JPH06275578A - Device and method for cleaning plasma treatment device - Google Patents

Abstract

PURPOSE:To effectively discharge foreign matters from a treatment chamber without receiving any influence from a flow passage and structure nor attaching and detaching components. CONSTITUTION:The title device is provided with a treatment chamber 3, an ultrasonic oscillator 1 which separates foreign matters adhering to the internal surface of the chamber 3 by ultrasonic vibrations, and a vacuum device 6 which discharges the foreign matters 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning apparatus and a cleaning method for a plasma processing apparatus which mainly cleans an inner wall of a processing chamber of a plasma processing apparatus of a semiconductor manufacturing apparatus, such as a dry etching apparatus, in which foreign matters are generated. It is a thing.

[0002]

2. Description of the Related Art In recent years, as a conventional example of a method for cleaning an inner wall of a plasma processing apparatus, (1) a method of repeatedly supplying and exhausting air in a processing chamber, (2) disassembling and cleaning the plasma processing apparatus, (3) A method using plasma irradiation is often used. First, with reference to FIG. 5, a method (1) of repeating air supply and exhaust in the processing chamber and a method (3) of using plasma irradiation will be described.

FIG. 5 is a schematic view of a conventional plasma processing apparatus. In FIG. 5, 2 is a foreign substance, 3 is a processing chamber, 4 is an air supply port, 5 is an exhaust port, 6 is a vacuum device, 7 is an anode, 8 is a cathode, and 9 is a high frequency power source. Regarding the method (1) of repeating air supply and exhaust in the processing chamber, the air supply port 4
The cleaning is advanced by supplying the gas from the exhaust gas and exhausting it from the exhaust port 5 together with the foreign matter 2 retained on the inner wall of the processing chamber 3.

Regarding the method (3) of using plasma irradiation, the cleaning gas introduced from the air supply port 4 is activated by the influence of plasma to become radicals and adheres to the inner wall of the processing chamber 3. Cleaning is advanced by reacting with the foreign matter 2 and exhausting the reaction product from the exhaust port 5.

[0005]

However, the above-mentioned structure has a problem that the yield in semiconductor manufacturing is reduced due to the influence of foreign matter for the following reasons. First, in the method (1) of repeating supply / exhaust of air in the processing chamber, the influence of the gas flow path is large, and it is impossible to exhaust foreign matter existing in a so-called gas reservoir portion that is not in the gas flow path. As a result, the amount of foreign matter is cumulatively increased in the processing chamber.

Next, the method (2) of disassembling and cleaning the plasma processing apparatus is not applicable to a plasma processing apparatus in which it is difficult to open the processing chamber to the atmosphere due to the use of dangerous gas or the like. In addition, in the case of a plasma processing apparatus having a complicated structure or in which it is difficult to attach / detach component parts, the number of foreign substances immediately after cleaning increases rapidly because the processing chamber cannot be sufficiently cleaned.

Further, in the method (3) using plasma irradiation, since the end point of cleaning is not exactly known, the material of the inner wall of the processing chamber is damaged by the excessive irradiation of plasma, and foreign matters increase due to insufficient cleaning. To do. Therefore,
In view of the above-mentioned problems, an object of the present invention is to effectively remove foreign substances in the processing chamber without being affected by the flow path or structure, and without requiring attachment / detachment of parts, and open the processing chamber to the atmosphere. A cleaning device and a cleaning method for a plasma processing apparatus, which can prevent the occurrence of cleaning and further clarify the end point of cleaning.

[0008]

According to a first aspect of the present invention, there is provided a cleaning device for a plasma processing apparatus, wherein a processing chamber and a foreign substance attached to an inner surface of the processing chamber are ultrasonically vibrated to be removed. It is provided with a sound wave oscillating device and exhaust means for exhausting foreign matter. According to a second aspect of the present invention, in the cleaning apparatus of the plasma processing apparatus according to the first aspect, the means for exhausting foreign matter is a vacuum device, and the ultrasonic oscillator can be operated in a state in which the degree of vacuum in the processing chamber is maintained in a reduced pressure state. It is characterized by that.

