JPH0837158A - Method and apparatus for heat treatment of substrate - Google Patents

Abstract

PURPOSE:To obtain the good reproducibility of a heat-treatment quality by a method wherein the difference in the time from the point of time when a dummy substrate is carried into a heat-treatment furnace and the point of time when a temperature inside the heat-treatment furnace becomes a carrying-into temperature after the dummy substrate has been carried out is computed and a prelimiary heating operation is finished when the difference becomes within a prescribed value. CONSTITUTION:The time (t1) from the point of time when a dummy substrate DM-L is carried into a heat-treatment furnace 10 to the point of time when a temperature inside the heat-treatment furnace 10 becomes a carrying-into temperature again so as to carry into a dummy substrate DM-R is measured. When the dummy substrate DM-R is carried out to the outside of the heat-treatment furnace 10 and the temperature inside the heat-treatment furnace 10 becomes the carrying-into temperature again, the dummy substrate DM-L is carried into the heat-treatment furnace 10. The time (t3) from the point of time to the point of time when the dummy substrate DM-R is carried into the heat-treatment furnace 10 is measured. When the difference (t3-t1) from the measured times is judged to be within a prescribed value, a process is shifted to the heattreatment process of an actual substrate W to be treated, and a preliminary heating process is finished.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses, for example, a lamp annealing device or a CVD device to house one substrate in a heat treatment furnace and heat the substrate to anneal the substrate.
The present invention relates to a substrate heat treatment method for performing heat treatment such as oxynitriding and film formation, and a heat treatment apparatus used for implementing the method, and particularly to a technique for preheating the inside of a heat treatment furnace.

[0002]

2. Description of the Prior Art Substrates are loaded into a flat heat treatment furnace one by one through an opening formed in one side surface of the heat treatment furnace, the openings are closed by a lid, and then the substrates are accommodated in the heat treatment furnace. On the other hand, in the single-wafer-type substrate heat treatment apparatus in which an active or inactive gas is introduced into the heat treatment furnace to perform annealing, oxynitridation, film formation, and various other heat treatments, the first substrate In order to obtain repetitive reproducibility of heat treatment quality, the inside of the heat treatment furnace is preheated before the first substrate is carried into the heat treatment furnace to thermally stabilize the heat treatment furnace. As a method of this preheating,
Conventionally, a dummy substrate is used, the dummy substrate is housed in a heat treatment furnace, and the dummy substrate is heated according to a heating program for actual heat treatment of the substrate, and the heat treatment cycle is repeated several times. Further, for example, in Japanese Examined Patent Publication No. 2-30179, the inside of the heat treatment furnace is heated according to an actual heating program, the temperature inside the furnace is once raised above the first set temperature, and after the peak temperature is passed, the second
The temperature is lowered below the set temperature, and the heating cycle is repeated at least twice, and in each heating cycle, from the time when the first set temperature passes when the temperature in the furnace rises to the time when the second set temperature passes when the temperature drops in the furnace. There is disclosed a heat treatment method in which the time required for the measurement is measured, and the preheating is terminated when the absolute value of the difference between the measurement times falls within a predetermined value.

[0003]

In the method of preheating the inside of the heat treatment furnace by repeating the heat treatment cycle of accommodating the dummy substrate in the heat treatment furnace and heating the dummy substrate according to the actual heating program, the number of times of the heat treatment cycle is repeated. Is decided by the operator. Therefore, the judgment of the end point of the preheating depends on the experience and intuition of the operator. For this reason, excess or deficiency occurs in the degree of preheating,
As a result, the reproducibility of the heat treatment quality of the first or several substrates that have been first heat-treated after preheating cannot be obtained.
There is a concern that such things will happen.

Further, in the method described in Japanese Patent Publication No. 2-30179, the dummy substrate is merely heated in the preheating step, and the dummy substrate is not heat-treated. Therefore, after the preliminary heating, the first substrate is heat-treated without heat-treating the substrate (dummy substrate) by the preliminary heating, and the second and subsequent substrates are heat-treated after the first substrate is heat-treated. In some cases, sufficient reproducibility of processing quality cannot be obtained. In particular, in the actual heat treatment, one side surface of the heat treatment furnace is opened in the process of lowering the temperature inside the heat treatment furnace after the substrate is program-heated, and the substrate after heat treatment is carried out from the heat treatment furnace, and after the substrate is carried out, When the temperature reaches a predetermined temperature, the substrate to be heat treated next is carried into the heat treatment furnace. However, when the preheating method as described in the above publication is used, the preliminary heating is temporarily performed. Even if the conditions for termination are met, the furnace condition when the first substrate is loaded into the heat treatment furnace after preheating and the second substrate after the first substrate is heat treated and removed from the heat treatment furnace A difference may occur between the subsequent substrate and the state inside the furnace when the substrate is carried into the heat treatment furnace. As a result, there is a problem that sufficient reproducibility of heat treatment quality cannot be obtained between the first substrate and the second and subsequent substrates.

