JPH04276079A - Plasma treating device and method for controlling the device - Google Patents

Abstract

PURPOSE:To prevent the generation of drawbacks in a plasma treating device. CONSTITUTION:A photodetector 5 is provided to observe the plasma emission 7a generated from the plasma 7 produced in a treating chamber 1 by a high-frequency power impressed from a high-frequency power source 3. If the high-frequency power is impressed and the plasma 7 is not produced after a specified time, the power source 3 is turned off, and the impression of a high-frequency power is stopped. Consequently, a high-frequency power is not impressed while the plasma is not produced, the treating chamber 1 and the power source 3 are not damaged, and labor accidents are obviated.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to plasma processing technology, and particularly to a technology that is effective when applied to plasma processing technology in the manufacturing process of semiconductor devices.

0002

BACKGROUND OF THE INVENTION For example, in the manufacturing process of semiconductor devices, electric energy such as high frequency waves or microwaves is applied to excite a reactive gas by turning it into plasma.
2. Description of the Related Art Plasma processing techniques are used to efficiently control the formation of thin films by chemical vapor deposition on semiconductor substrates and the etching of the thin films.

[0003] Regarding conventional plasma processing technology in the manufacturing process of semiconductor devices, for example, see "Electronic Materials" published by Kogyo Kenkyukai Co., Ltd., November 18, 1986.
There are documents such as the November 1986 issue reprint, pages 60 to 67.

0004

[Problems to be Solved by the Invention] By the way, in the case of a device that forms plasma by applying electrical energy such as high frequency waves or microwaves, as in the above-mentioned prior art, electrical energy is applied for plasma formation. Nevertheless, if a state in which plasma is not formed continues for some reason, there is a concern that the electrical energy that would be consumed for plasma formation will act on the power supply circuit, processing chamber, etc., causing damage to them. Furthermore, there is a problem in that high frequencies and microwaves leak to the outside, causing industrial accidents and electromagnetic noise.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a plasma processing technique that can reliably prevent troubles caused by abnormalities in plasma generation.

The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0007]

[Means for Solving the Problems] Among the inventions disclosed in this application, a brief overview of typical inventions will be as follows.
It is as follows.

That is, the plasma processing apparatus according to the present invention includes a plasma processing chamber in which an object to be processed is accommodated, a plasma generation power supply that applies electrical energy to form plasma in the plasma processing chamber, and a a control device connected to the plasma generation power source and the photodetection device, and controlling turning on and off of the plasma generation power source based on information from the photodetection device; The control unit controls the control unit when plasma emission is not observed for a predetermined period of time or longer while the plasma generation power is turned on, or when the observed plasma emission is not observed for a predetermined period of time or more while the plasma generation power is turned on. The plasma generation power source is cut off at the same time.

[0009] Furthermore, the plasma processing apparatus according to the present invention includes:
A plasma processing chamber in which a workpiece is housed, a plasma generation power source that applies electrical energy to form plasma in the plasma processing chamber, an exhaust means that evacuates the plasma processing chamber to a desired degree of vacuum, and plasma processing. The control section includes a pressure detection means for measuring the pressure in the room, and a control section that is connected to the plasma generation power source and the pressure detection means and controls turning on and off of the plasma generation power source based on information from the pressure detection means. In this system, when the pressure in the plasma processing chamber deviates from a predetermined range while the plasma generation power source is turned on, the plasma generation power source is cut off.

Furthermore, the method for controlling a plasma processing apparatus of the present invention includes observing the presence or absence of plasma light emission generated from plasma formed in a plasma processing chamber, and determining whether or not plasma light emission occurs for a predetermined period of time or longer while applying plasma generation power. When the state of not being observed continues, the application of plasma generation power is stopped.

Furthermore, the method for controlling a plasma processing apparatus of the present invention measures the pressure in the plasma processing chamber where plasma is formed by the plasma generation power, and when the pressure deviates from a predetermined range while the plasma generation power is being applied. This stops the application of plasma generation power.

0012

[Operation] According to the plasma processing apparatus of the present invention described above,
An abnormal state in which plasma is not formed despite the application of electrical energy for plasma generation is reliably prevented from continuing for more than a predetermined period of time. For this reason, electrical energy such as high-frequency power and microwaves that should be consumed to form plasma may act on the power supply circuit or plasma processing chamber, causing damage to the power supply circuit or plasma processing chamber, or causing damage to the power supply circuit or plasma processing chamber. It is possible to prevent industrial accidents caused by high frequencies and microwaves leaking from rooms, as well as various disturbances such as electromagnetic noise.