According to a third aspect of the present invention, there is provided a cleaning device for a plasma processing apparatus according to the first or second aspect, further comprising a cleaning gas supply means for constantly supplying a constant flow rate of the cleaning gas into the processing chamber. is there. According to a fourth aspect of the present invention, in the cleaning device of the plasma processing apparatus according to the third aspect, the cleaning gas is an inert gas.

According to a fifth aspect of the present invention, there is provided a cleaning apparatus for a plasma processing apparatus, which ultrasonically vibrates a processing chamber having a cleaning liquid inlet and a cleaning liquid outlet and foreign matter attached to the inner surface of the processing chamber. An ultrasonic oscillator and a cleaning liquid supply / discharge device for supplying / discharging the cleaning liquid to / from the processing chamber through the cleaning liquid inlet and the cleaning liquid outlet are provided. According to a sixth aspect of the present invention, in the cleaning apparatus of the plasma processing apparatus according to the fifth aspect, the cleaning liquid supply / discharge device circulates the cleaning liquid in the processing chamber and has a foreign matter separating means for the cleaning liquid.

According to a seventh aspect of the present invention, there is provided a cleaning device of the plasma processing apparatus according to the fifth or sixth aspect, wherein the cleaning liquid is water, ethyl alcohol or acetone, or a mixture thereof. A cleaning device for a plasma processing apparatus according to claim 8 is the cleaning apparatus according to any one of claims 1 to 7, wherein a heater is provided in the processing chamber.

A cleaning apparatus for a plasma processing apparatus according to a ninth aspect is the cleaning apparatus according to any one of the first to eighth aspects.
It has a light source and a light receiving part for receiving the light of this light source, a processing chamber is arranged between the light source and the light receiving part, and a measurement window through which the light of the light source can pass through the processing chamber is provided in the processing chamber. . According to a tenth aspect of the present invention, there is provided a method of cleaning a plasma processing apparatus, wherein the ultrasonic wave oscillating apparatus is operated at the same time as the plasma processing operation of the processing chamber.

[0013]

According to the cleaning apparatus of the plasma processing apparatus of the first aspect, when the ultrasonic wave oscillating apparatus is operated, the foreign matter adhering to the inner surface of the processing chamber is detached from the inner surface by the ultrasonic vibration and is exhausted to the outside of the processing chamber by the exhaust means. To be done. Therefore, unlike the prior art, it is possible to effectively exhaust foreign matter in the processing chamber without being affected by the gas flow path in the processing chamber or the structure of the processing chamber, and without requiring the attachment and detachment of internal parts. it can.

According to a second aspect of the cleaning apparatus of the plasma processing apparatus of the present invention, in the first aspect, the foreign matter exhausting means is a vacuum device, and the degree of vacuum in the processing chamber is maintained at a reduced pressure.
Since the ultrasonic wave oscillating device is made operable, in addition to the function of the first aspect, the polymer and reaction products attached to the inner wall of the processing chamber are peeled off at the stage of growing into a foreign substance to reduce particle attachment to the wafer. Further, even if the separated foreign matter adheres to the inner wall of the processing chamber, the foreign matter is desorbed by the ultrasonic vibration, so that the foreign matter does not stay in the processing chamber for a long time.

According to a third aspect of the present invention, there is provided a cleaning apparatus for a plasma processing apparatus according to the first or second aspect, which has a cleaning gas supply means for constantly supplying a constant flow rate of the cleaning gas into the processing chamber. In addition to the function of, foreign matter can be completely exhausted. According to the cleaning device of the plasma processing apparatus of claim 4, in claim 3, since the cleaning gas is an inert gas, it has the same effect as in claim 3.

According to the cleaning device of the plasma processing apparatus of the fifth aspect, in addition to the effect of the first aspect, the processing chamber filled with the cleaning liquid is ultrasonically vibrated to remove foreign matters and discharge the cleaning liquid. It is possible to remove foreign substances to the outside of the processing chamber without exposing the inside of the processing chamber to the atmosphere as in the conventional case. According to the cleaning device of the plasma processing apparatus of claim 6, in claim 5, the cleaning liquid supply / drainage device circulates the cleaning liquid in the processing chamber and has foreign matter separating means for the cleaning liquid. Besides, foreign matter can be removed efficiently and cleaning liquid can be saved.