The present invention has been made in view of the above circumstances, and the preheating in the heat treatment furnace can be performed without excess or deficiency before the substrate to be processed is loaded into the heat treatment furnace. When the first substrate to be processed is loaded into the heat treatment furnace after completion of the heat treatment, the inside of the furnace can be thermally stabilized almost completely, and the heat treatment quality of the first substrate and the second and subsequent substrates can be improved. It is an object of the present invention to provide a method for heat treatment of a substrate that can obtain excellent reproducibility, and an apparatus for heat treatment of a substrate that can suitably implement the method.

[0006]

According to the present invention, before the first substrate to be processed is loaded into the heat treatment furnace, the preheating and the end point of the preheating are determined by the following method. That is, when the temperature in the heat treatment furnace reaches a certain temperature, the dummy substrate is carried into the heat treatment furnace, the dummy substrate accommodated in the heat treatment furnace is heated by a certain heating program, and the dummy after heating is finished. The substrate is unloaded from the heat treatment furnace, and the series of unit steps from the loading of the dummy substrate into the heat treatment furnace to the unloading of the dummy substrate from the heat treatment furnace are repeated at least twice. Then, the time from the time when the dummy substrate is carried into the heat treatment furnace to the time when the temperature inside the heat treatment furnace reaches the carry-in temperature after the dummy substrate is carried out from the heat treatment furnace, and the measurement time in each unit process is measured. Is calculated, and when the difference is within a predetermined value, preheating is finished.

In the above method, it is preferable that two dummy substrates are used and the dummy substrates are alternately loaded into the heat treatment furnace and heated. Furthermore, it is preferable that the difference in measurement time in each unit process is calculated for the same dummy substrate.

Further, a heat treatment apparatus for carrying out the above method is
The following components were added to the conventional apparatus configuration including a heat treatment furnace, substrate holding / loading / unloading means, heating means, measuring means, and heating control means. That is, in the heat treatment apparatus according to the present invention, a substrate housing portion for housing a dummy substrate, a substrate transfer means for transferring the dummy substrate housed in the housing portion to the substrate holding / carrying-in / out means, and a dummy substrate That the temperature inside the heat treatment furnace measured by the temperature measuring means has reached the carry-in temperature designated by the carry-in temperature designating means. Temperature determining means for determining,
Substrate loading control means for controlling the substrate holding and loading / unloading means so that the dummy substrate is loaded into the heat treatment furnace when it is determined by the temperature determination means that the temperature in the heat treatment furnace has reached a constant loading temperature. And a time measuring means for measuring the time from the time when the dummy substrate is loaded into the heat treatment furnace to the time when the temperature in the heat processing furnace reaches the loading temperature after the dummy substrate is unloaded from the heat treatment furnace. The storage means for storing the measurement time measured by, and the difference between the measurement time newly measured by the clock means and the previous measurement time stored in the storage means is calculated, and the difference is within a predetermined value. There is a time discriminating means for discriminating whether or not there is, and a preheating end control means for terminating the preheating when the time discriminating means discriminates that the difference between the measurement times is within a predetermined value. It has been kicked.

In the apparatus having the above-mentioned structure, the two substrate storage sections are provided so that two dummy substrates can be stored, and the two dummy substrates are alternately loaded into the heat treatment furnace and heated. Substrate transfer control means for controlling the substrate transfer means may be provided. Further, it is preferable that the time discriminating means calculates the difference in measurement time for the same dummy substrate.

The above-mentioned temperature discriminating means, substrate loading control means, time measuring means, storage means, time discriminating means, preheating end control means and substrate transfer control means can be constituted by a microcomputer.

Further, a dummy substrate cooling mechanism for cooling the heated dummy substrate may be provided.

From the time when the heating of the dummy substrate is stopped,
The time until the temperature in the furnace reaches a constant temperature may be measured, and the preheating may be terminated based on the measured time.

