JPH03222416A - Plasma etching device - Google Patents

Abstract

PURPOSE:To make it possible to obtain equalized plasma under the control of a gas flow by a straightening vane capable of vertically moving into an upper electrode. CONSTITUTION:A gas straightening vane 6 is installed into an upper electrode 1. After a sample 7 is placed on a lower electrode 3 and gas is adapted to flow into a chamber 1 from a gas intake port 4 and a specified gas pressure is maintained, high frequency electric power is supplied between the upper electrode 2 and the lower electrode 3 from a high frequency power source so that the surface of the sample 7 may be etched by generating gas plasma. At that time, the direction of gas flow is changed by moving up and down the gas straightening vane 6 in the upper electrode 2 so that the optimum gas flow to the space between the upper electrode 2 and the lower electrode 3 amy be produced. It is, therefore, possible to obtain equalized plasma.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a plasma etching apparatus for applying plasma etching to a semiconductor substrate or the like.

[Prior art 1] Figure 3 shows a conventional parallel plate type plasma etching apparatus, in which an upper electrode (2) and a lower electrode (3) which also serves as a sample stage are arranged in a chamber (1). The temperature inside the chamber (1) is 10 Torr to 10-5 To
After that, an etching gas such as SF6 is introduced into the gas inlet (4) and maintained at a predetermined pressure, and a high frequency power source (8) is connected between the picture electrodes (2) and (3).
) to generate gas plasma by supplying high-frequency power to a sample (such as a semiconductor substrate) placed on the lower electrode (3).
a) Etching the surface. (5) is a gas exhaust port.

[Problems to be Solved by the Invention] In the conventional plasma etching apparatus as described above, after gas is introduced, the flow of gas within the chamber depends on the distance between the upper electrode and the lower electrode, the gas flow rate, and the position of the gas exhaust port. However, after the position of the upper electrode, gas flow rate, etc. are optimized in order to obtain an anomalous etching characteristic, there is no means to correct the plasma distribution affected by the gas flow.

Because the flow of gas cannot be controlled in this way,
There was a problem in that it was difficult to obtain uniform plasma.

The present invention was made to solve the above problems, and an object of the present invention is to provide a plasma etching apparatus that can control the flow of gas and obtain uniform plasma.

[Means for Solving the Problems 1] In the plasma etching apparatus according to the present invention, at least one rectifying plate that is movable up and down is provided inside the upper electrode.

[Function] In this invention, the flow of gas is controlled by the rectifier plate inside the upper electrode.

[Embodiment] FIG. 1 shows an embodiment of the present invention, in which a gas rectifying plate (6) is provided inside the upper electrode (1). Otherwise, the same reference numerals as in FIG. 3 indicate the same parts.

With the above configuration, the sample (7) is placed on the lower electrode (3), gas is flowed into the chamber (1) from the gas inlet (4), and after maintaining it at a predetermined pressure, the sample (7) is placed on the lower electrode (3). A high frequency power source (8) supplies high frequency power between the lower electrode (3) and the lower electrode (3) to generate gas plasma and etch the surface of the sample (A). At that time, by moving the gas rectifier plate (6) in the upper mold fi (2) up and down, the gas flow changes and the optimal flow into the space between the upper electrode (2) and the lower electrode (3) is achieved. A gas flow can be created and a uniform plasma can be obtained.

For example, when the gas baffle plate (6) is moved upward, the gas flow is concentrated in the center of the electrode, and conversely, when the gas baffle plate (6) is moved downward, the gas flow is spread outward.

As a result, the way the plasma spreads changes.

In the above embodiment, the high frequency power is supplied to the upper electrode (2), but even if the high frequency power is supplied to the lower electrode (3), the same effect as in the above embodiment can be obtained.

In addition, although the rectifier plate (6) was used only for gas rectification,
In Figure 2, ions in the plasma reaching the surface of the sample (7) are reduced by supplying high-frequency power between the electrode (6) and the lower electrode (3) using the rectifying plate (6) as an electrode. , plasma etching can be performed with less damage to the sample substrate.

Furthermore, a plurality of current plates may be provided.

[Effects of the Invention] As described above, according to the present invention, uniform plasma can be obtained by controlling the flow of gas using the rectifying plate provided in the upper electrode.

[Brief explanation of drawings]

FIG. 1 is a sectional view of one embodiment of the present invention, FIG. 2 is a sectional view of another embodiment, and FIG. 3 is a sectional view of a conventional plasma etching apparatus. (1)...Chamber, (2)...Top electrode, (3)
...Lower electrode and sample stage, (4)...Gas inlet, (
5)...Gas exhaust port, (6)...Cass rectifier plate (or electric Vi), (7)...Sample, (8)...High frequency power source. Note that in each figure, the same reference numerals indicate the same parts. (1) The description is corrected as follows. Procedural amendment August 6, 1990

Claims (1)

[Claims] In a plasma etching apparatus, a sample stage electrode and its counter electrode are provided in an etching chamber, and a process gas is introduced through the interior of the counter electrode. A plasma etching apparatus characterized by comprising a rectifying plate that controls the flow of the plasma.