JPH0613327A - Gas pressure controller and controlling method for gas pressure - Google Patents

Abstract

PURPOSE:To accurately control the partial pressure of treating gas in a vacuum chamber. CONSTITUTION:A gas pressure controller is composed of a mass analyzer 6, a control unit 4 and a mass flow 5. A presence ratio of treating gas to other gas component in a vacuum chamber 1 is detected by the analyzer 6 and the gas is so supplied to the chamber 1 from the mas flow 5 that the partial pressure of treating gas in the chamber 1 becomes a predetermined value by a control signal generated from the unit 4 in response to its data. When this is applied to a semiconductor manufacturing apparatus, a film of a predetermined thickness controlled accurately on a substrate can be formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor manufacturing apparatus used for forming or processing a thin film such as sputtering, dry etching and CVD.
The present invention relates to an apparatus and method for controlling the pressure of a processing gas in a vacuum chamber.

[0002]

2. Description of the Related Art FIG. 2 shows a semiconductor manufacturing apparatus using a conventional gas pressure control device. A conventional gas pressure control device comprises a pressure gauge 3, a control unit 4 and a mass flow 5, which are equipped with a vacuum pump 2 in a vacuum chamber 1.
The semiconductor manufacturing apparatus is formed by connecting as shown in FIG. The pressure gauge 3 attached to the vacuum chamber 1 so as to measure the pressure in the vacuum chamber 1 is electrically connected to the control unit 4, the control unit 4 is electrically connected to the mass flow 5, and the mass flow 5 is the vacuum chamber. 1 is connected to a vacuum chamber 1 so as to supply a processing gas.

Next, the operation will be described. When wafer processing is performed in the vacuum chamber 1 using a processing gas suitable for the purpose, the pressure of the processing gas must be kept constant in order to perform uniform processing. For that purpose, the information of the momentary instruction value of the pressure gauge 3 attached to the vacuum chamber 1 is transmitted to the control unit 4, and the control signal corresponding to the information is transmitted from the control unit 4 to the mass flow 5. According to the control signal, the flow rate of the processing gas is controlled so that the pressure inside the vacuum chamber 1 becomes constant, and the processing gas is sent into the vacuum chamber 1.

[0004]

However, in this conventional gas pressure control device, the total pressure in the vacuum chamber 1 is measured, and the measured value is used to measure the processing gas in the vacuum chamber 1.
Since the amount of gas introduced into the vacuum chamber 1 is controlled, outgas is generated in the vacuum chamber 1 due to, for example, high temperature, and
When the atmosphere inside changes, the amount of the processing gas introduced changes according to the change in the total pressure including the partial pressure of the outgas. could not. Therefore, it was not possible to accurately control the processing of the wafer.

The present invention has been made in view of the above problems, and an object thereof is to provide an apparatus and method capable of controlling the pressure of only the processing gas in the vacuum chamber.

[0006]

The above object can be achieved by the following inventions.

The gas pressure control device of the first invention is a device for controlling the pressure of the processing gas in the vacuum chamber,
(a) means for detecting the abundance ratio of the processing gas and other gas components in the vacuum chamber, and (b) the detecting means.
means for feeding a controlled amount of the processing gas into the vacuum chamber according to the abundance ratio data from (a).

The gas pressure control device of the second invention is the above-mentioned means.
(b) is (b-1) a control unit that processes the above data and sends a signal indicating the amount of the above processing gas to be sent to the above chamber, and (b-2) the above control unit (b-1) Means for feeding the processing gas into the chamber according to the signal from.

The gas pressure control method of the third invention is a method of controlling the pressure of a processing gas in a vacuum chamber for forming or processing a thin film, comprising: (a) the processing gas in the vacuum chamber; The method further comprises a step of detecting the abundance ratio of the other gas component, and (b) a step of sending a controlled amount of the processing gas into the vacuum chamber according to the data relating to the abundance ratio from the detection means (a).