According to the cleaning device of the plasma processing apparatus of claim 7, in claim 5 or 6, the cleaning liquid is water, ethyl alcohol or acetone, or a mixture thereof. Has the same effect as. According to the cleaning device of the plasma processing apparatus of claim 8, in any one of claims 1 to 7,
Since the heater is provided in the processing chamber, in addition to the effects of the claims, foreign matter does not easily adhere to the inner wall of the processing chamber during plasma processing operation of the processing chamber, and cleaning liquid remaining when cleaning with cleaning liquid Since it can be vaporized, the residual cleaning liquid can be eliminated in a short time.

According to a ninth aspect of the present invention, there is provided a cleaning device for a plasma processing apparatus according to any one of the first to eighth aspects, which has a light source and a light receiving section for receiving light from the light source.
Since the processing chamber is arranged between the light source and the light receiving unit and the measurement window through which the light from the light source can pass through is provided in the processing chamber, it has the effects of the claims and the inner surface of the measurement window as cleaning progresses. Since the foreign matter adhering to the will be removed, the intensity of the light received by the light receiving part will increase, and it will be possible to detect that the cleaning is completed at the point where the intensity reaches its maximum.
The end point of cleaning can be clarified.

According to the cleaning method of the plasma processing apparatus of the tenth aspect, the plasma processing operation of the processing chamber is performed, and at the same time, the ultrasonic oscillating apparatus is operated.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A cleaning device for a plasma processing apparatus according to a first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic diagram of a plasma processing apparatus having a cleaning device according to the first embodiment. In FIG. 1, 1 is an ultrasonic oscillator, 2 is a foreign substance, 3 is a processing chamber, 4 is an air supply port,
Reference numeral 5 is an exhaust port, 6 is a vacuum device, 7 is an anode, 8 is a cathode, and 9 is a high frequency power source.

The cleaning device includes a processing chamber 3, an ultrasonic oscillator 1 provided in the processing chamber 3 for ultrasonically vibrating and detaching the foreign matter 2 adhering to the inner surface of the processing chamber 3, and the foreign matter. And a vacuum device 6 which is an exhaust means for exhausting 2. Next, the operation will be described with reference to FIG. First, 100 sccm of N ₂ gas as a cleaning gas is introduced from the cleaning gas supply means (not shown) through the air supply port 4, and the vacuum device 6 is adjusted so that the pressure in the processing chamber 3 is maintained at 100 mTorr. Next, the ultrasonic wave oscillating device 1 is operated to remove the foreign matter 2 adhering to the inner wall of the processing chamber 3. Finally, the separated foreign matter 2 is exhausted from the exhaust port 5, and the cleaning of the inner wall of the processing chamber 3 is completed.

According to this embodiment, when the ultrasonic oscillating device 1 is operated, the foreign matter 2 adhering to the inner surface of the processing chamber 3 is detached from the inner surface by the ultrasonic vibration, and the processing chamber 3 is evacuated by the vacuum device 6 which is the exhaust means. Exhausted to the outside. Therefore, unlike the conventional case, the foreign matter 2 in the processing chamber 3 can be removed without being affected by the gas flow path in the processing chamber 3 or the structure in the processing chamber 3 and without the need to attach or detach the internal parts. Can be effectively exhausted.

In order to operate the ultrasonic wave oscillating device 1 while maintaining the degree of vacuum in the processing chamber 3 at a reduced pressure by using the vacuum device 6 as a means for exhausting foreign matter, the foreign matter is attached to the inner wall of the processing chamber 3. The polymer and the reaction product are peeled off at the stage of growing into the foreign substance 2 to reduce particle adhesion to the wafer. Even if the separated foreign matter 2 adheres to the inner wall of the processing chamber 3, the foreign matter does not stay in the processing chamber 3 for a long time because it is desorbed by ultrasonic vibration.

Further, since the cleaning gas supply means for supplying the cleaning gas into the processing chamber 3 at a constant flow rate is provided at all times, the foreign matter can be completely exhausted. Also, N _{2 is} used as a cleaning gas.
A gas was used, but it may be another inert gas. By installing a heater (not shown) around the processing chamber 3, it becomes difficult for the foreign matter 2 to adhere to the inner wall of the processing chamber 3 during the semiconductor manufacturing process.

