Plasma etching apparatus

Abstract

In order to improve a controllability of etching characteristics by way of precisely and freely controlling a flow or a density distribution of a processing gas introduced into a processing chamber, a plasma etching apparatus includes, as a gas inlet for introducing an etching gas into a plasma generation region PS in a chamber 10, an upper gas inlet (an upper central shower head 66a and an upper peripheral shower head 68a) for introducing a gas through an upper electrode 38; and a side gas inlet for introducing a gas through a sidewall of the chamber 10. The side gas inlet 104 has a side shower head 108 attached to the sidewall of the chamber 10.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a plasma etching apparatus; and, more particularly, to a parallel plate plasma etching apparatus. BACKGROUND OF THE INVENTION [0002] A recent trend towards a miniaturized semiconductor device structure in design criteria intensifies a demand for processing a material to be etched in a cross sectional shape of a high-density pattern. Currently, in a plasma etching apparatus for use in manufacturing a semiconductor device or a flat panel display (FPD), a generation of high-density plasma is indispensable for a miniaturization of a semiconductor device structure or a high-rate etching process for a substrate to be processed (a semiconductor wafer, a glass substrate or the like). Accordingly, in a parallel plate plasma etching apparatus, in order to generate the high-density plasma, various investigations or trials have been attempted by way of increasing a frequency of a plasma exciting radio frequency RF from a conventiona...

AI Technical Summary

Benefits of technology

[0005] It is, therefore, an object of the present invention to provide a parallel plate plasma etching apparatus capable of improving a controllability of etching characteristics by way of precisely and freely controlling a flow or a density distribution of a processing gas introduced into a processing chamber.

[0007] In the first plasma etching apparatus, the first gas including etchant gas is introduced downward through the upper gas inlet into the plasma generation region between the upper electrode and the lower electrode and, at the same time, the second gas including dilution gas is introduced inwardly through the side gas inlet into the plasma generation region. In accordance with such gas introduction manner for introducing and mixing different etching gas species from two directions of the upper and the side portion, gas species, gas mixing ratios and gas flow rates of each system can be properly selected and adjusted and, further, a balance between both systems can be controlled. Accordingly, it is possible to precisely and freely control a flow or a density distribution of a processing gas in the plasma generation region, thereby improving a controllability of etching characteristics on a substrate.

[0014] In the second plasma etching apparatus, the first gas including dilution gas is introduced downward through the upper central gas inlet into the plasma generation region between the upper electrode and the lower electrode; the second gas including etchant gas is introduced downward through the upper peripheral gas inlet into the plasma generation region; and the third gas including dilution gas is introduced inwardly (toward the center) through the side gas inlet. In accordance with such gas introduction manner for introducing two gas species for etching from two directions, i.e., from above and side and mixing the first and the third gas including dilution gas respectively through the upper central gas inlet and the side gas inlet so that the second gas including etchant gas introduced through the upper peripheral gas inlet can be maintained between the central portion and the side portion, it is possible to precisely and freely control a flow or a density distribution of a processing gas in the plasma generation region. Accordingly, a controllability of etching characteristics on a substrate can be further enhanced.

[0020] In the third plasma etching apparatus, the first gas including dilution gas is introduced downward through the first upper gas inlet into the plasma generation region between the upper electrode and the lower electrode; the second gas including etchant gas is introduced downward through the second upper gas inlet into the plasma generation region; and the third gas including dilution gas is introduced downward through the third gas inlet into the plasma generation region. In accordance with such gas introduction manner for introducing and mixing the first and the third gas including dilution gas respectively through the first and the third upper gas inlet so that the second gas including etchant gas introduced through the second upper gas inlet located at a middle portion of the upper electrode in a diametric direction, can be maintained between the central portion and the peripheral portion, it is possible to precisely and freely control a flow or a density distribution of a processing gas in the plasma generation region. Accordingly, a controllability of etching characteristics on a substrate can be further improved.

[0025] In accordance with the plasma etching apparatus of the present invention, by the aforementioned configuration and operation, it is possible to precisely and freely control a flow or a density distribution of a processing gas introduced into a processing chamber, so that etching characteristics can be improved.

Problems solved by technology

However, in the conventional parallel plate plasma etching apparatus, it is difficult to realize uniform etching characteristics on a substrate to be processed and, further, it is hard to control etching characteristics, especially on a peripheral portion of the substrate.

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