JPS60218846A - Dry etching apparatus - Google Patents

Abstract

PURPOSE:To prevent a reaction product or the like from adhering on a light- transmitting plate of a light-transmitting window and to enable the detection or radiation of light to be performed with good reproducibility, by interposing a cooling trap between the light-transmitting plate and the reaction chamber. CONSTITUTION:When etching is carried out in a reaction chamber consisting of a vacuum container 11, any reaction product or the like produced thereby is adsorbed, before it reaches the inner face of a light-transmitting plate (glass) 13, by a cooling trap 14 in which cooling fluid flows and which is provided midway to a light-transmitting window 12, so that the inner face of the light-transmitting plate 13 is not contaminated by such a product. Accordingly, the light transmittance of the plate 13 is maintained constant, and therefore detection or radiation of light can be carried out stably. In the end point detection by spectro-chemical analysis, the end point spectral strength is maintained constant thereby the end point detection is enabled to be performed with good reproducibility and high reliability.

Description

[Detailed description of the invention] Industrial applications This invention relates to a dry etching device.

Structure of the conventional example and its problems In the conventional dry etching apparatus, as shown in the concrete structure in FIG. An exhaust means is connected through an exhaust port 3, and inside the vacuum container 1, an upper electrode 4 and a lower electrode 6 which also serves as a support for a sample 6 are provided, and a reaction chamber 7 is formed between the two electrodes.
A high frequency power source 8 is connected to either one of the electrodes 4.6, and plasma light is transmitted to the plasma etching the sample 6 through a transparent plate (glass) 10 provided in a transparent window 9. can be used to monitor the etching process by spectroscopic analysis, to detect the end point, or to detect the etching process using a transparent plate (
By irradiating the plasma and the sample 6 with light through the glass 1o, the plasma state and the state of each surface of the sample 6 were changed to improve the etching characteristics.

However, in the above configuration, reaction products etc. generated when etching the sample 5 are transferred to the transparent plate (glass) 10.
As a result, the light transmittance of the light-transmitting plate (glass) 1o becomes unstable and decreases.For example, when detecting light and performing spectroscopic analysis to detect the end point of etching, or when irradiating light. When improving the etching mechanism, good reproducibility could not be obtained, and the etching apparatus had the drawback of lacking reliability.

Purpose of the Invention The purpose of the present invention is to prevent reaction products generated during etching from adhering to the transparent plate of the transparent window, and to enable light detection and light irradiation through the transparent plate with good reproducibility. It is an object of the present invention to provide a dry etching device that allows for dry etching.

Structure of the Invention The dry etching apparatus of the present invention includes a cooling trap,
It is characterized by being inserted between the light-transmitting plate and the reaction chamber, and has the effect of preventing reaction products from adhering to the surface of the light-transmitting plate and reducing the light transmittance and making it unstable.

DESCRIPTION OF THE EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. 2 to 4. FIG. 2 is a perspective view of essential parts of the dry etching apparatus. Reference numeral 11 denotes a vacuum container, and a processing gas supply means and an exhaust means (not shown) are connected to the outside of the vacuum container 11. Also, an upper electrode and a lower electrode (not shown) are provided inside the vacuum container 11, and both By connecting a high frequency power source (not shown) to either one of the electrodes, an etching reaction chamber for a sample placed on the lower electrode is created between the two electrodes. 12 is a transparent window provided in a part of the vacuum container 11, 13 is a transparent plate (glass), and 14 is a cooling trap made of, for example, a stainless steel pipe, through which a cooling liquid cooled by a cooling means (not shown) flows. . When etching is carried out in the reaction chamber, the reaction products generated are
Before reaching the inner surface of the light-transmitting plate (glass) 13, it is adsorbed by the cooling trap 14 provided halfway through the light-transmitting window 12, so that the inner surface of the light-transmitting plate (glass) 13 is not contaminated. Therefore, according to this embodiment, the light transmittance of the transparent plate (glass) 13 is kept constant, so that light detection and irradiation can be performed stably and with good reproducibility. For example, when detecting the end point by spectroscopic analysis, in the conventional configuration, as shown in FIG. The spectral intensity at the etching end point decreases as the etching ends (see curve). However, according to this embodiment, as shown in FIG. )13 There is almost no deposit on the inner surface,
Therefore, the spectral intensity at the end point is kept constant during continuous etching (see curve B), making it possible to detect the end point with good reproducibility and high reliability. However, the third and fourth
In the figure, the processing gas o
014. Gas flow rate 20 SCCM, vacuum degree 0.10T
Orr.

The high frequency power supply power is 120W. In Figure 3, T
, l T21 T31 ''41 T5 indicates the etching time for each sample.

FIG. 6 is a perspective view of a main part of a dry etching apparatus according to a second embodiment of the present invention. 11 is a vacuum container, 12 is a transparent window, 13 is a transparent plate (glass), and 14 is a cooling trap made of, for example, stainless steel.The difference from FIG. 2 is the shape of the cooling trap 14. The cooling trap 14 of this embodiment has a hollow hole in the center through which light passes, and a cooling water flow path inside the outer wall. Before reaching the inner surface, it is adsorbed on the large hollow surface of the cooling trap 14.

FIG. 6 is a sectional view of a main part of a dry etching apparatus according to a third embodiment of the present invention. 11 is a vacuum container, 12 is a transparent window, 13 is a transparent plate (glass), and 14 is a cooling trap made of, for example, stainless steel.The difference from FIG. It increases the area and makes the adsorption of reaction products more effective.

In addition, the above 1. In the second and third embodiments, the cooling trap 14 is configured so that a cooling liquid can flow therein, but instead of the cooling liquid, a cooling gas may be allowed to flow therein.

Alternatively, the cooling trap 14 may be filled with liquid nitrogen, for example.

Effects of the Invention According to the dry etching apparatus of the present invention, the effect of highly reliable etching can be obtained by improving the reproducibility of light detection, light irradiation, etc. performed through the transparent plate.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view of a conventional dry etching apparatus, FIG. 2 is a perspective view of essential parts of the first embodiment of the present invention, FIG. 3 is a spectrum intensity diagram for detecting the end point of etching in the conventional example, and FIG. 4 is a spectrum intensity diagram for detecting the end point of etching in the first embodiment. FIG. 6 is a perspective view of the main part of the second embodiment, and FIG. 6 is a sectional view of the main part of the third embodiment. 4.6... Electrode, 7... Reaction chamber, 8.
...High frequency power supply, 11...Vacuum container, 1
2...Transparent window, 13...Transparent plate (glass), 14...Cooling trap. Name of agent: Patent attorney Toshio Tsuchinakao line or one person Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] A vacuum container, a processing gas supply means connected to the vacuum container, an exhaust means connected to the vacuum container, a pair of electrodes for generating zirazma that are arranged opposite to each other in the vacuum container, and a high frequency voltage between these electrodes. a high-frequency power supply for applying a high frequency power, a light-transmitting window provided in the vacuum container and having a light-transmitting plate for extracting plasma light from the reaction chamber between the two electrodes, and a light-transmitting window disposed on the reaction chamber side of the light-transmitting plate. A dry etching device equipped with a cooling trap to prevent reaction components from adhering to the transparent plate.