A second embodiment of the present invention will be described with reference to FIG. FIG. 2 is a schematic view of the plasma processing apparatus showing the second embodiment. In FIG.
The difference from FIG. 1 is that the cleaning liquid inlet 10, the cleaning liquid outlet 11, the inlet shutter 12, the outlet shutter 13, the air inlet shutter 14, the exhaust outlet shutter 1 are provided on the wall of the processing chamber 3.
5 is provided, and other points are the same as in the first embodiment.

The cleaning device of this embodiment has a cleaning liquid inlet 1
0 and a cleaning liquid outlet 11, an ultrasonic oscillator 1 provided in the processing chamber 3 for ultrasonically vibrating the foreign substance 2 adhering to the inner surface of the processing chamber 3, and a cleaning liquid inlet 1.
0 and a cleaning liquid supply / discharge device (not shown) for supplying / discharging the cleaning liquid to / from the processing chamber 3 through the cleaning liquid discharge port 11.

As the cleaning liquid, water, ethyl alcohol, acetone or a mixed liquid thereof is used. The operation of this cleaning device will be described. Normally, when the inner wall of the processing chamber 3 is not cleaned, both the air supply port shutter 14 and the exhaust port shutter 15 are open for the plasma processing operation, and the vacuum device 6 is operating. In addition, the inlet shutter 12 and the outlet shutter 13
Is closed and the ultrasonic oscillator 1 is stopped.

When cleaning the processing chamber 3, first, the vacuum device 6 is stopped and both the air supply port shutter 14 and the exhaust port shutter 15 are closed. Inlet shutter 1
2 is opened, the cleaning liquid is introduced from the cleaning liquid introducing port 10, and the inside of the processing chamber 3 is filled with the cleaning liquid. Next, the inlet shutter 12 is closed, the ultrasonic oscillator 1 is operated, and the foreign matter 2 attached to the inner wall of the plasma processing apparatus 3 is peeled off. Then
The ultrasonic oscillating device 1 is stopped, the discharge port shutter 13 is opened, and the cleaning liquid is discharged from the cleaning liquid discharge port 11 together with the separated foreign matter 2. Finally, the outlet shutter 13 is closed, and the cleaning of the inner wall of the processing chamber 3 is completed.

In the second embodiment, the inlet shutter 12, the outlet shutter 13, the inlet shutter 14 and the outlet shutter 15 are all provided in the processing chamber 3.
Needless to say, the specification may be such that the cleaning liquid is completely shut off so that the cleaning liquid does not leak to the outside. According to the second embodiment, the foreign matter 2 can be removed to the outside of the processing chamber 3 without opening the inside of the processing chamber 3 to the atmosphere as in the conventional case.
There are the same effects as those of the first embodiment. Further, in the second embodiment, when the cleaning liquid supply / discharge device is configured so that the cleaning liquid circulates in the processing chamber 3 and foreign matter separating means (not shown) such as a foreign matter separation filter for the cleaning fluid is provided, the cleaning liquid is circulated. By setting the pressure of the pump for use, foreign matter can be removed efficiently and cleaning liquid can be saved.

Further, if a heater (not shown) is provided in the processing chamber 3, it becomes difficult for the foreign matter 2 to adhere to the inner wall of the processing chamber 3 during the plasma processing operation of the processing chamber 3, and it remains when cleaning with a cleaning liquid. The remaining cleaning liquid can be removed in a short time because the cleaning liquid thus formed can be vaporized. A third embodiment of the present invention will be described with reference to FIG. That is,
FIG. 3 is a schematic view of the plasma processing apparatus showing the third embodiment.

In FIG. 3, 16 is a light source, 17 is a laser beam, 18 is a first measurement window, 19 is a second measurement window, and 20.
Is a light receiving unit, 21 is a recording device, and other configurations are the first
It is similar to the embodiment of. This cleaning device according to the first embodiment has a light source 16 and a light receiving section 20 for receiving the light source 16, and a processing chamber 3 is arranged between the light source 16 and the light receiving section 20 so that the light from the light source 16 is processed. Measurement windows 18 and 19 that pass through the chamber 3 are provided in the processing chamber 3. The light receiving unit 20 converts the intensity of light into an electric signal and records it in the recording device 21.

The operation of the third embodiment will be described. Light source 16
The laser beam 17 emitted by the laser beam 17 passes through the first measurement window 18 provided at one end of the processing chamber 3 and the first measurement window 18
The intensity of the laser beam 17 that reaches the light receiver 20 after passing through the second measurement window 19 provided at a position opposed to is recorded in the recording device 21. Figure 4
FIG. 3 is a correlation diagram showing the discharge time of the cleaning gas plasma, that is, the cleaning time, and the intensity of the laser beam received by the light receiving unit 20, and the state before cleaning is the first measurement window 1;
Since the foreign matter 2 adheres to the inner wall of the second measurement window 8 and the second measurement window 19, the laser beam reaching the light receiving portion 20 is absorbed by the foreign matter 2 and its intensity is low, but the film of the foreign matter 2 progresses as cleaning proceeds. Since the thickness decreases, the intensity of the laser beam reaching the light receiving unit 20 increases. Therefore, by detecting the maximum value of the intensity with the light receiving unit 20, it is possible to set the cleaning end point.

As described above, according to the third embodiment, the foreign matter 2 attached to the inner surfaces of the measurement windows 18 and 19 as the cleaning progresses.
Are eliminated, the intensity of the light received by the light receiving unit 20 increases, and it is possible to detect that the cleaning is completed at the point where the intensity becomes maximum, and the end point of the cleaning can be clearly defined. can do. Although the laser light is used as the light source 16, the invention is not limited to this, and the film thickness of the foreign matter 2 attached to the measurement windows 18 and 19 may be measured by the intensity of light. Further, although the third embodiment is applied to the first embodiment, it may be applied to the second embodiment.

The cleaning method of the plasma processing apparatus according to the fourth embodiment of the present invention is to operate the ultrasonic oscillator during the semiconductor manufacturing process, that is, at the same time as the plasma processing operation. Similar effects can be obtained.

[0035]

According to the cleaning apparatus of the plasma processing apparatus of the first aspect, when the ultrasonic wave oscillating apparatus is operated, the foreign matter adhered to the inner surface of the processing chamber is detached from the inner surface by the ultrasonic vibration.
Since it is exhausted to the outside of the processing chamber by the exhaust means, foreign matter in the processing chamber is not affected by the gas flow path inside the processing chamber or the structure inside the processing chamber as in the conventional case, and the attachment / detachment of internal parts is not required. There is an effect that can be effectively exhausted.

According to a second aspect of the cleaning apparatus of the plasma processing apparatus of the present invention, in the first aspect, the foreign matter exhausting means is a vacuum device, and the degree of vacuum in the processing chamber is maintained in a reduced pressure state.
Since the ultrasonic oscillator is operated, in addition to the effect of the first aspect, the polymer and reaction products attached to the inner wall of the processing chamber are peeled off at the stage of growing into a foreign substance, and the adhesion of particles to the wafer is reduced. Further, even if the separated foreign matter adheres to the inner wall of the processing chamber, the foreign matter is desorbed by the ultrasonic vibration, so that the foreign matter does not stay in the processing chamber for a long time.

According to the cleaning device of the plasma processing apparatus of claim 3, in claim 1 or 2, the cleaning gas supply means for constantly supplying the cleaning gas into the processing chamber at a constant flow rate is provided. In addition to the effect of, foreign matter can be completely exhausted. According to the cleaning device of the plasma processing apparatus of claim 4, in claim 3, since the cleaning gas is an inert gas, the same effect as in claim 3 is obtained.

According to the cleaning device of the plasma processing apparatus of the fifth aspect, in addition to the effect of the first aspect, the processing chamber filled with the cleaning liquid is ultrasonically vibrated to remove foreign matters and discharge the cleaning liquid. It is possible to remove foreign substances to the outside of the processing chamber without exposing the inside of the processing chamber to the atmosphere as in the conventional case. According to the cleaning device of the plasma processing apparatus of claim 6, in claim 5, the cleaning liquid supplying / discharging device circulates the cleaning liquid in the processing chamber and has a foreign matter separating means for the cleaning liquid. Besides, foreign matter can be removed efficiently and cleaning liquid can be saved.