[0013]

According to the substrate heat treatment method described above, and in the case where the substrate heat treatment is performed using the apparatus having the above-described structure, the substrate to be processed is placed in the heat treatment furnace before being carried into the heat treatment furnace. When the temperature reaches a constant loading temperature, the dummy substrate is loaded into the heat treatment furnace, and the dummy substrate is heated by a constant heating program and then unloaded from the heat treatment furnace. This series of unit steps is repeated twice or more, and from the time when the dummy substrate is loaded into the heat treatment furnace to the time when the temperature in the heat treatment furnace reaches the loading temperature after the dummy substrate is unloaded from the heat treatment furnace. Time is measured for each unit process. In this case, when the state of the heat treatment furnace becomes thermally stable, the measurement time approaches a constant value, and finally the measurement time becomes almost constant. Therefore, it is determined whether or not the difference in the measurement time in each unit process, for example, the value obtained by subtracting the measurement time in the first unit process from the measurement time in the second unit process is within a predetermined value, and as a result, If it is determined that the difference is within a predetermined value, it is determined that the state of the heat treatment furnace is thermally stable, and the preheating is terminated at that time. On the other hand, when the difference between the measurement times in the first and second unit processes is not within the predetermined value, the third unit process is performed and
It is determined whether a value obtained by subtracting the measurement time in the second unit process from the measurement time in the second unit process is within a predetermined value, and when it is determined that the difference in the measurement time is within the predetermined value, At that point, the preheating is terminated, and if not, the unit process is repeated until it is determined that the difference between the measurement times is within a predetermined value.

As described above, by using the dummy substrate, the dummy substrate is treated in the same process as the heat treatment of the actual substrate, and the unit process is repeated a plurality of times, so that the preheating of the heat treatment furnace can It is performed in a state close to the heat treatment of the substrate. Then, the judgment of the end point of the preheating is made based on the parameter that the state of the heat treatment furnace is considered to be thermally stable. When the eye substrate to be processed is loaded into the heat treatment furnace, the inside of the furnace is thermally almost completely stable. The thermal conditions in the furnace are reflected in its manner in which the temperature in the furnace decreases. The time from when the dummy substrate is loaded or when the heating of the dummy substrate is stopped until the temperature in the furnace reaches the loading temperature is a parameter that reflects the thermal state of the heat treatment furnace. The time until the temperature in the furnace reaches the carry-in temperature includes the process of the temperature decrease in the furnace for a long time, and the obtained measurement time is a parameter that accurately reflects the thermal state of the heat treatment furnace. Therefore, based on such measurement time, the thermal state of the heat treatment furnace can be detected with high accuracy,
The thermal stability in the furnace after preheating is also highly accurate.

When two dummy substrates are used and the dummy substrates are alternately loaded into the heat treatment furnace to be heated, the two dummy substrates are sequentially used to perform preheating efficiently in time. Done. Furthermore, when the difference in measurement time in each unit process is calculated for the same dummy substrate, the preliminary operation is performed in a similar manner to the actual heat treatment operation of the substrate, including the operation of loading / unloading the substrate into / from the heat treatment furnace. Since heating is performed, the state inside the furnace at the end of preheating can be more thermally stabilized, and
Even if the measurement time in a unit process varies due to the difference in the characteristics of each board, the difference in the measurement time is calculated between the same dummy boards, so the difference in the board characteristics affects the judgment at the end of preheating. Never give.

If a dummy substrate cooling mechanism for cooling the heated dummy substrate is provided, preheating using the dummy substrate in a low temperature state, which is closer to the actual heat treatment of the substrate, can be performed efficiently in time.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings.

First, FIG. 3 is a schematic perspective view showing an example of the structure of a heat treatment apparatus used for carrying out the substrate heat treatment method according to the present invention, and FIG. 4 is a control system of the apparatus. 3 is a block diagram showing an example of FIG. In FIG. 3, the heating lamp of the heat treatment furnace is not shown.

The heat treatment apparatus shown in FIGS. 3 and 4 is a lamp annealing apparatus, and this lamp annealing apparatus is formed of quartz glass or the like into a flat shape and a rectangular plane shape.
The heat treatment furnace 10 has an opening on one side, and the heat treatment furnace 10 accommodates substrates one by one. Opening on one side of heat treatment furnace 10
The lid 12 is configured to be openably and closably closed by a lid body 14, and a substrate is held on the inner surface side of the lid body 14 to hold a heat treatment furnace.
A susceptor 16 that is loaded into the heat treatment furnace 10 and discharged from the heat treatment furnace 10 is fixed. The lid 14 has a ball screw shaft 20 through a nut 18 fixed to the lid 14 as schematically shown in FIG.
The ball screw shaft 20 is connected to the rotary drive shaft of the motor 22. Then, by driving the motor 22 to rotate forward and backward, the lid 14 and the susceptor 16 can be integrally moved forward and backward with respect to the opening 12 of the heat treatment furnace 10. Further, on the outer side of the heat treatment furnace 10, a plurality of heating lamps 24 are provided so as to face the upper surface furnace wall and the lower surface furnace wall, respectively, and in the directions perpendicular to each other in the vertical direction.
Are lined up. Although not shown, the heat treatment furnace 10 has a gas control unit for supplying an active or inactive gas such as oxygen, ammonia, nitrogen, argon, or nitric oxide into the furnace through a pipe. The flow path is connected.

