JP2001202138A - Method and device for controlling reaction room - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide reaction room controlling method and device capable of controlling the pressure of a reaction room to target pressure within a short time and reducing the consumption of reaction gas. SOLUTION: The reaction room control device is provided with a processing recipe storage means 7 for storing a gas flow rate and reaction room pressure corresponding to the contents of processing, an operation expression storage means 8 for storing an operation expression representing the characteristic of a pressure control means and an operation means 11 for operating the pressure control means for controlling the pressure of the reaction room 1. The operation means 11 comprises a derivation means for deriving the operation expression expressing the characteristic of the pressure control means by repeating measuring operation for finding out a control position for stabilizing the pressure of the reaction room 1 in accordance with the flow rate of reaction gas only by the coefficient value of the operation expression, a setting means for setting up the control position of the pressure control means on the found position by substituting the flow rate of reaction gas read out from a processing recipe for the operation expression and a control means for automatically controlling the pressure control means from a point of time that the pressure of the reaction room 1 approaches the reaction room pressure or the vicinity of the pressure so as to allow the pressure of the reaction room 1 to approach the reaction room pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control method for a reaction chamber and a control apparatus for the reaction chamber.

[0002]

2. Description of the Related Art When manufacturing a semiconductor device or a liquid crystal panel, various manufacturing apparatuses such as a dry etching apparatus, a thin film forming apparatus, and a doping apparatus are used according to a processing step of a wafer or a substrate.

Hereinafter, a dry etching apparatus for manufacturing a semiconductor device will be described as an example. As shown in FIG. 4, a conventional dry etching apparatus includes a gas supply unit 2 for supplying a reaction gas according to the content of processing performed in a reaction chamber 1.
And pressure control means for keeping the pressure in the reaction chamber 1 constant, and a control unit 6b.

The pressure control means comprises a pressure regulating valve 3, a pressure controller 4 for controlling the position of the pressure regulating valve 3, and a vacuum gauge 5 for acquiring the internal pressure of the reaction chamber 1. The control section 6 b comprises a processing recipe storage means. 7 and a central processing means 11.

In the dry etching apparatus configured as described above, when the reaction gas is supplied from the gas supply unit 2 to the reaction chamber 1, the flow rate of the reaction gas and the reaction chamber pressure are read from the processing recipe of the control unit 6b. Then, the flow rate of the reaction gas is controlled and introduced into the reaction chamber 1, and the pressure in the reaction chamber 1 is controlled by the pressure control means, whereby a semiconductor is manufactured.

[0006]

As a method of controlling the pressure in the reaction chamber 1, there is a method in which the internal pressure of the reaction chamber 1 is measured by a vacuum gauge 5 and controlled to a set value by feedback control. With such a method, there is a problem that it takes time for the pressure to reach the vicinity of the set value.

As feed-forward control, the position of the pressure regulating valve 3 is fixed at a predetermined position and the internal pressure of the reaction chamber 1 is controlled to a value close to the target pressure. Have also been proposed.

However, in this method, although the time required for the pressure to reach the vicinity of the set value can be shortened as compared with the pressure adjustment method using only the feedback control, an appropriate position of the pressure regulating valve 3 between the gas flow rate and the target pressure is determined in advance. It needs to be examined experimentally by hand.

An operation of fixing the gas flow rate and the position of the pressure control valve 3 and obtaining a pressure stable at that time is performed by changing the gas flow rate and the position of the pressure control valve 3 in a stepwise manner. When the relationship between the gas flow rate and the pressure is approximately determined in advance, and the pressure is controlled, the pressure regulating valve 3 is fixed to a position obtained from the relationship between the gas flow rate and the pressure previously determined as feedforward control, and the target pressure is controlled. A method of controlling the position of the pressure regulating valve by feedback control after controlling the pressure in the vicinity of has been proposed.

In this method, the gas flow rate and the position of the pressure regulating valve 3 can be automatically changed, so that there is no need for manual operation. However, in order to obtain the relationship between the gas flow rate and the pressure with high precision, the gas flow rate is required. It is necessary to implement a large number of combinations of the pressure control valve 3 and the position of the pressure regulating valve 3, which takes time and increases the amount of reaction gas used.