The gas pressure control method according to the fourth aspect of the present invention comprises the above steps.
(b) sends the processing gas into the chamber so that the partial pressure of the processing gas in the chamber becomes constant.

[0011]

The gas pressure control device according to the first aspect of the present invention can detect the abundance ratio of the processing gas and other gas components in the vacuum chamber and replenish only the insufficient amount of the processing gas into the vacuum chamber. The partial pressure of the process gas present can be controlled to a desired value.

The gas pressure control device according to the second invention is a control unit as means for feeding into the vacuum chamber an amount of the process gas controlled in accordance with data relating to the abundance ratio of the process gas and other gas components in the vacuum chamber. And a processing gas feeding means, which can be the same as those conventionally used, and can be easily manufactured.

Since the gas pressure control method of the third invention detects the existence ratio of the processing gas and other gas components in the vacuum chamber, only the insufficient amount of the processing gas is replenished in accordance with the detected value to obtain a vacuum. The partial pressure of the processing gas existing in the chamber can be controlled to a desired value.

According to the gas pressure control method of the fourth invention, since the partial pressure of the processing gas in the vacuum chamber is maintained at a constant value, the thin film is uniformly formed or processed.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a semiconductor manufacturing apparatus using the gas pressure control device of the present invention. The gas pressure control device of the present invention comprises a mass analyzer 6, a control unit 4 and a mass flow 5, which are connected to a vacuum chamber 1 equipped with a vacuum pump 2 as shown to form a semiconductor manufacturing device. The mass analyzer 6 attached to the vacuum chamber 1 is electrically connected to the control unit 4 so as to detect the abundance ratios of the processing gas, the outgas, and the gas components remaining before the processing gas is introduced into the vacuum chamber 1. The control unit 4 is electrically connected to the mass flow 5, and the mass flow 5 is connected to the vacuum chamber 1 so as to supply the processing gas to the vacuum chamber 1. As described above, this system is structurally obtained by replacing the pressure gauge 3 of the conventional system shown in FIG. 2 with the mass analyzer 6.
It can be easily designed and manufactured.

Next, the operation will be described. When wafer processing is performed in the vacuum chamber 1 using a processing gas according to the purpose, if the temperature around the inner wall surface of the vacuum chamber 1 is high, outgas is generated from the inner wall surface, and the pressure in the vacuum chamber 1 changes with time. Together with vacuum chamber 1
The composition of the internal atmosphere changes with time, and the partial pressure of the processing gas changes. Mass analyzer 6 connected to the vacuum chamber 1
Analyzes the atmosphere in the vacuum chamber 1 and detects the respective abundance ratios of the processing gas, the out gas, and the gas remaining before introducing the processing gas in the vacuum chamber 1. These abundance ratio data are transmitted to the control unit 4. In the control unit 4, the partial pressure of the processing gas is calculated from the data of its abundance ratio, the volume of the vacuum chamber 1, the performance of the vacuum pump 2, the processing gas supply amount of the mass flow 5 and the like, and the partial pressure of the processing gas in the vacuum chamber 1 is calculated. The amount of process gas to be added to bring the pressure to a predetermined value is calculated. A signal indicating the additional amount is transmitted to the mass flow 5, the additional amount of the processing gas is supplied from the mass flow 5 to the vacuum chamber 1, and the partial pressure of the processing gas in the vacuum chamber 1 becomes a predetermined value. The additional amount for obtaining the predetermined partial pressure of the processing gas is not only calculated as described above, but also the pressure in the vacuum chamber 1 is measured with a pressure gauge, and the value and data regarding the abundance ratio of the mass analyzer 6 are used. It is also possible to know the partial pressure of the processing gas from the above and calculate it from the value in the control unit 4. When the mass analyzer 6 has a function of measuring the pressure in the vacuum chamber 1, the data relating to the abundance ratio of the processing gas and the other gas component is obtained as the partial pressure of the processing gas and the other gas component, and the control unit 4 Calculates the amount of process gas to be added from the partial pressure of process gas.

