JP2002329717A - Heat treatment method of object and batch heat processing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat treatment method of an object, which can heat treat the object by using one recipe despite of the number of the objects, and to provide a heat treatment apparatus of batch heat processing system. SOLUTION: This heat treatment apparatus 1 comprises a reaction chamber 2 for housing a wafer boat 9 which holds a plurality of semiconductor wafers 10, a treatment gas introducing tube 13 for feeding the gas into the reaction chamber 2, an exhaust means capable of setting the inner pressure of the reaction chamber 2 to a predetermined value, and a controller 20 for controlling these. While the controller 20 memorizes heat treatment conditions depending on the predetermined number of semiconductor wafers 10, it calculates the heat treatment condition depending on the number of the semiconductor wafers 10 based on these heat treatment conditions and controls the inside of the reaction chamber 2 based on the calculated heat treatment condition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for heat-treating an object and a batch type heat treatment apparatus, and more particularly, to a method and a batch heat treatment method for an object to be heat-treated using a batch type heat treatment apparatus. The present invention relates to a thermal treatment apparatus.

[0002]

2. Description of the Related Art In a semiconductor device manufacturing process,
2. Description of the Related Art A batch-type heat treatment apparatus that performs a heat treatment such as a film formation process, an oxidation process, and a diffusion process on a large number of workpieces, for example, a semiconductor wafer, is used. As a batch-type heat treatment apparatus, for example, a heat treatment apparatus 51 as shown in FIG. 9 is used, and a semiconductor wafer is heat-treated as follows.

[0003] First, a reaction tube 52 having a double tube structure including an inner tube 52a and an outer tube 52b is heated to a predetermined temperature by a heater 53. Further, a wafer boat 55 containing a plurality of semiconductor wafers 54 is loaded into the reaction tube 52 (the inner tube 52a). Next, the gas inside the reaction tube 52 is exhausted from the exhaust port 56, and the pressure inside the reaction tube 52 is reduced to a predetermined pressure. When the pressure inside the reaction tube 52 is reduced to a predetermined pressure, the gas introduction tube 5
7, a processing gas is supplied into the inner pipe 52a, and the semiconductor wafer 54 is heat-treated.

In recent years, various kinds of semiconductor devices have been required, and it may be necessary to heat-treat various kinds of semiconductor wafers 54 in a so-called small lot. Therefore, in some cases, heat treatment of 150 semiconductor wafers 54 may be performed in one heat treatment using the heat treatment apparatus 51, and heat treatment of a small number of semiconductor wafers 54, for example, 100, 50, or 25 may be performed. May be done.

When performing heat treatment on a small number of semiconductor wafers 54, so-called dummy wafers are accommodated in a wafer boat 55, and heat treatment is performed on the semiconductor wafers 54 in a state in which the wafer boat 55 is fully loaded. Has been done. However, depending on the number of semiconductor wafers 54 to be heat-treated, dummy wafers are
5, the heat treatment step becomes complicated and takes time. Further, the dummy wafer is cleaned and used repeatedly for each heat treatment a plurality of times, but must be finally disposed of, which increases the cost of the semiconductor device.

Therefore, a small number of semiconductor wafers 54
When performing the heat treatment, the wafer boat 5
The wafer boat 5 does not have to be fully loaded.
A method of controlling the temperature and pressure of the reaction tube 52, the flow rate of the processing gas, and the like in a state where an empty area is provided in the inside of the reactor 5 is being studied. For example, a pressure sensor 58 is installed in the exhaust port 56, and the pressure in the reaction tube 52 is controlled so that the pressure detected by the pressure sensor 58 is maintained at a predetermined pressure.

[0007]

However, if the number of processed semiconductor wafers 54 accommodated in the wafer boat 55 is different, even if the pressure detected by the pressure sensor 58 is maintained at a predetermined pressure, the inside of the reaction tube 52 can be maintained. The pressure fluctuates. This is because the conductance in the reaction tube 52 fluctuates,
This is because the pressure in the reaction tube 52 fluctuates by the fluctuation of the conductance. Therefore, in order to control the pressure in the reaction tube 52 to a predetermined pressure, a recipe must be created for each number of processed semiconductor wafers 54 and the pressure in the reaction tube 52 must be controlled. There was a problem that it became complicated.