Furthermore, according to the method for controlling a plasma processing apparatus of the present invention, it is possible to reliably prevent an abnormal state in which plasma is not formed despite the application of plasma generation power from continuing for more than a predetermined time. be done. For this reason, energy such as high-frequency power and microwaves that should be consumed in plasma formation may act on the power supply circuit or plasma processing chamber, causing damage to the power supply circuit or plasma processing chamber, or causing plasma processing It is possible to prevent problems such as industrial accidents caused by high frequencies and microwaves leaking from rooms, as well as electromagnetic noise.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of a plasma processing apparatus according to an embodiment of the present invention and a method of controlling the same will be described in detail below with reference to the drawings. FIG. 1 is a schematic cross-sectional view schematically showing an example of the configuration of the plasma processing apparatus of this embodiment.

Inside the sealed processing chamber 1, a pair of electrodes 2 and 2a are arranged facing each other in parallel and horizontal positions. For example, a semiconductor substrate 4 is placed on the lower electrode 2a, which also serves as a sample stage. Further, the electrode 2a is grounded, and the upper electrode 2 opposite thereto is connected to a high frequency power source 3.

Although not particularly shown, the processing chamber 1 includes:
An exhaust mechanism for evacuating the processing chamber to a desired degree of vacuum, a reaction gas supply mechanism for introducing a reaction gas of a desired composition into the processing chamber 1, and the like are provided as necessary.

[0017] Plasma 7 is formed from a reaction gas (not shown) introduced into the processing chamber 1 by a gas supply mechanism (not shown) by high frequency power applied between the electrodes 2 and 2a. The semiconductor substrate 4 placed on the electrode 2a is subjected to desired processing such as formation of a thin film by chemical vapor deposition reaction or etching.

In this case, an observation window 1 is provided on the wall of the processing chamber 1.
Further, a photodetector 5 for observing plasma emission 7a generated from plasma 7 formed inside the processing chamber 1 is arranged outside the observation window 1a. Furthermore, this photodetector 5 is made up of, for example, a microcomputer, and is connected to a control section 6 that controls turning on/off of the high frequency power source 3.

The control unit 6 controls plasma emission 7 from the photodetector 5 when the high frequency power source 3 is turned on.
It is programmed to perform a control operation of cutting off the high-frequency power supply 3 and automatically stopping the application of high-frequency power to the processing chamber 1 when a state in which a is not detected for a predetermined period of time or longer occurs.

Hereinafter, an example of the operation of the plasma processing apparatus and its control method according to this embodiment will be explained in detail with reference to the flowchart of FIG. 2 and the like.

The inside of the processing chamber 1 is evacuated to a desired degree of vacuum, and a reaction gas (not shown) having a desired composition is introduced.

Thereafter, the control unit 6 turns on the high frequency power source (RF power source) 3 and starts applying a predetermined high frequency power to the electrodes 2 and 2a (step 100).

After a predetermined time T has elapsed (step 101), it is determined whether or not plasma emission 7a is detected from inside the processing chamber 1 by the photodetector 5 (step 102).

At this time, if it is found that the plasma emission 7a is detected by the photodetector 5, this indicates that the plasma 7 is normally formed inside the processing chamber 1, so that the normal Then, the desired plasma treatment is continued (step 103).

On the other hand, if it is determined in step 102 that the plasma emission 7a is not detected even though the predetermined time T has elapsed after the high-frequency power source 3 is turned on, there is some abnormality in the processing chamber 1. It is determined that
The high frequency power source 3 is cut off (step 104), and the application of high frequency power to the processing chamber 1 is stopped. In this step 104, the high frequency power source 3 is not simply cut off, but an operation such as issuing an alarm to the outside may be performed as necessary.

Due to such control operations, for example, even though high frequency power is being applied to the inside of the processing chamber 1 from the high frequency power supply 3, plasma 7 is not formed inside the processing chamber 1 for some reason. , the power that would be consumed to form the plasma 7 acts on the high-frequency power source 3 itself, the processing chamber 1, etc., thereby preventing the occurrence of equipment failures such as damage to the high-frequency power source 3 and the processing chamber 1. is prevented. In addition, it is possible to reliably prevent industrial accidents caused by high-frequency energy leaking from the processing chamber 1 without being consumed in forming the plasma 7, and electromagnetic noise in the working environment. .

Next, referring to FIG. 3, a plasma processing apparatus and a control method thereof, which are other embodiments of the present invention, will be described. In the case of this embodiment of FIG. 3, the processing chamber 1
The internal pressure is measured to determine whether there is an abnormality in plasma generation. In other words, the pressure inside the processing chamber 1 is one of the main factors for stable plasma formation in the processing chamber 1, so by observing the pressure inside the processing chamber 1, you can check whether the plasma 7 is being formed normally. It is used to determine whether there is a

A vacuum pump 9 is connected to the processing chamber 1 via an exhaust pipe 8, and the inside of the processing chamber 1 is evacuated to a desired degree of vacuum. In this case, a pressure sensor 10 for measuring the pressure inside the exhaust pipe 8, that is, the processing chamber 1, is attached to a part of the exhaust pipe 8 on the side of the processing chamber 1. The information thus obtained is configured to be input to the control unit 6.