The present invention solves the above problems, and provides a reaction chamber control method and a reaction chamber control device capable of controlling the pressure of the reaction chamber to a target pressure in a short time and reducing the amount of use of the reaction gas. The goal is to

[0012]

According to the method for controlling a reaction chamber of the present invention, a measuring operation for obtaining an adjustment position at which the pressure of the reaction chamber is stabilized with respect to a gas flow rate is performed by using an arithmetic expression representing the characteristic of the pressure adjusting means. Is derived.

According to the present invention, the time required for obtaining the relationship between the gas flow rate, the pressure, and the adjustment position of the pressure adjusting means can be reduced, and the amount of the reaction gas used can be reduced. The control apparatus for a reaction chamber according to the present invention is characterized in that the configuration of the control unit is special.

According to the present invention, the method for controlling a reaction chamber according to the present invention can be easily realized.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the method for controlling a reaction chamber according to the first aspect of the present invention, the reaction chamber is controlled by reading a reaction gas flow rate and a reaction chamber pressure corresponding to the contents of the processing performed in the reaction chamber from a processing recipe. When performing the processing, the pressure control means for controlling the reaction chamber pressure, the measurement operation to find the adjustment position at which the pressure of the reaction chamber is stable with respect to the gas flow rate, the operation of the arithmetic expression representing the characteristics of the pressure control means The number of coefficients is executed to derive the arithmetic expression of the pressure control means, and the reaction gas flow rate read from the processing recipe is substituted into the arithmetic expression to set the adjusted position of the pressure control means at the determined position. When the pressure of the reaction chamber approaches the pressure of the reaction chamber read from the recipe or the pressure near the reaction chamber, the pressure control means is controlled to approach the pressure of the reaction chamber read from the processing recipe.

According to a second aspect of the present invention, there is provided a control apparatus for a reaction chamber for controlling a reaction chamber by reading a reaction gas flow rate and a reaction chamber pressure corresponding to the contents of processing performed in the reaction chamber from a processing recipe. A control device, a processing recipe storage means for storing a reaction gas flow rate and a reaction chamber pressure according to the content of the processing, an arithmetic expression storage means for storing an arithmetic expression representing a characteristic of the pressure control means, Operating means for operating pressure control means for adjusting the pressure of the chamber, and the operating means,
A deriving means for deriving an arithmetic expression by executing a measuring operation for obtaining an adjustment position at which the pressure of the reaction chamber is stabilized with respect to a flow rate of a reaction gas by the number of coefficients of an arithmetic expression representing characteristics of the pressure control means; Setting means for setting the adjustment position of the pressure control means to the determined position by substituting the reaction gas flow rate read from the processing recipe into the equation, and the pressure from the time when the pressure of the reaction chamber approaches the reaction chamber pressure or its vicinity. And control means for automatically controlling the control means to approach the reaction chamber pressure.

Hereinafter, a control apparatus and a control method for a reaction chamber according to the present invention will be described with reference to FIGS. 1 to 3 based on specific embodiments. Note that components having the same configuration as that of FIG. 4 showing a conventional example are denoted by the same reference numerals and described.

(Embodiment) In this embodiment, a dry etching apparatus used for manufacturing a semiconductor device will be described as a specific example of a control apparatus for a reaction chamber.

FIG. 1 differs from FIG. 4 which shows a conventional example in that the control unit 6a is specially configured to reduce the time required for controlling the pressure of the reaction chamber 1 and reduce the amount of reaction gas used. .

More specifically, the dry etching apparatus includes a gas supply unit 2 for supplying a reaction gas according to the content of the processing performed in the reaction chamber 1, a pressure control means for keeping the pressure in the reaction chamber 1 constant, 6a.

The pressure control means comprises a pressure regulating valve 3, a pressure controller 4 for controlling the position of the pressure regulating valve 3, and a vacuum gauge 5 for acquiring the internal pressure of the reaction chamber 1. The pressure controller 4 moves the pressure regulating valve 3 to a position given by the control unit 6a.
And a function of performing feedback control instructed by the control unit 6a so that the actual pressure of the reaction chamber 1 taken in by the vacuum gauge 5 becomes a given pressure.

The control section 6a comprises a processing recipe storage means 7 for storing a reaction gas flow rate and a reaction chamber pressure according to the contents of the processing, and an arithmetic expression storage means 8 for storing an arithmetic expression representing the characteristics of the pressure control means. A coefficient storage means 9 for storing a coefficient obtained from the gas flow rate, the pressure, and the position of the pressure control means, and a gas flow rate, a pressure, and a position of the pressure control means measured for obtaining a coefficient of an arithmetic expression. It comprises a measured value storage means 10 and a central processing means 11 for operating a pressure control means for adjusting the pressure of the reaction chamber 1.