Further, when the pressure in the reaction tube 52 fluctuates according to the number of semiconductor wafers 54 accommodated in the wafer boat 55, the heat treatment speed, for example, the film formation rate in the heat treatment for forming a thin film on the semiconductor wafer 54 varies. As a result, it has been difficult to perform a desired heat treatment on the semiconductor wafer 54.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has been made in consideration of the above-described problems. It is an object to provide a method and a batch type heat treatment apparatus. Another object of the present invention is to provide a heat treatment method and a batch-type heat treatment apparatus for an object to be processed, which can easily perform heat treatment on the object to be processed, regardless of the number of the objects to be heat-treated. .

[0010]

According to a first aspect of the present invention, there is provided a method for heat-treating an object to be processed, comprising the steps of: And an object housing step of housing an object to be processed in the reaction chamber, and heating the reaction chamber to a predetermined temperature, exhausting the gas in the reaction chamber, and pressing the reaction chamber to a predetermined pressure. And a heat treatment step of supplying a processing gas into the reaction chamber set to a predetermined temperature and pressure by the condition setting step, and heat-treating the object to be processed. Based on the heat treatment conditions for heat treatment of a predetermined number of objects to be processed, calculate heat treatment conditions according to the number of objects to be heat treated, and control the heat treatment conditions in the reaction chamber to the calculated heat treatment conditions. Features.

According to this configuration, in the condition setting step, the heat treatment conditions corresponding to the number of the objects to be subjected to the heat treatment are calculated based on the heat treatment conditions in which a predetermined number of the objects are subjected to the heat treatment. Is controlled to the calculated heat treatment conditions. For this reason, it is not necessary to preliminarily set the heat treatment conditions for each number of the objects to be subjected to the heat treatment, and the heat treatment of the object is performed by one recipe. Further, heat treatment of the object to be processed is facilitated.

In the condition setting step, the reaction chamber may be controlled to a heat treatment condition corresponding to the number of the objects to be subjected to the heat treatment from a preset relational expression between the number of the objects to be processed and the heat treatment conditions. preferable. In this case, the heat treatment conditions corresponding to the number of the objects to be subjected to the heat treatment are calculated from the relational expression between the number of the objects to be processed and the heat treatment conditions, and the heat treatment conditions in the reaction chamber are controlled.

In the condition setting step, for example, when a predetermined number of workpieces smaller than the maximum number of workpieces that can be held by the workpiece holder are heat-treated, the condition is set according to the number of workpieces to be heat-treated. The inside of the reaction chamber is controlled according to heat treatment conditions.

In the condition setting step, for example, the reaction chamber is controlled to at least one heat treatment condition of a heat treatment pressure, a heat treatment speed, and a heat treatment time in accordance with the number of objects to be heat treated.

It is preferable to use, as the above-mentioned relational expression, a linear equation in which the relationship between the number of objects to be processed and the heat treatment conditions is obtained from the heat treatment conditions in which the objects to be processed are heat-treated with two different numbers of objects. In this case, the relational expression can be easily created.

A batch type heat treatment apparatus according to a second aspect of the present invention has a heating section which can be set to a predetermined temperature, and accommodates a workpiece holder for holding a plurality of workpieces. Having a gas supply pipe connected to the reaction chamber, a gas supply means for supplying a processing gas into the reaction chamber, and an exhaust pipe connected to the reaction chamber, wherein the gas in the reaction chamber is Exhaust means for exhausting gas from an exhaust pipe to set the reaction chamber to a predetermined pressure, and control means for controlling the reaction chamber to predetermined heat treatment conditions, wherein the control means comprises a predetermined number of substrates to be processed. Storing heat treatment conditions for heat-treating the body, calculating heat treatment conditions in accordance with the number of objects to be heat-treated based on the heat treatment conditions, and controlling the reaction chamber to the calculated heat treatment conditions, It is characterized by.

According to this configuration, the control means stores heat treatment conditions for heat-treating a predetermined number of workpieces.
The control means calculates heat treatment conditions in accordance with the number of objects to be heat-treated based on the stored heat treatment conditions, and controls the inside of the reaction chamber to the calculated heat treatment conditions. For this reason,
It is not necessary to preliminarily set the heat treatment conditions for each number of the objects to be subjected to the heat treatment, and the object to be treated is heat-treated with one recipe. Further, heat treatment of the object to be processed is facilitated.

The control means stores a relational expression between the number of workpieces to be subjected to heat treatment and the heat treatment conditions, and sets the reaction chamber to a heat treatment condition corresponding to the number of workpieces to be subjected to heat treatment based on the relational expression. It is preferable to control. In this case, the control means calculates a heat treatment condition corresponding to the number of the heat treatment objects to be subjected to the heat treatment from the relational expression between the number of the heat treatment objects and the heat treatment condition, and controls the reaction chamber to the calculated heat treatment conditions.

For example, in the case where a predetermined number of workpieces smaller than the maximum number of workpieces that can be held by the workpiece holder are heat-treated, the control means may perform a heat treatment in accordance with the number of workpieces to be subjected to the heat treatment. The reaction chamber is controlled according to conditions.

The heat treatment conditions are preferably, for example, at least one of a heat treatment pressure, a heat treatment rate, and a heat treatment time. Further, the relational expression is preferably a linear equation in which a relationship between the number of the objects to be processed and the heat treatment conditions is obtained from the heat treatment conditions in which the objects to be processed are heat-treated at two different numbers. In this case, the relational expression can be easily created.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a method for heat treating an object to be processed and a batch type heat treatment apparatus according to an embodiment of the present invention will be described. In this embodiment, a case where the vertical batch-type heat treatment apparatus shown in FIG. 1 is used as the batch-type heat treatment apparatus will be described as an example.

As shown in FIG. 1, the heat treatment apparatus 1 includes a substantially cylindrical reaction tube 2 whose longitudinal direction is directed vertically. The reaction tube 2 has a double tube structure composed of an inner tube 3 and an outer tube 4 with a ceiling that covers the inner tube 3 and is formed to have a certain distance from the inner tube 3. The inner tube 3 and the outer tube 4 are formed of a heat-resistant material, for example, quartz.

Below the outer tube 4, a manifold 5 formed of a stainless steel (SUS) formed in a cylindrical shape is arranged. The manifold 5 is airtightly connected to the lower end of the outer tube 4. The inner pipe 3 projects from the inner wall of the manifold 5 and is supported by a support ring 6 formed integrally with the manifold 5.

A lid 7 is arranged below the manifold 5, and the lid 7 can be moved up and down by a boat elevator 8. When the lid 7 is lifted by the boat elevator 8, the lower side of the manifold 5 is closed.

A wafer boat 9 made of, for example, quartz is placed on the lid 7. The wafer boat 9 is configured to be able to store a plurality of, for example, 150, objects to be processed, for example, semiconductor wafers 10 at predetermined intervals in the vertical direction.

A heat insulator 11 is provided around the reaction tube 2 so as to surround the reaction tube 2, and a heater 12 made of, for example, a resistance heating element is provided on the inner wall surface.

A plurality of processing gas introduction pipes 13 are inserted through the side surface of the manifold 5. In FIG. 1, only one processing gas introduction pipe 13 is illustrated. Processing gas inlet pipe 1
Reference numeral 3 is provided so as to face the inside of the inner tube 3. For example, as shown in FIG. 1, the processing gas introduction pipe 13 is inserted from the side of the manifold 5 below the support ring 6 (below the inner pipe 3). Then, a processing gas is introduced into the semiconductor wafer 10 from the processing gas introduction pipe 13.

A discharge port 14 is provided on a side surface of the manifold 5. The discharge port 14 is provided above the support ring 6 and communicates with a space formed between the inner tube 3 and the outer tube 4 in the reaction tube 2. Then, the processing gas is supplied from the processing gas introduction pipe 13 into the inner pipe 3 and the semiconductor wafer 10
Is performed, and the exhaust gas and the like generated by the heat treatment are discharged to the discharge port 14 through the space between the inner pipe 3 and the outer pipe 4. A purge gas supply pipe 15 for supplying nitrogen gas as a purge gas is inserted below the outlet 14 on the side surface of the manifold 5.

An exhaust pipe 16 is hermetically connected to the outlet 14. A pressure sensor 17 is arranged near the outlet 14 of the exhaust pipe 16. The pressure sensor 17 is connected to the reaction tube 2
Is a sensor that measures the pressure inside,
It is arranged so as to be located in the exhaust pipe 16 in the vicinity of 4.

The exhaust pipe 16 has an
A valve 18 and a vacuum pump 19 are provided. The valve 18 controls the pressure inside the reaction tube 2 to a predetermined pressure by adjusting the opening degree of the exhaust pipe 16. The vacuum pump 19 evacuates the gas inside the reaction tube 2 via the exhaust tube 16 and adjusts the pressure inside the reaction tube 2.

The boat elevator 8, the heater 12 for raising the temperature,
The processing unit 20 includes a processing gas introduction pipe 13, a purge gas supply pipe 15, a pressure sensor 17, a valve 18, and a vacuum pump 19.
Is connected. FIG. 2 is a block diagram showing an electrical configuration of the control unit 20.

As shown in FIG. 2, the control unit 20 includes a CPU
21, memory 22, input / output interface 23
And an auxiliary storage device 24. The CPU 21 executes the heat treatment of the present invention by executing the operation defined in the recipe stored in the memory 22. This recipe is stored in a portable recording medium such as a flexible disk or a CD-ROM, is transferred from the portable recording medium to the auxiliary storage device 24, and is stored in the memory 22 when the heat treatment is performed.

The input / output interface 23 is provided with a sensor provided in each part of the heat treatment apparatus 1, for example, a temperature sensor,
It is connected to the pressure sensor 17 and the like. And CPU2
1 measures the temperature, the pressure, etc. of each part of the heat treatment apparatus 1 with each sensor, and takes in the measurement data via the input / output interface 23.

The auxiliary storage device 24 is composed of, for example, a hard disk memory, and stores a recipe in which heat treatment conditions are set. This recipe is transferred to the memory 22 by the CPU 21. Then, based on the recipe and the measurement data such as the temperature and the pressure of each part of the heat treatment apparatus 1 measured by the sensor of each part and the recipe, the CPU 21
Output a control signal or the like to each part of the heat treatment apparatus 1,
Heat treatment time, pressure in the reaction tube 2, for example, the valve 18,
It controls the vacuum pump 19 and the like.

The auxiliary storage device 24 stores a relational expression between the number of the semiconductor wafers 10 to be subjected to the heat treatment and the heat treatment conditions, for example, the pressure in the reaction tube 2, the heat treatment speed, and the heat treatment time. This relational expression is created based on heat treatment conditions in a plurality of heat treatments in which the number of semiconductor wafers 10 is different, and the CPU 21 and the memory 21
2 Then, the CPU 21 calculates heat treatment conditions according to the number of semiconductor wafers 10 accommodated in the wafer boat 9 from this relational expression, and controls the inside of the reaction tube 2 to the calculated heat treatment conditions.

FIG. 3 is a graph showing a relational expression between the number of the semiconductor wafers 10 to be subjected to the heat treatment and the pressure in the reaction tube 2 as an example of a relational expression between the heat treatment conditions and the number of the semiconductor wafers 10 to be subjected to the heat treatment. This relational expression is created based on the pressure in the reaction tube 2 in a plurality of heat treatments in which the number of the semiconductor wafers 10 is different. Semiconductor wafer 1 used for creating relational expression
It is preferable that the number of “0” is greatly different.
The minimum number 25 of wafer wafers 9 is used. Hereinafter, a procedure for creating the relational expression will be described.

First, 150 semiconductor wafers 10 are accommodated in the wafer boat 9, and the accommodated semiconductor wafers 10 are subjected to a heat treatment to determine an optimum pressure in the reaction tube 2. Next, 25 semiconductor wafers 10 are accommodated in the wafer boat 9. For example, when a thin film is formed, the accommodated semiconductor wafers 10 are subjected to the same heat treatment so that the same film thickness is obtained. Find the pressure in 2. Subsequently, from the number of the semiconductor wafers 10 and the pressure in the reaction tube 2 at these numbers, a relational expression between the number (X) of the semiconductor wafers 10 and the pressure (Y) in the reaction tube 2, for example, Linear equation (Y = aX +
Create b).

For example, when the pressure in the reaction tube 2 with 150 semiconductor wafers 10 is 57.2 Pa (0.43 Torr).
r), when the pressure in the reaction tube 2 with 25 semiconductor wafers 10 is 53.4 Pa (0.40 Torr), when these values are substituted into a linear equation, 57.2 = 150a + b 53.4 = 25a + b Becomes When a and b are obtained from these two equations, a = 0.0
304, b = 52.64, and the relational expression between the number of semiconductor wafers 10 and the pressure in the reaction tube 2 is Y = 0.0304X + 52.64.

The reason why the pressure inside the reaction tube 2 is controlled in this way is that the pressure inside the reaction tube 2 changes due to the difference in the number of processed semiconductor wafers 10 accommodated in the wafer boat 9. This is because, where the semiconductor wafer 10 is provided in the reaction tube 2, the conductance in the reaction tube 2 decreases and the pressure in the reaction tube 2 decreases.
This is because the conductance in the reaction tube 2 does not decrease and the pressure in the reaction tube 2 does not easily decrease in a place having no. Therefore, regardless of the difference in the number of processed semiconductor wafers 10 accommodated in the wafer boat 9, the relationship between the number of semiconductor wafers 10 and the pressure in the reaction tube 2 is set so that the same heat treatment is performed in one recipe. The expression is stored and the control unit 2
0 (CPU 21) controls the pressure inside the reaction tube 2 to a pressure suitable for the relational expression.

Next, a method of heat-treating an object to be processed using the heat-treating apparatus 1 configured as described above will be described with reference to a recipe (time sequence) shown in FIG. ).
In this example, 50 semiconductor wafers 10
Is stored in the wafer boat 9
A description will be given of a heat treatment method (pressure control in the reaction tube 2) of the semiconductor wafer 10 that can obtain the same thickness of the silicon nitride film as in the case where 0 is fully loaded (150 semiconductor wafers 10 are accommodated). In the following description, the heat treatment apparatus 1
The operation of each unit constituting is controlled by the control unit 20 (CPU 21).

First, in a state where the lid 7 is lowered by the boat elevator 8, the wafer boat 9 containing a smaller number of semiconductor wafers 10 than the full load (150), for example, 50 semiconductor wafers 10 is placed on the lid 7. Place on. The 50 semiconductor wafers 10 were moved downward (downward in FIG. 1) of the wafer boat 9 and a plurality of dummy wafers were accommodated thereon. In addition, the wafer boat 9 is likely to be thermally non-uniform.
A plurality of side wafers were accommodated at the upper end and the lower end of the semiconductor wafer 10, and the temperature of the semiconductor wafer 10 was compensated.

Next, from the purge gas supply pipe 15 to the reaction pipe 2
A predetermined amount of nitrogen gas is supplied into the reactor, and the lid 7 is lifted by the boat elevator 8 to accommodate the wafer boat 9 (semiconductor wafer 10) in the reaction tube 2. Thereby, the semiconductor wafer 10 is accommodated in the reaction tube 2 and the reaction tube 2
Is sealed, and the semiconductor wafer 10 is loaded into the reaction tube 2 (loading step).

After sealing the reaction tube 2, the heater 12
Thereby, the inside of the reaction tube 2 is heated to a predetermined temperature, for example, 760 ° C. Further, the gas in the reaction tube 2 is discharged, and the pressure is reduced. Specifically, a predetermined amount of nitrogen gas is supplied from the purge gas supply pipe 15 into the reaction
While controlling the opening of 8, the vacuum pump 19 is driven,
The gas in the reaction tube 2 is discharged. The gas in the reaction tube 2 is discharged until the pressure in the reaction tube 2 becomes a predetermined pressure from the normal pressure. Here, the pressure in the reaction tube 2 when 50 semiconductor wafers 10 are accommodated is calculated from the relational expression between the number of the semiconductor wafers 10 and the pressure in the reaction tube 2. Reaction tube 2
Is 0.0304 × 50 + 52.64 = 54.
It is controlled to 16 Pa (0.41 Torr). And
The decompression operation and the heating operation are performed until the inside of the reaction tube 2 is stabilized at a predetermined pressure and temperature (stabilization step).

When the inside of the reaction tube 2 is stabilized at a predetermined pressure and temperature, the supply of nitrogen gas from the purge gas supply tube 15 is stopped. Then, a predetermined amount of SiH ₂ Cl ₂ gas as the processing gas, for example, 0.1 liter / min, a predetermined amount of NH ₃ gas, for example, 1 liter / min, and N as the inert gas are supplied from the processing gas introduction pipe 13. _Two gases are supplied in a predetermined amount, for example, 0.05 liter / min.

In the reaction tube 2, a reaction represented by the chemical formula 1 occurs, and a silicon nitride film (Si ₃
An N ₄ film is formed (heat treatment step).

Embedded image 10NH ₃ + 3SiH ₂ Cl ₂ → Si ₃ N ₄ +
6NH ₄ Cl + 6H ₂

When a silicon nitride film having a predetermined thickness is formed on the semiconductor wafer 10, the SiH
₂ Supply of Cl ₂ gas, NH ₃ gas, and N ₂ gas is stopped. Then, while controlling the opening degree of the valve 18, the vacuum pump 19 is driven to discharge the gas in the reaction tube 2, and a predetermined amount of nitrogen gas is supplied from the purge gas supply tube 15, and the inside of the reaction tube 2 is controlled. The gas is discharged to the exhaust pipe 16 (purge step). In order to reliably discharge the gas in the reaction tube 2, it is preferable to repeat the discharge of the gas in the reaction tube 2 and the supply of the nitrogen gas a plurality of times.

Finally, a predetermined amount of nitrogen gas is supplied from the purge gas supply pipe 15 to return the inside of the reaction tube 2 to normal pressure, and the wafer boat 9 (semiconductor wafer 10) is unloaded from the reaction tube 2 (unloading). Process).

FIG. 5 shows the pressure in the reaction tube 2 and the thickness of the silicon nitride film when 50 wafers 10 are accommodated in the wafer boat 9 formed as described above. Also,
In order to confirm the effect of the present invention, 100 wafers 10 are accommodated in the wafer boat 9 and the pressure in the reaction tube 2 (55. When the pressure was controlled to 68 Pa), a silicon nitride film was similarly formed on the semiconductor wafer 10.
FIG. 5 shows the pressure in the reaction tube 2 and the thickness of the silicon nitride film in this case. Further, the wafer boat 9 used to create the relational expression between the number of the semiconductor wafers 10 and the pressure in the reaction tube 2.
FIG. 5 also shows the pressure in the reaction tube 2 and the film thickness of the silicon nitride film when 150 and 25 semiconductor wafers 10 are accommodated in each case.

As shown in FIG. 5, regardless of the number of semiconductor wafers 10, the thickness of the silicon nitride film formed on the semiconductor wafer 10 is substantially the same, and the pressure in the reaction tube 2 is reduced It was confirmed that the thickness of the silicon nitride film could be made substantially the same by controlling the pressure to a value that conforms to the relational expression between the number of pieces and the pressure in the reaction tube 2. For this reason, the relational expression between the number of semiconductor wafers 10 and the pressure in the reaction tube 2 is stored in the control unit 20, and the reaction tube 2
By controlling the internal pressure to a pressure conforming to this relational expression, a silicon nitride film having a desired thickness can be formed on the semiconductor wafer 10 by one recipe irrespective of the number of semiconductor wafers 10. . Therefore, a silicon nitride film having a desired thickness can be easily formed on the semiconductor wafer 10 irrespective of the number of the semiconductor wafers 10.

As described above, according to the present embodiment, the number of semiconductor wafers 10 and
Since the relational expression with the pressure inside the reaction tube 2 is stored and the pressure in the reaction tube 2 is controlled to a pressure conforming to this relational expression, regardless of the number of the semiconductor wafers 10, the recipe on the semiconductor wafer 10 can be controlled by one recipe. A silicon nitride film having a desired thickness can be formed.

According to the present embodiment, the pressure in the reaction tube 2 is controlled to a pressure suitable for the relational expression between the number of semiconductor wafers 10 and the pressure in the reaction tube 2. Thus, a silicon nitride film having a desired thickness can be easily formed.

According to the present embodiment, the semiconductor wafer 10
Since the relational expression between the number of wafers and the pressure in the reaction tube 2 is created based on the pressure in the reaction tube 2 in two heat treatments in which the number of semiconductor wafers 10 is different, the relational expression is easily created. be able to. Furthermore, the number of semiconductor wafers 10 used to create the relational expression is significantly different (1).
(50 sheets and 25 sheets), the reliability of the relational expression can be improved.

The present invention is not limited to the above embodiment, and may be, for example, in the following case.

In the present embodiment, the present invention has been described by taking the relational expression between the number of semiconductor wafers 10 and the pressure in the reaction tube 2 as an example, but the relational expression between the number of semiconductor wafers 10 and predetermined heat treatment conditions is used. For example, a relational expression between the number of semiconductor wafers 10 and the heat treatment time (film formation time) may be used.
FIG. 6 shows a relational expression between the number of semiconductor wafers 10 and the film formation time at this number. This relational expression is expressed as follows:
Similarly to the relational expression between the number of
A film formation time for forming a silicon nitride film having a predetermined thickness on one semiconductor wafer 10 and a film formation time for obtaining a silicon nitride film having the same thickness on 25 semiconductor wafers 10 were obtained. An equation (Y = aX + b) is created. Film formation time for 150 semiconductor wafers 10
42 minutes (approximately 64 minutes 25 seconds), the film formation time for 25 semiconductor wafers 10 is 67.3 minutes (67 minutes 18 seconds), and the relational expression between the number of semiconductor wafers 10 and the film formation time is: Y =-
0.023X + 67.87. Thus, for example,
When the number of semiconductor wafers 10 is 50, the film formation time is 66.7.
By setting the time to 2 minutes (about 66 minutes 43 seconds), a silicon nitride film having the same thickness can be formed on the semiconductor wafer 10. By storing such a relational expression in the control unit 20 and controlling the film formation time to a time suitable for this relational expression, regardless of the number of semiconductor wafers 10, a single recipe can be used on the semiconductor wafer 10. A silicon nitride film having a desired thickness can be formed. Further, a silicon nitride film having a desired thickness can be easily formed on the semiconductor wafer 10.