When the pressure value in the processing chamber 1 obtained from the pressure sensor 10 deviates from a range suitable for forming plasma 7, the control section 6 cuts off the high frequency power source 3 and shuts down the processing chamber 1. stop the application of high frequency power to
This control operation is performed.

[0030] Therefore, for example, damage to the processing chamber 1, etc.
For some reason, the pressure inside the processing chamber 1 becomes a value unsuitable for the formation of plasma 7, and even though high frequency power is applied from the high frequency power source 3, no plasma is formed inside the processing chamber 1. Continuation of the abnormal state is reliably avoided, and as in the case of the embodiment shown in FIG. 1 described above, damage to the equipment due to high frequency power and occurrence of industrial accidents can be reliably prevented.

[0031] The invention made by the present inventor has been specifically explained based on examples, but the present invention is not limited to the above-mentioned examples, and can be modified in various ways without departing from the gist thereof. Needless to say.

For example, in the explanation of the above embodiment, the case where a high frequency power source is used for plasma generation is explained as an example of a plasma processing apparatus, but the invention is not limited to this, and the case where a high frequency power source is used for plasma generation is used. Needless to say, the present invention can also be applied to a plasma processing apparatus having a structure that generates plasma.

[0033] Furthermore, the object to be processed is not limited to a semiconductor substrate, but may be other articles.

[0034]

[Effects of the Invention] Among the inventions disclosed in this application, the effects obtained by the typical inventions are briefly explained as follows.
It is as follows.

That is, according to the plasma processing apparatus of the present invention, it is possible to reliably prevent the occurrence of troubles caused by abnormal plasma generation.

Furthermore, according to the method for controlling a plasma processing apparatus of the present invention, it is possible to reliably prevent the occurrence of troubles caused by abnormalities in plasma generation.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view schematically showing an example of the configuration of a plasma processing apparatus of the present invention.

FIG. 2 is a flowchart showing an example of the operation of the plasma processing apparatus and its control method according to the present invention.

FIG. 3 is a schematic cross-sectional view schematically showing an example of the configuration of the plasma processing apparatus of the present invention.

[Explanation of symbols]

1 Processing room 1a Observation window 2 Electrode 2a Electrode 3 High frequency power supply 4 Semiconductor substrate 5 Photodetector 6 Control section 7 Plasma 7a Plasma emission 8 Exhaust pipe 9 Vacuum pump 10 Pressure sensor

Claims (4)

[Claims] Claims: 1. A plasma processing chamber in which a workpiece is housed, a plasma generation power source that applies electrical energy to form plasma in the plasma processing chamber, and a plasma processing chamber that generates plasma from the plasma formed in the plasma processing chamber. a control section connected to the plasma generation power supply and the light detection means and controlling turning on and off of the plasma generation power supply based on information from the light detection means; In preparation, the control unit controls the control unit when the plasma emission is not observed for a predetermined period of time or more while the plasma generation power source is turned on, or when the observed plasma emission is not observed for a predetermined period of time or more while the plasma generation power source is turned on. A plasma processing apparatus characterized in that the plasma generating power source is cut off when the plasma generating power source is turned off. 2. A plasma processing chamber in which an object to be processed is accommodated, a plasma generation power source that applies electrical energy to form plasma in the plasma processing chamber, and a plasma processing chamber that is evacuated to a desired degree of vacuum. An exhaust means, a pressure detection means for measuring the pressure inside the plasma processing chamber, and a pressure detection means connected to the plasma generation power supply and the pressure detection means, and turning on and off the plasma generation power supply based on information from the pressure detection means. and a control unit that controls the plasma generation power supply, and the control unit operates to cut off the plasma generation power supply when the pressure in the plasma processing chamber deviates from a predetermined range while the plasma generation power supply is turned on. plasma processing equipment. 3. The presence or absence of plasma light emission generated from the plasma formed in the plasma processing chamber is observed, and when the state in which the plasma light emission is not observed for a predetermined period of time or more during the application of plasma generation power, the plasma A method for controlling a plasma processing apparatus, characterized by stopping application of generated power. 4. Measuring the pressure in a plasma processing chamber where plasma is formed by the plasma generation power, and stopping the application of the plasma generation power when the pressure deviates from a predetermined range while the plasma generation power is being applied. A method for controlling a plasma processing apparatus characterized by: