JPH0821573B2 - Plasma processing device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a plasma processing apparatus, and more particularly to a plasma processing apparatus suitable for improving the reliability of plasma emission analysis during plasma processing.

[Conventional technology]

Conventionally, as disclosed in, for example, Japanese Patent Laid-Open No. 57-120674, a method is known in which an emission spectrum of a substance to be etched is taken out during etching to detect the progress of etching. This takes in the emission spectrum from the window provided in the etching tank and detects it through a spectroscope, a photodetector, an amplifier and a recorder.

[Problems to be solved by the invention]

In the above conventional technique, an adhesive reaction product is generated depending on the type of processing gas used for processing, an etching material, discharge conditions for plasma generation, and this is used as an emission spectrum, that is, a window for taking in plasma light. No consideration has been given to the fact that the amount of plasma light that has adhered adheres to the surface and decreases, which hinders the progress of etching from being detected, and there is a problem in ensuring the reliability of the etching apparatus.

An object of the present invention is to provide a plasma processing apparatus capable of preventing the reaction products from adhering to the plasma light collecting section and improving the reliability of monitoring the processing status in the plasma processing.

[Means for solving problems]

The above-described object is to provide a processing chamber in which a processing gas is supplied and which is evacuated to a predetermined pressure, a plasma generating means for generating plasma in the processing chamber, and a plasma emission detection for detecting light emission of plasma generated by the plasma generating means. In the plasma processing apparatus having means, a light collection hole provided so as to communicate with the processing chamber as a plasma light collection section, and a plasma light emission reception section of the plasma light emission detection section provided so as to communicate with the light collection hole. A vacuum provided between the plasma light emitting / receiving unit and a gas supply passage provided so as to flow the processing gas, a portion connecting the gas supply passage and a tube having the lighting hole, and the plasma emission light receiving unit. This is achieved by including a valve and a heating unit provided so as to heat the periphery of the plasma light emitting / receiving unit.

[Operation] A gas flow toward the processing chamber is formed in the plasma light collecting portion, in other words, a light collecting portion is provided in the gas supply path, and the reaction generation generated in the processing chamber by the gas flow is formed. It is possible to prevent objects from flying and adhering, and prevent contamination of the lighting part. Furthermore, the effect of preventing the adhesion reaction product from adhering to the quartz fiber can be further enhanced by heating the plasma light collecting portion.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG.

FIG. 1 shows a magnetic field microwave plasma etching apparatus in this case. The processing chamber 13 is composed of a chamber 2 in which a sample stage 3 is installed and a discharge tube 1 made of quartz or alumina. A waveguide 7 having a magnetron 6 attached to an end thereof is provided on the processing chamber 13, and the side of the processing chamber 13 is provided with the discharge tube 1
A magnetic field coil 8 is provided via a waveguide 7 further covered with. The lower part of the chamber 2 is connected to an exhaust device (not shown), and a side of the chamber 2 is provided with a lighting hole 14 as shown in FIG. The pipe 5 is not connected. In this case, the gas supply pipe 5 is connected to a gas supply device (not shown). The quartz fiber 9 is connected to the emission analysis device 10 and constitutes plasma emission detection means.

With the above configuration, the sample 4 is placed on the sample table 3 and the processing chamber
A process gas is introduced into the inside of the processing chamber 13 from the gas supply pipe 5, and the pressure inside the processing chamber 13 is reduced and exhausted to a predetermined value and maintained, and the microwave from the magnetron 6 is applied to this through the waveguide 7, and the magnetic field When the magnetic field is applied by the coil 8, the process gas is turned into plasma by the synergistic effect of the microwave and the magnetic field to etch the sample, and the intensity of the specific wavelength during plasma emission is during the etching of the sample and after the etching is completed. Taking advantage of the fact that it changes with, the plasma emission is taken in through the quartz fiber 9 from the light collecting hole 14 which is the light collecting portion, and analyzed by the light emission analyzer 10 to determine the etching end point.