Further, as shown in FIG. 7, a relational expression between the number of semiconductor wafers 10 and the heat treatment rate (film formation rate) may be used. This relational expression is also the same as the relational expression between the number of semiconductor wafers 10 and the pressure in the reaction tube 2, and the film formation rate for forming a silicon nitride film having a predetermined thickness on 150 semiconductor wafers 10, and 25 semiconductor wafers 10 In 10, a film forming rate for obtaining a silicon nitride film having the same thickness is obtained, and a linear equation (Y = aX + b) is created from the results of both. The film formation rate for 150 semiconductor wafers 10 is 2.33 nm.
/ Min, the film formation rate for 25 semiconductor wafers 10 is 2.23 nm / min, and the relational expression between the number of semiconductor wafers 10 and the film formation rate is Y = 0.0008X +
2.21. For this reason, for example, the semiconductor wafer 10
In the case of 50 wafers, a silicon nitride film having the same thickness can be formed on the semiconductor wafer 10 by setting the film forming rate to 2.25 nm / min. By storing such a relational expression in the control unit 20 and controlling the film forming rate to a speed suitable for the relational expression, the single recipe is applied to the semiconductor wafer 10 regardless of the number of the semiconductor wafers 10. A silicon nitride film having a desired thickness can be formed.
Further, a silicon nitride film having a desired thickness can be easily formed on the semiconductor wafer 10.

The present invention is not limited to the case where these relational expressions are used alone. For example, the relational expression between the number of semiconductor wafers 10 and the pressure in the reaction tube 2
These may be used together so that the relational expression between the number of semiconductor wafers 10 and the film formation time is used.

In the present embodiment, the relational expression between the number of semiconductor wafers 10 and the pressure in the reaction tube 2 is based on the pressure in the reaction tube 2 obtained by heat-treating the semiconductor wafers 10 with two different numbers. Although the present invention has been described by taking the case where the semiconductor wafer 10 is formed as an example, for example, as shown in FIG.
A relational expression between the number of semiconductor wafers 10 and the pressure in the reaction tube 2 is created by an approximate straight line based on the pressure in the reaction tube 2 at 0, 75, 100, 125, and 150 sheets. You may. In this case, the reliability of the relational expression can be improved. Further, this relational expression is not limited to one linear equation. For example, the relational equation may be created from two linear equations of less than 50 semiconductor wafers 10 and 50 or more.

In the present embodiment, the present invention has been described by taking as an example a case where the number of semiconductor wafers 10 and the pressure in the reaction tube 2 are defined by a relational expression consisting of a linear equation.
A database defining the pressure in the reaction tube 2 for the number of the semiconductor wafers 10 may be used.

In the present embodiment, the present invention has been described by exemplifying a case in which a silicon nitride film is formed on a semiconductor wafer 10, but the present invention can be applied to various heat treatments such as an oxidation treatment and a diffusion treatment. . Further, in the present embodiment, the present invention will be described by taking, as an example, a batch-type heat treatment apparatus of a batch-type vertical heat treatment apparatus having a double tube structure in which a reaction tube 2 includes an inner tube 3 and an outer tube 4. However, the present invention is not limited to this. For example, the present invention can be applied to a batch type heat treatment apparatus having a single pipe structure without the inner pipe 3. Further, the object to be processed is not limited to the semiconductor wafer 10, but may be applied to, for example, a glass substrate for LCD.

[0060]

As described above, according to the present invention,
Regardless of the number of objects to be subjected to the heat treatment, the object can be subjected to the heat treatment with one recipe. In addition, heat treatment of the object can be easily performed regardless of the number of objects to be subjected to the heat treatment.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a heat treatment apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating an electrical configuration of a control unit according to the embodiment of the present invention.

FIG. 3 is a graph showing a relational expression between the number of semiconductor wafers and the pressure in a reaction tube according to the embodiment of the present invention.