According to the cleaning device of the plasma processing apparatus of claim 7, in claim 5 or 6, the cleaning liquid is water, ethyl alcohol or acetone, or a mixture thereof. Has the same effect as. According to the cleaning device of the plasma processing apparatus of claim 8, in any one of claims 1 to 7,
Since the heater is provided in the processing chamber, in addition to the effects of various claims, foreign substances are less likely to adhere to the inner wall of the processing chamber during plasma processing operation of the processing chamber, and cleaning liquid remaining when cleaning with cleaning liquid is performed. Since it can be vaporized, the residual cleaning liquid can be eliminated in a short time.

According to a ninth aspect of the present invention, there is provided a cleaning device for a plasma processing apparatus according to any one of the first to eighth aspects, which has a light source and a light receiving section for receiving light from the light source.
Since the processing chamber is arranged between the light source and the light receiving section, and the measuring window through which the light from the light source can pass through the processing chamber is provided, the effects of the various claims are obtained, and the inner surface of the measuring window is improved as the cleaning progresses. Since the foreign matter adhering to the will be removed, the intensity of the light received by the light receiving part will increase, and it will be possible to detect that the cleaning is completed at the point where the intensity reaches its maximum.
The end point of cleaning can be clarified.

According to the cleaning method of the plasma processing apparatus of the tenth aspect, the plasma oscillating operation of the processing chamber is performed, and at the same time, the ultrasonic oscillating apparatus is operated.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a plasma processing apparatus having a cleaning device according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram of a plasma processing apparatus having a cleaning device according to a second embodiment of the present invention.

FIG. 3 is a schematic diagram of a plasma processing apparatus having a cleaning device according to a third embodiment of the present invention.

FIG. 4 is a correlation diagram between the cleaning time and the intensity of laser light in the third embodiment.

FIG. 5 is a schematic diagram of a conventional plasma processing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ultrasonic oscillator 2 Foreign matter 3 Processing chamber 6 Vacuum device as exhaust means

Claims (10)

[Claims] 1. A processing chamber, an ultrasonic oscillator provided in the processing chamber for ultrasonically oscillating foreign matter adhering to the inner surface of the processing chamber to remove the foreign matter, and an exhaust means for exhausting the foreign matter. Cleaning equipment for plasma processing equipment. 2. The plasma processing according to claim 1, wherein the means for exhausting foreign matter is a vacuum device, and the ultrasonic oscillator can be operated in a state where the degree of vacuum in the processing chamber is maintained in a reduced pressure state. Equipment cleaning device. 3. The cleaning device for a plasma apparatus according to claim 1, further comprising a cleaning gas supply unit that constantly supplies the cleaning gas into the processing chamber at a constant flow rate. 4. The cleaning gas is an inert gas.
A cleaning device for a plasma processing apparatus according to. 5. A processing chamber having a cleaning liquid inlet and a cleaning liquid outlet, and an ultrasonic oscillator provided in the processing chamber for ultrasonically vibrating foreign matter adhering to the inner surface of the processing chamber.
A cleaning device for a plasma processing apparatus, comprising: a cleaning liquid supply / discharge device for supplying / discharging the cleaning liquid to / from the processing chamber through the cleaning liquid inlet and the cleaning liquid outlet. 6. The cleaning device for a plasma processing apparatus according to claim 5, wherein the cleaning liquid supply / discharge device circulates the cleaning liquid in the processing chamber and has foreign matter separating means for the cleaning liquid. 7. The cleaning device for a plasma processing apparatus according to claim 5, wherein the cleaning liquid is water, ethyl alcohol, acetone, or a mixed liquid thereof. 8. The cleaning device for a plasma processing apparatus according to claim 1, wherein a heater is provided in the processing chamber. 9. A measurement window having a light source and a light receiving section for receiving the light of the light source, a processing chamber being arranged between the light source and the light receiving section, and a measurement window for allowing the light of the light source to pass through the processing chamber. The cleaning apparatus for a plasma processing apparatus according to claim 1, wherein the cleaning apparatus is provided in the processing chamber. 10. A method of cleaning a plasma processing apparatus, comprising simultaneously operating a plasma processing operation of a processing chamber and operating an ultrasonic oscillator.