In the vicinity of the heat treatment furnace 10, as shown in FIG. 3, two cassette tables, left and right, on which the cassettes C for storing the substrates W before and after the heat treatment are positioned and mounted.
26 and 28 are provided. Below the respective cassette tables 26 and 28, two left and right dummy substrate storage units for storing the first dummy substrate DM-L and the second dummy substrate DM-R, respectively.
30 and 32 are provided. Further, on the lower side of the left dummy substrate housing portion 30, the substrate W and the dummy substrates DM-L, DM-R are provided.
A cooling mechanism 34 for cooling the
An alignment mechanism 36 for adjusting the position of the substrate is provided below the dummy substrate housing 32 on the right side. Further, the apparatus is provided with a substrate transfer mechanism 38 having a handling arm 40 for mounting and supporting the substrate. The handling arm 40 has a main body that can be moved up and down.
It is attached to the rail 42, and the main body 42 is attached to the rail 44.
And is driven by a driving device (not shown) (for example, a ball screw shaft and a motor) to be reciprocally movable. Then, by the substrate transfer mechanism 38, between the cassette C placed on the left and right cassette tables 26, 28, the alignment mechanism 36, the susceptor 16, the cooling mechanism 34, and the left and right dummy substrate storage sections 30, 32, respectively. The substrate W and the dummy substrates DM-L and DM-R are transferred.

Further, the heat treatment furnace 10 has a quartz tube inside thereof.
A monitor wafer 46 supported by 48 is arranged, receives infrared rays radiated from the monitor wafer 46, receives the temperature of the monitor wafer 46, and thus the heat treatment furnace 10.
A temperature sensor 50 for measuring the temperature inside is provided. The detection signal of the temperature sensor 50 is the A / D converter 52.
And is sent to a microcomputer (hereinafter referred to as “microcomputer”) 54. A memory 56 is provided in parallel with the microcomputer 54. The memory 56 has a substrate W and a dummy substrate DM-L,
Each data that specifies the carry-in temperature when carrying the DM-R into the heat treatment furnace 10 and the carry-out temperature when carrying out from the heat treatment furnace 10 is stored. Further, the microcomputer 54 determines, based on the detection signal of the temperature sensor, that the temperature inside the heat treatment furnace 10 has reached the carry-in temperature, and also that the temperature has reached a predetermined carry-out temperature, the heat treatment furnace 10 When it is determined that the internal temperature has reached the carry-in temperature, a control signal is sent to the sequencer (microcomputer) 58, a drive signal is sent from the sequencer 58 to the motor 22, and the substrate W or the dummy substrate DM held by the susceptor 16 is sent. -L, DM-R is carried into the heat treatment furnace 10,
When it is determined that the temperature in the heat treatment furnace 10 has reached the predetermined discharge temperature after heating, the susceptor is similarly processed.
Heated substrate W held on 16 or dummy substrates DM-L, DM
-A function to carry out R from the heat treatment furnace 10, send a control signal to the sequencer 58 to send a drive signal from the sequencer 58 to the substrate transfer mechanism 38, and operate the substrate transfer mechanism 38 to operate on each cassette 26, 28. Cassette C, alignment mechanism 3
6, susceptor 16, cooling mechanism 34 and each dummy substrate storage 3
Substrate W or dummy substrate DM-L, DM-R between 0 and 32
And a function to allow the lamp power source 62 to transmit a signal through the D / A converter 60 to change the voltage and current of the lamp power source 62, and the light source lamp 24 causes the lamp power source 62 to move into the heat treatment furnace 10. Stored substrate W or dummy substrate DM-
It has a function to control L and DM-R to be heated according to a certain heating program. Furthermore, the microcomputer
Reference numeral 54 denotes a temperature inside the heat treatment furnace 10 after the dummy substrates DM-L and DM-R are carried out from the heat treatment furnace 10 from the time when the dummy substrates DM-L and DM-R are carried into the heat treatment furnace 10. Function to measure the time until the temperature reaches the carry-in temperature, function to memorize the measured time, and calculate the difference between the newly measured time and the previously memorized time. A function of determining whether or not it is within a value, and when it is determined that the difference in measurement time is within a predetermined value, preheating is terminated, and the substrate transfer mechanism 38 is controlled via the sequencer 58.
It also has a function of starting the heat treatment operation of the first substrate W. The reference value for determining whether or not the difference between the measurement times is within a predetermined value is previously stored as data in the memory 56 as a value unique to each device.

