shifting from the period to the intermediate heating period, the second heating period
Therefore, the same effect as the second embodiment is obtained.
Will end up.

In the third embodiment described above, when the preset time elapses from the start of the heating of the wafer W, the intermediate heating period is entered from the preceding heating period. The temperature around the detected value once showing the peak value is preset as the first transition temperature,
The intermediate heating period may be entered from the preceding heating period when the detection value of the radiation thermometer 42 reaches the first transition temperature. The intermediate heating period and the latter heating period are the same as those in the method according to the third embodiment, but the transition temperature (second transition temperature) from the intermediate heating period to the latter heating period is changed.
Are set to temperatures lower than the control start temperature and the first transition temperature, respectively. Even in such a method, the above-mentioned third
The same effect as that of the embodiment can be obtained.

The methods according to the first, second and third embodiments described above are different depending on the type of wafer, the type of heat treatment, the temperature control sequence, the state of the heat treatment furnace, etc. The optimum method may be selected from among these methods and used properly.

[0040]

According to the substrate heat treatment method of the first aspect of the present invention, it is possible to heat the substrate in a normal temperature or low temperature range without any trouble, and to detect it by a radiation thermometer without providing a thermocouple or the like. Accurate temperature control can be performed based on the value.

In the heat treatment method of the second aspect of the invention, the temperature of the substrate can be controlled more appropriately.

In the heat treatment methods of the inventions according to claims 3 and 4, the temperature control of the substrate can be optimally performed.

[Brief description of drawings]

FIG. 1 is a response waveform diagram showing a first embodiment of the present invention and showing a relationship between an actual temperature of a wafer and a detected value by a radiation thermometer when a heat treatment method according to the present invention is carried out.

FIG. 2 is a response waveform diagram showing the second embodiment of the present invention and showing the relationship between the actual temperature of the wafer and the detected value by the radiation thermometer when the heat treatment method according to the present invention is carried out.

FIG. 3 shows a third embodiment of the present invention, and is a response waveform diagram showing the relationship between the actual temperature of the wafer and the detected value by the radiation thermometer when the heat treatment method according to the present invention is carried out.

FIG. 4 is a diagram showing changes in detected temperature when the method according to the third embodiment of the present invention is carried out.

FIG. 5 is a schematic side sectional view showing an example of the configuration of a lamp annealing device.

6 is a block diagram showing an example of a temperature control system of the lamp annealing apparatus shown in FIG.

FIG. 7 is a response waveform diagram showing the relationship between the actual temperature of the wafer and the detected value by the radiation thermometer when the wafer is heated by supplying constant power to the lamp.

[Explanation of symbols]

10 heat treatment furnace 14 Light incident window 18 Wafer support ring 28 lamps 42a, 42b, 42c, 42 Radiation thermometer 46 Control device 48 power units W wafer

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 3K058 AA42 AA91 BA00 CA12 CA22                       CA70 CB15 CB18                 5F045 AA03 AA20 AB32 AF03 BB08                       DP02 DQ10 EK12 GB05

Claims (4)

[Claims] 1. A substrate is heated by irradiating the substrate with light from a heating light source, the temperature of the substrate is detected by a radiation thermometer, and the power supplied to the heating light source is determined based on the detection value of the radiation thermometer. In a substrate heat treatment method of controlling and heating a substrate in a predetermined sequence from room temperature, a constant power heating step of heating the substrate by supplying constant power to the heating light source, and a detection value by the radiation thermometer. And a control heating step of heating the substrate by controlling the power supplied to the heating light source based on the constant power at the time when the detection value by the radiation thermometer reaches a preset control start temperature. A method for heat treatment of a substrate, comprising: transferring from a heating step to the controlled heating step. 2. A timed heating period in which the constant power heating step supplies constant power to the heating light source to heat the substrate from the time when the heating of the substrate is started to the time when a preset time elapses. 2. The method for heat treating a substrate according to claim 1, further comprising: a temperature detection heating period in which a constant power is supplied to the heating light source to heat the substrate until a value detected by the radiation thermometer reaches the control start temperature. . 3. A pre-stage heating period in which the constant power heating step supplies constant power to the heating light source to heat the substrate from the time when the heating of the substrate is started to the time when a preset time elapses. A detected value by the radiation thermometer, an intermediate heating period in which a constant power is supplied to the heating light source to heat the substrate until a time point when the temperature is lower than the control start temperature and lower than a preset transition temperature, ,
2. The heat treatment method for a substrate according to claim 1, further comprising a post-heating period in which a constant power is supplied to the heating light source to heat the substrate until a value detected by the radiation thermometer reaches the control start temperature. 4. The constant power heating step applies constant power to the heating light source from the time when the heating of the substrate is started to the time when the detection value by the radiation thermometer reaches a preset first transition temperature. And the previous stage heating period for heating the substrate by supplying the detected value by the radiation thermometer,
Intermediate heating period in which constant power is supplied to the heating light source to heat the substrate until the temperature is lower than the control start temperature and the first transition temperature and is lower than the preset second transition temperature. 2. The method for heat treating a substrate according to claim 1, further comprising: a second heating period in which a constant power is supplied to the heating light source to heat the substrate until a value detected by the radiation thermometer reaches the control start temperature. .