JPS61174388A - Etching device - Google Patents

Abstract

PURPOSE:To remove the fluctuation of etching and to enhance the high accuracy and yield of a pattern by providing many gas discharging ports which can control the gas discharging quantity among gas introducing ports of an upper electrode. CONSTITUTION:The upper electrode 2 and lower electrode 3 are disposed facing each other in a chamber 1 where a prescribed degree of vacuum is kept, a wafer 4 is transported onto the lower electrode 3, and the etching is carried out by the gas which is converted into plasma by high-frequency voltage impressed on the upper electrode 2 or lower electrode 3 in the conditions where a constant atmosphere is kept by the introducing and exhausting of the gas. Many gas discharging ports 2a and gas introducing ports 2b for the upper electrode 2, and many gas discharging ports 3a for the lower electrode 3 are provided respectively. The discharging quantity of gas coming from gas discharging ports 2a, 3a is controlled by conductance variable valves 5, 6.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a dry etching apparatus for etching a semiconductor wafer in a semiconductor manufacturing process.

[Background of the invention]

In the manufacturing process of semiconductor wafers, etching uniformity is an extremely important factor for improving product yield. A factor that affects the uniformity of etching is the flow of process gas.

The conventional etching device is [Electronic Materials J (March 1983)
As described on page 3 of the special feature article titled "Recent Ultra-L8I Technology and Manufacturing Equipment" in the Monthly issue (published by Kogyo Research Association), gas is is introduced to form a shower, and is exhausted from a number of exhaust ports provided on the outer periphery of the wafer of the lower electrode (opposing anode).

However, with this structure, the exhaust port is provided at the outer periphery of the wafer, so the gas flow becomes uneven between the center of the wafer and the outer periphery of the wafer, resulting in variations in etching within the wafer. There was a problem.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide an etching apparatus that can eliminate etching fluctuations, improve pattern precision, and improve yield.

[Summary of the invention]

In order to achieve the above object, the present invention provides an etching apparatus in which a pair of upper and lower electrodes are disposed facing each other in a chamber, and the upper electrode is provided with a large number of gas inlets.
A large number of gas exhaust ports are provided between the gas inlet ports of the upper electrode, so that not only the gas introduction at the inner and outer periphery of the wafer, but also the gas exhaust can be controlled, thereby making it possible to equalize the etching speed on the wafer. Characteristics.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIG. 1. Inside a chamber 1 maintained at a predetermined degree of vacuum, an upper electrode 2 and a lower electrode 3 are disposed facing each other. wafer 4
is transferred onto the lower electrode 3, and while the inside of the chamber 1 is maintained at a constant atmosphere by gas introduction and exhaust, it is etched by the gas turned into plasma by the high-frequency voltage applied to the upper electrode 2 or the lower electrode 3. Ru.

The upper electrode 2 has a gas exhaust port 2a and a gas inlet port 2b.
are provided in large numbers, and the lower electrode 3 is provided with a large number of gas exhaust ports 3a. Therefore, the inside of the chamber 1 is controlled by the gas exhaust ports 2a and 3a.
, 3a are each evacuated with the displacement amount controlled by a variable conductance valve 5.6. Further, the process gas is introduced from a plurality of gas introduction pipes 7, and its flow rate is controlled by a mass flow controller 8, respectively, and the gas introduction port 2
It is introduced into the chamber 1 from b.

FIG. 2 shows the arrangement of the gas exhaust port 2a and gas inlet port 2b provided with the upper electrode 21. Here, the gas exhaust port 2a
is shown by a black circle, and the gas inlet 2b is shown by a white circle. In FIG. 1a), gas exhaust ports 2a and gas inlet ports 2b are randomly arranged. +bl in the figure is formed by alternately arranging gas exhaust ports 2a and gas inlet ports 2b concentrically. In the same figure (C), the gas exhaust port 2a and the gas inlet port 2b are arranged by being divided at an angle. In the figure (d), the gas exhaust port 2a and the gas inlet port 2b are arranged by dividing into slices.

In this way, a large number of gas exhaust ports 2a are provided between the gas inlet ports 2b of the upper electrode 2, and the gas inflow and gas exhaust amounts of the inner and outer peripheral portions of the wafer 4 can be controlled respectively. The film to be etched within the wafer 4 can be easily controlled without being affected by the opening 3a.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, the gas flow rate and gas exhaust amount at the inner and outer peripheries of the wafer can be controlled respectively, so that the etching speed at the inner and outer peripheries of the wafer can be maintained constant. be able to. Therefore, differences in etching conditions due to differences in the film to be etched can be easily dealt with, uniform etching can be achieved, and pattern precision and yield can be improved.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the etching apparatus according to the present invention, and FIGS. 2(a) and 2(b) (c) and (d) are layout diagrams of the gas exhaust port and gas inlet port of the upper electrode. 1... Chamber, 2... Upper electrode, 2a
...Gas exhaust port, 2b...Gas inlet port, 3.
...Lower electrode. -, Figure 2

Claims (1)

[Claims] In an etching apparatus in which a pair of upper and lower electrodes are arranged facing each other in a chamber, and the upper electrode is provided with a large number of gas inlets, a large number of gases whose exhaust amount can be controlled are provided between the gas inlets of the upper electrode. An etching device characterized by having an exhaust port.