In the semiconductor manufacturing apparatus using the gas pressure control device of the present invention, the semiconductor device and other devices can be processed or manufactured. Specifically, in the vacuum chamber 1, a thin film is formed on a predetermined substrate or processed on the substrate by sputtering, dry etching and CVD. By controlling the partial pressure of the processing gas with the gas pressure control device of the present invention, the thickness of the thin film to be formed is made constant or changed, or the processing degree and speed of the thin film are made constant or arbitrarily controlled. be able to. Further, by changing the partial pressure, it is possible to study the semiconductor process.

In the above embodiment, the mass analyzer 6 is used as a means for detecting the abundance ratio of the processing gas and other gas components in the vacuum chamber 1, and the processing gas is sent to the vacuum chamber 1 according to the signal from the control unit 4. Although the mass flow 5 is used as the means, any means may be used as long as it has the above functions, and the means is not limited to the mass analyzer and the mass flow.

[0019]

The gas pressure control device according to the first aspect of the present invention detects the existence ratio of the processing gas and other gas components in the vacuum chamber, and replenishes only the insufficient amount of the processing gas to exist in the vacuum chamber. It is possible to control the partial pressure of the processing gas used to a desired value. As a result, the formation or processing of the thin film in the vacuum chamber can be controlled arbitrarily.

The gas pressure control device of the second invention has a special function as a means for feeding into the vacuum chamber a processing gas in an amount controlled according to the data of the abundance ratio of the processing gas and other gas components in the vacuum chamber. Since it is provided with a general control unit and a processing gas feeding means that do not require, it can be easily manufactured.

Since the gas pressure control method of the third invention detects the abundance ratio of the processing gas and other gas components in the vacuum chamber, it supplies only a processing gas in an insufficient amount in accordance with the detected value to produce a vacuum. The partial pressure of the processing gas existing in the chamber can be controlled to a desired value. As a result, the thickness of the thin film formed on the substrate in the vacuum chamber or the speed of forming the thin film, or the speed and degree of processing of the thin film can be arbitrarily controlled.

According to the gas pressure control method of the fourth invention,
Since the partial pressure of the processing gas in the vacuum chamber is maintained constant, thin film formation and processing can be performed uniformly.

[Brief description of drawings]

FIG. 1 is a diagram showing a semiconductor manufacturing apparatus using a gas pressure control device of the present invention.

FIG. 2 is a diagram showing a semiconductor manufacturing apparatus using a conventional gas pressure control device.

[Explanation of symbols]

 1 vacuum chamber 2 vacuum pump 3 pressure gauge 4 control unit 5 mass flow 6 mass analyzer

Claims (4)

[Claims] 1. An apparatus for controlling the pressure of a processing gas in a vacuum chamber for forming or processing a thin film, comprising: (a) detecting the abundance ratio of the processing gas and other gas components in the vacuum chamber. And a means for (b) feeding the processing gas into the vacuum chamber in an amount controlled according to the abundance ratio data from the detection means (a). 2. A control unit, wherein said means (b) (b-1) processes said data and sends out a signal indicating the amount of said processing gas to be sent to said chamber, and (b-2) said A gas pressure control device according to claim 1, further comprising means for feeding the processing gas into the chamber according to the signal from the control unit (b-1). 3. A method for controlling the pressure of a processing gas in a vacuum chamber for forming or processing a thin film, comprising: (a) detecting an abundance ratio of the processing gas and other gas components in the vacuum chamber. And a step of: (b) sending a controlled amount of the processing gas into the vacuum chamber according to the data relating to the abundance ratio from the detection means (a). 4. The gas pressure control method according to claim 3, wherein the step (b) is to send the processing gas into the chamber so that the partial pressure of the processing gas in the chamber is constant.