FIG. 4 is a diagram showing a recipe for explaining a method of forming a silicon nitride film according to an embodiment of the present invention.

FIG. 5 is a table showing the pressure in a reaction tube and the thickness of a silicon nitride film for a predetermined number of semiconductor wafers.

FIG. 6 is a graph showing a relational expression between the number of semiconductor wafers and a film forming time according to another embodiment of the present invention.

FIG. 7 is a graph showing a relational expression between the number of semiconductor wafers and a film forming rate according to another embodiment of the present invention.

FIG. 8 is a graph showing a relational expression between the number of semiconductor wafers and the pressure in a reaction tube according to another embodiment of the present invention.

FIG. 9 is a schematic view of a conventional heat treatment apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heat treatment apparatus 2 Reaction tube 3 Inner tube 4 Outer tube 9 Wafer boat 10 Semiconductor wafer 12 Heating heater 13 Processing gas introduction tube 14 Outlet 16 Exhaust tube 18 Valve 19 Vacuum pump 20 Control unit 21 CPU

Claims (10)

[Claims] An object-holding step of inserting an object-holding member holding a plurality of objects into a reaction chamber, and accommodating the object in the reaction chamber; And a gas set in the reaction chamber set at a predetermined temperature and pressure by the condition setting step. And a heat treatment step of heat-treating the object to be processed, wherein the condition setting step is performed according to the number of the objects to be heat-treated based on the heat treatment condition of heat-treating a predetermined number of objects to be processed. A heat treatment condition of the object to be processed, wherein the heat treatment condition is calculated and the reaction chamber is controlled to the calculated heat treatment condition. 2. The condition setting step includes controlling the reaction chamber to a heat treatment condition corresponding to the number of the objects to be subjected to the heat treatment from a preset relational expression between the number of the objects to be processed and the heat treatment conditions. The method for heat treating an object to be processed according to claim 1, wherein: 3. The condition setting step according to the number of objects to be heat-treated when a predetermined number of objects to be processed is smaller than the maximum number of objects that can be held by the object holder. The method according to claim 1, wherein the inside of the reaction chamber is controlled to a heat treatment condition. 4. The condition setting step is characterized in that the reaction chamber is controlled to at least one heat treatment condition of a heat treatment pressure, a heat treatment rate, and a heat treatment time in accordance with the number of objects to be heat treated. The heat treatment method for an object to be processed according to any one of claims 1 to 3. 5. A linear equation in which the relationship between the number of heat treatment objects and the heat treatment conditions is obtained from the heat treatment conditions of heat treatment of the heat treatment object at two different numbers, as said relational expression. The method for heat-treating an object according to claim 2. 6. A reaction chamber having a heating unit which can be set at a predetermined temperature and accommodating a workpiece holder holding a plurality of workpieces, and a gas supply pipe connected to the reaction chamber. A gas supply unit for supplying a processing gas into the reaction chamber; and an exhaust pipe connected to the reaction chamber, wherein the gas in the reaction chamber is exhausted from the exhaust pipe, and a predetermined An exhaust unit that can be set to a pressure; and a control unit that controls the inside of the reaction chamber to a predetermined heat treatment condition. The control unit stores heat treatment conditions in which a predetermined number of workpieces are heat treated, and stores the heat treatment condition. A batch-type heat treatment apparatus, wherein heat treatment conditions according to the number of objects to be heat treated are calculated based on the heat treatment conditions, and the inside of the reaction chamber is controlled to the calculated heat treatment conditions. 7. The control means stores a relational expression between the number of objects to be processed and the heat treatment conditions for performing the heat treatment, and reacts the reaction to the heat treatment conditions according to the number of the objects to be heat treated based on the relational expression. The batch type heat treatment apparatus according to claim 6, wherein the inside of the room is controlled. 8. A heat treatment apparatus according to claim 1, wherein said control means heat-treats a predetermined number of workpieces less than the maximum number of workpieces that can be held by said workpiece holder. The batch type heat treatment apparatus according to claim 6, wherein the inside of the reaction chamber is controlled to a condition. 9. The batch type heat treatment apparatus according to claim 6, wherein said heat treatment condition is at least one of a heat treatment pressure, a heat treatment rate, and a heat treatment time. 10. The relational expression is a linear equation in which a relationship between the number of heat treatment objects and the heat treatment condition is obtained from heat treatment conditions in which heat treatment is performed on heat treatment with two different numbers of heat treatment objects. The batch type heat treatment apparatus according to claim 7.