At this time, as shown in FIG.
The quartz fiber 9 straightly provided in 14 enters without interruption in the middle, and in this case, the process gas is supplied from the gas supply pipe 5 provided at right angles to the lighting hole 14 to the lighting hole 14 It is sent into the processing chamber 13 via.

As described above, according to this embodiment, since the process gas flows toward the reaction chamber in the lighting hole 14 between the quartz fiber 9 and the processing chamber 13, the adhesive reaction product is generated by the quartz fiber 9
Can be prevented, and contamination of the quartz fiber 9 can be prevented.

In the present embodiment, the process gas was flowed through the daylighting hole 14, but if the gas does not affect the process characteristics of the plasma treatment, this gas is flown through the daylighting hole 14 and the process gas is supplied through another introduction path. It may be supplied from.

Next, a second embodiment will be described with reference to FIG. In this figure, the same reference numerals as those in FIG.
The difference from the figure is that a heater 11 is attached to the portion of the quartz fiber 9 for heating. As a result, the effect similar to that of the above-described embodiment can be obtained, and the effect of preventing the adhesion reaction product from adhering to the quartz fiber 9 can be further enhanced by this heating.

Further, a third embodiment will be described with reference to FIG. In this figure, the same reference numerals as in FIG. 2 indicate the same members, and the difference of this figure from FIG. 2 is that a vacuum valve 12 is provided between the gas pipe 5 and the quartz fiber 9. According to this embodiment, the same effect as that of the first embodiment is obtained, and even if the quartz fiber 9 is contaminated by the attached reaction product and needs to be cleaned, the quartz fiber 9 is closed after the valve 12 is closed. Once pulled out, the entire reaction chamber can be maintained without leaking to the atmospheric pressure, so that the maintenance time of the apparatus can be shortened.

In this case, it is better to install a leak pipe and / or an exhaust pipe between the valve 12 and the quartz fiber 9.
In addition, the valve 12 in this case is of course of a type that allows the interior of the reaction chamber to be seen through the quartz fiber 9 in the open state.

In the embodiments described above, the magnetic field microwave etching apparatus is taken as the etching apparatus, but the object of the present invention is not limited to this type of etching apparatus.

Further, as the plasma light emitting / receiving unit, the quartz fiber is taken as an example in the present embodiment, but this is not limited to the quartz fiber alone.

Further, the scope of application of the present invention is not limited to the etching apparatus, but can be applied to all apparatuses that generate plasma and observe the light emission thereof.

[Advantages of the Invention] According to the present invention, it is possible to prevent the reaction products from adhering to the plasma light collecting portion, and thus it is possible to improve the reliability of monitoring the processing status in the plasma processing.

[Brief description of drawings]

1 is a longitudinal sectional view showing a plasma processing apparatus according to an embodiment of the present invention, FIG. 2 is a detailed view of a portion A of FIG. 1, and FIG. 3 is a detailed view of a second embodiment of FIG. 4 and 5 are detailed views showing the third embodiment of FIG. 5 ... Gas supply pipe, 9 ... Quartz fiber, 10 ... Emission analyzer, 13 ... Processing chamber, 14 ... Lighting hole

Claims (1)

[Claims] 1. A processing chamber to which a processing gas is supplied and which is evacuated to a predetermined pressure and evacuated, plasma generating means for generating plasma in the processing chamber, and plasma emission for detecting emission of plasma generated by the plasma generating means. In a plasma processing apparatus having a detection means, a lighting hole provided so as to communicate with the inside of the processing chamber as a lighting portion for the plasma light, and a plasma light emission receiving portion of the plasma light emission detection means provided so as to communicate with the lighting hole. In the previous stage, between the plasma light emitting / receiving unit and the gas supply passage provided so as to flow the processing gas, and the portion connecting the gas supply passage and the tube having the lighting hole. A plasma processing apparatus comprising: a vacuum valve; and a heating unit provided to heat the periphery of the plasma light emitting / receiving unit.