The central processing means 11 performs a measurement operation for obtaining an adjustment position at which the pressure of the reaction chamber 1 becomes stable with respect to the flow rate of the reaction gas read from the processing recipe storage means 7. Deriving means for executing the number of coefficients of the arithmetic expression representing the characteristic to derive the arithmetic expression, and a position at which the adjustment position of the pressure control means is obtained by substituting the reaction gas flow rate read from the processing recipe storage means 7 into the arithmetic expression. And the reaction chamber pressure read from the processing recipe storage means 7 by automatically controlling the pressure control means from the time when the pressure of the reaction chamber approaches or near the reaction chamber pressure read from the processing recipe storage means 7. And control means for approaching

In the dry etching apparatus configured as described above, when the reaction gas is supplied from the gas supply unit 2 to the reaction chamber 1, the reaction gas flow rate and the reaction chamber pressure are stored in the processing recipe storage unit 7 of the control unit 6a. The etching process is read out from the stored processing recipe and is introduced into the reaction chamber 1 with the flow rate of the reaction gas being controlled, and the pressure in the reaction chamber 1 is controlled by the pressure regulating valve 3 and the pressure controller 4 as pressure control means. Is performed.

The pressure in the reaction chamber 1 is, specifically,
The control for changing the pressure of the reaction chamber 1 to the target pressure is performed in accordance with the procedure shown in FIGS. 2 and 3.

First, a coefficient of an arithmetic expression representing the characteristic of the pressure regulating valve 3 as the pressure control means is obtained by the procedure shown in FIG. In step S1, the gas flow rate F is set, in step S2, the number N of coefficients of the arithmetic expression stored in the arithmetic expression storage means 8 is set to an initial value 1, and in step S3, the pressure regulating valve 3 is set.
Is set to L.

If it is determined in step S4 that the pressure in the reaction chamber 1 has stabilized, then in step S5, the gas flow rate F, the position L of the pressure regulating valve 3, and the pressure P obtained by the vacuum gauge 5 are used as the measured value storage means 10. Is stored. If it is determined that the pressure in the reaction chamber 1 is not stable, the process waits until the pressure in the reaction chamber 1 is stabilized, and the confirmation is performed again.

In step S6, it is checked whether the number N of coefficients of the arithmetic expression matches the value set in step S2. If not, the number N is incremented by one in step S7. In step S8, the value of L is ΔL
The routine from the above steps S4 to S8 is repeated until the number N of the coefficients of the arithmetic expression is matched in step S6.

If it is determined in step S6 that the number N of the coefficients of the arithmetic expression matches, then in step S9, the measured value storage means 9
Are substituted into the arithmetic expressions of the arithmetic expression storage means 8 to create N sets of equations with coefficients as variables, and the simultaneous linear equations are solved. There is a general method for solving the system of linear equations, which can be used.

The obtained solution is a coefficient of an arithmetic expression. In step S10, the obtained coefficient is stored in the coefficient storage means 9. By the above procedure, an arithmetic expression for obtaining the position of the pressure regulating valve using the gas flow rate and the pressure as variables is derived.

When the operation formula is derived, the control of the reaction chamber 1 is performed according to the procedure shown in FIG. In step S1, the gas flow rate F is obtained from the processing recipe stored in the processing recipe storage means 7, and based on this gas flow rate F, the gas supply unit 2 is controlled at the flow rate F in step S2.

In step S3, the processing recipe storage means 7
The obtained gas flow rate F, pressure P, and coefficient obtained from the coefficient storage means 9 are substituted into the arithmetic expression stored in the arithmetic expression storage means 8, and the position L of the pressure regulating valve 3 is obtained.

In step S4, the position of the pressure regulating valve 3 is adjusted to the obtained position L and fixed by the pressure controller 4. In step S5, the actual pressure of the reaction chamber 1 measured by the vacuum gauge 5 is It monitors whether the pressure P read from the processing recipe storage means 7 or a pressure close to the pressure P is approached.

If it is determined that the intake pressure is not approaching the pressure P or its vicinity, the pressure of the reaction chamber 1 is adjusted again. A command is issued to the pressure controller 4 to perform feedback control.