Next, the preheating method will be described with reference to the flow chart shown in FIG.

First, the substrate transfer mechanism 38 takes out the first dummy substrate DM-L from the dummy substrate storage section 30 and transfers the dummy substrate DM-L onto the susceptor 16. And
At the time when the temperature in the heat treatment furnace 10 reaches a constant carry-in temperature,
The dummy substrate DM-L held on the susceptor 16 is heat-treated in the furnace 10
Bring it in. When the dummy substrate DM-L is housed in the heat treatment furnace 10, heating by the heating lamp 24 is started, and the dummy substrate DM-L is heat-treated according to a certain heating program. Then, the heating is stopped at a certain point. When you stop heating,
Although the temperature in the heat treatment furnace 10 is lowered, when the temperature in the heat treatment furnace 10 reaches a constant carry-out temperature, the dummy substrate DM-L held on the susceptor 16 is carried out of the heat treatment furnace 10. still,
After the first dummy substrate DM-L is transferred onto the susceptor 16, the substrate transfer mechanism 38 takes out the second dummy substrate DM-R from the dummy substrate storage section 32 and transfers it to the alignment mechanism 36 so that the alignment is performed in advance. Done. Then, the first dummy substrate DM
When -L is carried out of the heat treatment furnace 10, the substrate transfer mechanism 38 transfers the dummy substrate DM-L from the susceptor 16 onto the cooling mechanism 34, and then the second dummy that has been previously aligned. The substrate DM-R is taken out from the alignment mechanism 36 and placed on the susceptor 16. The first dummy substrate DM-L
Is cooled by the cooling mechanism 34 for a predetermined time, and then returned from the cooling mechanism 34 to the dummy substrate storage section 30.

When the temperature inside the heat treatment furnace 10 reaches a constant carry-in temperature again, the dummy substrate DM-R held on the susceptor 16 is carried into the heat treat furnace 10. Further, at this time, from the time when the first dummy substrate DM-L is loaded into the heat treatment furnace 10, the temperature in the heat treatment furnace 10 becomes the loading temperature again, and the second dummy substrate DM-R is loaded. The time t ₁ up to the point of time is measured and stored in the microcomputer 54. Then, the dummy substrate DM-R housed in the heat treatment furnace 10 is subjected to the same steps as described above.
After the heating is stopped, the dummy substrate DM-R is carried out of the heat treatment furnace 10 when the temperature inside the heat treatment furnace 10 reaches the carry-out temperature. The dummy substrate DM-R carried out of the heat treatment furnace 10 is returned to the dummy substrate housing section 32 from above the susceptor 16 through the cooling mechanism 34 in the same manner as described above. On the other hand, the first dummy substrate DM
As soon as -L is returned to the dummy substrate storage section 30, it is carried to the alignment mechanism 36 and brought into an aligned state. Then, when the second dummy substrate DM-R is transferred from the susceptor 16 to the cooling mechanism 34, the first dummy substrate DM-L is immediately transferred onto the susceptor 16 again. And the heat treatment furnace 10
When the temperature inside reaches the carry-in temperature again, the dummy substrate DM
-L is carried into the heat treatment furnace 10, and at this time, from the time when the second dummy substrate DM-R is carried into the heat treatment furnace 10 to the time when the temperature in the heat treatment furnace 10 reaches the carry-in temperature. Time t
₂ is measured and stored in the microcomputer 54.

Further, the same operation as described above is repeated for the first dummy substrate DM-L housed in the heat treatment furnace 10, and the heat treatment furnace 10 is loaded from the time when the dummy substrate DM-L is loaded into the heat treatment furnace 10. The time t until the second dummy substrate DM-R is loaded into the heat treatment furnace 10 when the temperature inside has reached the loading temperature.
Measure ₃ .

Here, in each unit process, the temperature in the heat treatment furnace 10 changes as shown in the time chart in FIG. 2, but when the dummy substrates DM-L and DM-R are carried into the heat treatment furnace 10. The time ta from when the heating is stopped to the time when the heating is stopped is constant because the heat treatment is performed according to a constant heating program. Dummy board DM-R, DM-L
The time tb until the time when the heat treatment is carried into the heat treatment furnace 10 changes depending on the state of the heat treatment furnace 10. That is, as the number of repetitions of the unit process increases, the heat treatment furnace 10 becomes in a thermally stable state, and the time tb becomes longer. Therefore, the dummy substrates DM-L and DM-R are loaded into the furnace from the time of loading. The measurement time tn (ta + tb) until the temperature reaches a constant loading temperature becomes longer, and the difference between the measurement times in each unit process becomes gradually smaller. Therefore, it is determined whether or not the difference between the measurement times is within a predetermined value, and the preheating is terminated when it is determined that the difference between the measurement times is within the predetermined value. In this case, in order to prevent the determination of the end time of preheating from being affected by the difference in the characteristics of the two dummy substrates, the difference in measurement time between the same dummy substrate, here, the first dummy substrate DM-L t 2n + 1-t 2n-1]
It was decided to calculate (n: positive integer). That is, the difference between the newly measured time t ₃ and the previously measured time t ₁ stored in the microcomputer 54 is calculated, and the difference [t ₃ −
It is determined whether or not t ₁ ] is within a predetermined value.

As a result of determining whether the difference [t ₃ −t ₁ ] of the measurement times is within a predetermined value, when it is determined that the difference [t ₃ −t ₁ ] is within the predetermined value, the heat treatment furnace After the second dummy substrate DM-R housed in the substrate 10 is heat-treated, it is carried out of the heat treatment furnace 10 and the actual heating process of the substrate W to be processed is started to complete the preliminary heating process. On the other hand, when it is determined that the difference [t ₃ −t ₁ ] is not within the predetermined value, the second dummy substrate DM-R is heated and then the first dummy substrate DM-L is further added in the same manner as above. Heating and heat treatment furnace 10
The time t ₅ from the time when the dummy substrate DM-L is carried into the heat treatment furnace 10 to the time when the temperature inside the heat treatment furnace 10 reaches the carry-in temperature is measured, and the measured time t ₅ and the microcomputer are measured. the difference between the previous measurement time t ₃ when stored [t ₅ -t _3] to determine whether it is within a predetermined value to. As a result, the difference [t ₅ −
When it is determined that t ₃ ] is within the predetermined value, the preheating step is ended in the same manner as described above, and when it is determined that it is not, the difference in measurement time [t 2n + 1−t 2n -1]
The above unit process is repeated until is within a predetermined value.

In the above embodiment, whether the difference [t 2n + 1-t 2n-1] between the measurement times of one dummy substrate DM-L of the two dummy substrates is within a predetermined value or not. However, for the other dummy substrate DM-R, it is also determined whether the difference [t 2n + 2-t 2n] (n: positive integer) between the respective measurement times is within a predetermined value. West,
The preheating may be terminated when it is determined that the difference between the measurement times of either one of the dummy substrates is within a predetermined value. If it is possible in terms of timing, one dummy substrate may be used to perform preheating in the same manner as described above, or three or more dummy substrates may be used. You may

Further, in the above embodiment, the time tn from the time of carrying in the dummy substrate until the temperature in the furnace reaches the carrying-in temperature.
However, only the time tb from the time when the heating of the dummy substrate is stopped until the temperature in the furnace reaches a constant temperature is measured, and the preheating is completed based on the measured time. You may. Further, if a dummy substrate cooling mechanism for cooling the heated dummy substrate is provided, preheating using a dummy substrate in a low temperature state that is closer to the actual heat treatment of the substrate can be performed efficiently in time. As shown in, if two dummy substrates are used,
When the preheating using one dummy substrate is finished, immediately perform the preheating using another dummy substrate, and at the same time, cool the previously used dummy substrate to the dummy substrate for the next preheating. Since it can be cooled by the mechanism, preheating can be performed particularly efficiently in time.

[0030]

Since the present invention is constructed and operates as described above, according to the method of heat treating a substrate according to the invention described in claims 1 and 10, the substrate to be processed is carried into the heat treatment furnace. Since the preheating of the heat treatment furnace can be performed without excess or deficiency before the heat treatment, the pretreatment can be performed for an unnecessarily long time to lengthen the entire processing time, or the degree of preheating is insufficient to improve the heat treatment quality of the substrate. It is possible to avoid that reproducibility is not obtained, and at the time when the first substrate to be processed is loaded into the heat treatment furnace after the completion of preheating, the inside of the furnace is in a thermally almost completely stable state. Therefore, good reproducibility of heat treatment quality can be obtained between the first substrate and the second and subsequent substrates.

According to the method of the second aspect of the present invention, the preheating is time-efficiently performed by sequentially using the two dummy substrates. Further, according to the method of the invention described in claim 3, the state in the heat treatment furnace at the end of the preheating can be thermally stabilized, and the two dummy substrates have different characteristics. However, since the difference does not affect the determination at the end of preheating, the reproducibility of the heat treatment quality of the substrate can be further improved.

When the apparatus according to the invention described in claims 4 and 11 is used to heat-treat the substrate, the method according to the invention according to claim 1 is preferably carried out to achieve the above effect. Further, by using the apparatus according to the inventions described in claims 6 and 7, it is possible to suitably carry out the method according to the inventions described in claims 2 and 3 to achieve the above effects. it can. Further, as described in claims 5 and 8, respectively, if each predetermined means is configured by a microcomputer, an actual device can be easily configured.

By using the apparatus according to the ninth aspect of the present invention, preheating using a dummy substrate in a low temperature state, which is closer to the actual heat treatment of the substrate, is performed with good time efficiency.

[Brief description of drawings]

FIG. 1 is a flowchart showing one embodiment of the present invention and illustrating a series of steps in a substrate heat treatment method.

FIG. 2 is a time chart showing a temporal change in the temperature in the heat treatment furnace in each unit process when the method according to the present invention is carried out and preheating is performed.

FIG. 3 is a schematic perspective view showing an example of the configuration of a substrate heat treatment apparatus used for carrying out the method according to the present invention.

4 is a block diagram showing an example of a control system of the device shown in FIG.

[Explanation of symbols]

 10 Heat treatment furnace 14 Lid 16 Susceptor 24 Heating lamp 26, 28 Cassette table 30, 32 Dummy substrate storage section 38 Substrate transfer mechanism 40 Handling arm 46 Monitor wafer 50 Temperature sensor 54 Microcomputer 56 Memory 58 Sequencer 62 Lamp power supply W Substrate DM-L, DM-R Dummy substrate

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Atsushi Yasue 322 Hazashishi Furukawa-cho, Fushimi-ku, Kyoto City Dainichi Screen Manufacturing Co., Ltd. Rakusai Factory (72) Inventor Mitsukazu Takahashi 322 Hazushi-shi Furukawa-cho, Fushimi-ku, Kyoto Address Dainichi Main Screen Manufacturing Co., Ltd. Rakusai Factory (72) Inventor Hiroki Kiyama 322 Hazashishi Furukawacho, Fushimi-ku, Kyoto City Dainichi Screen Manufacturing Co., Ltd. Rakusai Factory

Claims (11)

[Claims] 1. A substrate for preheating in a heat treatment furnace, terminating the preheating when the atmosphere in the furnace reaches a predetermined state, and accommodating substrates to be heat treated in the heat treatment furnace one by one. In the heat treatment method, the dummy substrate is loaded into the heat treatment furnace when the temperature in the heat treatment furnace reaches a certain temperature, and the dummy substrate stored in the heat treatment furnace is heated by a certain heating program, and heating is completed. The dummy substrate is unloaded from the heat treatment furnace, and the series of unit steps from loading the dummy substrate into the heat treatment furnace to unloading the dummy substrate from the heat treatment furnace are repeated at least twice, and the dummy substrate is put into the heat treatment furnace. The time from the time when the substrate was carried in to the time when the temperature in the heat treatment furnace reached the carry-in temperature after the dummy substrate was carried out of the heat treatment furnace was measured, and the difference in the measurement time in each unit process was calculated. Heat treatment method of the substrate, characterized in that the difference has finished preliminary heating when it is within a predetermined value. 2. The heat treatment method for a substrate according to claim 1, wherein two dummy substrates are used, and the dummy substrates are alternately loaded into a heat treatment furnace and heated. 3. Use of two dummy substrates, the dummy substrates are alternately loaded into a heat treatment furnace and heated, and the difference in measurement time in each unit process is calculated for the same dummy substrate. Item 2. A heat treatment method for a substrate according to Item 1. 4. A heat treatment furnace for accommodating the substrates one by one, a substrate holding / removing means for retaining the substrates and carrying them into the heat treatment furnace, and unloading them from the heat treatment furnace, and the heat treatment furnace accommodated in the heat treatment furnace. Heating means for heating the substrate, temperature measuring means for measuring the temperature in the heat treatment furnace, and heating control means for controlling the heating means to heat the substrate accommodated in the heat treatment furnace according to a certain heating program. In a substrate heat treatment apparatus including: a substrate storage unit for storing a dummy substrate; a substrate transfer unit for transferring the dummy substrate stored in the storage unit to the substrate holding / loading / unloading unit; The temperature in the heat treatment furnace, which is measured by the temperature measurement means, and the temperature in the heat treatment furnace that specifies the temperature for carrying in the heat treatment furnace,
A temperature discriminating means for discriminating that the carry-in temperature designated by the carry-in temperature designating means has been reached, and a dummy substrate at the time when the temperature discriminating means discriminates that the temperature in the heat treatment furnace has reached a constant carry-in temperature. Substrate loading / unloading means for controlling the substrate holding and loading / unloading means so that the dummy substrate is loaded into the heat treatment furnace, and the dummy substrate is loaded into the heat treatment furnace from the time when the dummy substrate is loaded into the heat treatment furnace. Time means for measuring the time until the temperature reaches the carry-in temperature, storage means for storing the measurement time measured by the time measuring means, and measurement time newly measured by the time measuring means and the storage A time discriminating means for calculating a difference from the previous measurement time stored in the means, and discriminating whether or not the difference is within a predetermined value; There thermal processing apparatus of the substrate, characterized by comprising a preheating termination control means for terminating the preheating when it is determined that becomes within a predetermined value. 5. The substrate heat treatment apparatus according to claim 4, wherein the temperature discriminating means, the substrate loading control means, the timing means, the storage means, the time discriminating means and the preheating end control means are constituted by a microcomputer. 6. A substrate having two substrate storage portions for storing two dummy substrates, and controlling the substrate transfer means so as to alternately carry the two dummy substrates into a heat treatment furnace and heat them. The substrate heat treatment apparatus according to claim 4 or 5, further comprising transfer control means. 7. The substrate heat treatment apparatus according to claim 6, wherein the time discriminating means calculates a difference in measurement time for the same dummy substrate. 8. The substrate heat treatment apparatus according to claim 6, wherein the substrate transfer control means comprises a microcomputer. 9. The substrate heat treatment apparatus according to claim 4, further comprising a dummy substrate cooling mechanism that cools the heated dummy substrate. 10. A substrate to be preheated in a heat treatment furnace, finished when the atmosphere in the furnace reaches a predetermined state, and housed one substrate at a time in the heat treatment furnace for heat treatment. In the heat treatment method, the dummy substrate is loaded into the heat treatment furnace, and the dummy substrate housed in the heat treatment furnace is heated by a certain heating program,
The heated dummy substrate is unloaded from the heat treatment furnace, and the series of unit steps from loading the dummy substrate into the heat treatment furnace to unloading the dummy substrate is repeated at least twice, The time from when the heating of the dummy substrate was stopped to the time when the temperature in the heat treatment furnace reached a constant loading temperature after the dummy substrate was unloaded from the heat treatment furnace, and the difference in the measurement time in each unit process was measured. And a preheating is finished when the difference is within a predetermined value. 11. A heat treatment furnace for accommodating the substrates one by one, a substrate holding / removing means for retaining the substrates and carrying them into the heat treatment furnace, and unloading them from the heat treatment furnace, and the heat treatment furnace accommodated in the heat treatment furnace. Heating means for heating the substrate, temperature measuring means for measuring the temperature in the heat treatment furnace, and heating control means for controlling the heating means to heat the substrate accommodated in the heat treatment furnace according to a certain heating program. In a substrate heat treatment apparatus including: a substrate storage unit for storing a dummy substrate; a substrate transfer unit for transferring the dummy substrate stored in the storage unit to the substrate holding / loading / unloading unit; The temperature in the heat treatment furnace, which is measured by the temperature measurement means, and the temperature in the heat treatment furnace that specifies the temperature for carrying in the heat treatment furnace,
A temperature discriminating means for discriminating that the carry-in temperature designated by the carry-in temperature designating means has been reached, and a dummy substrate at the time when the temperature discriminating means discriminates that the temperature in the heat treatment furnace has reached a constant carry-in temperature. Substrate loading / unloading means for controlling the substrate holding / loading / unloading means so that the dummy substrate is loaded into the heat treatment furnace, and after the dummy substrate is unloaded from the heat treatment furnace after the dummy substrate heating is stopped in the heat treatment furnace. Time measuring means for measuring the time until the temperature in the furnace reaches the carry-in temperature, storage means for storing the measurement time measured by this time measuring means, and measurement time newly measured by the time measuring means A time discriminating means for calculating a difference from the previously measured time stored in the storage means and discriminating whether or not the difference is within a predetermined value; and measuring by the time discriminating means. Thermal processing apparatus of a substrate the difference between is characterized by providing a preheating termination control means for terminating the preheating when it is determined that becomes within a predetermined value.