According to this configuration, the measuring operation for obtaining the adjustment position of the pressure regulating valve 3 may be performed by the number of coefficients of the arithmetic expression, so that the time for acquiring the relational expression between the gas flow rate, the pressure, and the pressure adjusting means is reduced. It is possible to reduce the amount of reaction gas used.

Note that, depending on the shape of the pressure regulating valve 3 and the like, the arithmetic expression may be different in the range of the position L of the pressure regulating valve 3. In such a case, the coefficient is obtained by the above method for each range.
The position L of the pressure regulating valve 3 can be calculated by switching the arithmetic expression according to the set gas flow rate and pressure.

In the above description, a dry etching apparatus for manufacturing a semiconductor device has been described as an example of a control apparatus for a reaction chamber. However, the present invention is not limited to this. The present invention can be applied to a control device of a reaction chamber such as a doping device, and can be applied not only to a semiconductor device but also to a liquid crystal panel.

[0038]

As described above, according to the reaction chamber control method of the present invention, the pressure control means for controlling the pressure of the reaction chamber performs the measuring operation for finding the adjustment position where the pressure of the reaction chamber is stabilized with respect to the gas flow rate. The pressure control means is executed by the number of coefficients of the calculation expression representing the characteristic of the pressure control means to derive the calculation equation of the pressure control means. The adjustment position is set at the determined position, and from the time when the pressure of the reaction chamber approaches the reaction chamber pressure read from the processing recipe or the pressure in the vicinity thereof, the pressure control means is controlled to control the reaction chamber pressure read from the processing recipe. By controlling the pressures to approach each other, the time required to acquire the relational expression between the gas flow rate, the pressure, and the position of the pressure regulating valve can be reduced, and the amount of the reaction gas used can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a reaction chamber control device according to an embodiment of the present invention.

FIG. 2 is a flowchart for deriving coefficients of an arithmetic expression in the embodiment of the present invention.

FIG. 3 is a flowchart showing a control procedure of a reaction chamber in the embodiment of the present invention.

FIG. 4 is a diagram showing a configuration of a conventional semiconductor device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Reaction chamber 2 Gas supply part 3 Pressure regulating valve 4 Pressure controller 6a Control part

Continued on the front page F term (reference) 4K030 HA15 JA05 JA09 KA08 KA39 KA41 LA15 LA18 5F004 AA16 BC03 CA02 CA08 5F045 BB08 EE04 EE11 EG05 GB06 GB16 GB17 5H316 AA20 DD03 EE02 FF01 FF37 GG03 GG12 HH04 HH08H

Claims (2)

[Claims] 1. A pressure control means for reading a reaction gas flow rate and a reaction chamber pressure according to the content of a processing performed in a reaction chamber from a processing recipe and controlling the reaction chamber to control the reaction chamber pressure when performing the processing. For the gas flow rate, a measurement operation for finding an adjustment position at which the pressure of the reaction chamber is stabilized with respect to the gas flow rate is performed by the number of coefficients of the arithmetic expression representing the characteristics of the pressure control means, and the arithmetic expression of the pressure control means is derived. Substituting the reaction gas flow rate read from the processing recipe into the arithmetic expression to set the adjustment position of the pressure control means at the determined position, and setting the reaction chamber pressure read from the processing recipe or the pressure in the vicinity thereof to the reaction chamber pressure. A control method for controlling the pressure control means from the point of time when the pressure approaches to approach the reaction chamber pressure read from the processing recipe. 2. A reaction chamber control device for controlling a reaction chamber by reading a reaction gas flow rate and a reaction chamber pressure according to a content of a processing performed in a reaction chamber from a processing recipe. Processing recipe storage means for storing a reaction gas flow rate and a reaction chamber pressure; arithmetic expression storage means for storing an arithmetic expression representing the characteristics of the pressure control means; and arithmetic operation for operating the pressure control means for adjusting the pressure in the reaction chamber. Means for performing the measurement operation for obtaining an adjustment position at which the pressure of the reaction chamber is stabilized with respect to the flow rate of the reaction gas by the number of coefficients of an arithmetic expression representing the characteristic of the pressure control means. Deriving means for deriving an equation; setting means for setting the adjustment position of the pressure control means to the determined position by substituting the reaction gas flow rate read from the processing recipe into the arithmetic expression; Room And a control means for automatically controlling the pressure control means from the point of time when the pressure approaches to the reaction chamber pressure.