Plasma processing apparatus and a plasma processing method

Abstract

In an oxide film etching process, a plasma having a suitable ratio of CF3, CF2, CF, and F is necessary, and there is a problem in that the etching characteristic fluctuates in accordance with a temperature fluctuation of the etching chamber. Using a UHF type ECR plasma etching apparatus having a low electron temperature, a suitable dissociation can be obtained, and by maintaining the temperature of a side wall of the etching chamber in a range from 10° C. and 120° C., a stable etching characteristic can be obtained. Since oxide film etching using a low electron temperature and a high density plasma can be obtained, an etching result having a superior characteristic can be obtained, and, also, since the side wall temperature adjustment range is low, a simplified apparatus structure and a heat resistant performance countermeasure can be obtained easily.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a Continuation application of application Ser. No. 09 / 414,520, filed Oct. 8, 1999, the contents of which are incorporated herein by reference in their entirely.BACKGROUND OF THE INVENTION [0002] The present invention relates to a plasma processing apparatus and a plasma processing method and in particularly to an apparatus for etching an insulation film such as a silicon oxide film of a wafer using a plasma and relates to a plasma etching apparatus and a plasma etching method having a plasma generation source which can be corresponded to a minute practicing of an etching pattern and further enable for maintaining a stable etching characteristic during a long period. [0003] Among conventional plasma processing apparatuses, an oxide film plasma etching apparatus is exemplified and techniques and problems of this apparatus are shown. As the conventional plasma source of an oxide film use etching apparatus, a type which ...

AI Technical Summary

Benefits of technology

[0035] Herein, when the dissociation is excessive, F or C becomes rich, and when the dissociation is insufficient, there is a shortage of F, CF2, CF3, etc; accordingly, it is desirable to have a plasma dissociation fall in middle range. Further, since the side wall temperature is controlled to a low temperature, with a side wall temperature control accuracy of ±5° C., the fluctuation of the etching characteristic can be restrained for a long period of operation.

Problems solved by technology

Further, in the narrow electrode type plasma source, it is difficult to generate a plasma in a region where the pressure is low, however, by the addition of a magnetic field, an apparatus is obtained in which a lowering of the discharge pressure can be achieved.

For these reasons, in oxide film etching with a high electron temperature and a high density plasma, since the amount of CFx (CF3, CF2, CF) which adheres to a silicon surface, which is a foundation of the oxide film, is lowered, there are problems in that the etching-speed of the silicon (Si) is large and the selection ratio is small.

Since the scattering of the ion incident angle causes an abnormality of the etching shape and a decrease in the number of ions reaching the bottom of a deep hole, problems are caused including a lowering of the etching speed and a premature stopping of the etching in the formation of holes.

The influence of the affects of the reaction products which adhere to the side wall on the etching characteristic is discussed above, however, when the etching is continued over a long period of time, a change of the influence becomes a problem.

As a result, the temperature change of the side wall in the oxide film etching apparatus represents an important problem.

As stated above, in any of the plasma sources, to satisfy the requirement for oxide film etching, namely for obtaining a high etching speed, while attaining a high selection ratio, low micro loading, and the passing-through of a deep hole, there still remain problems to be solved.

The important problem in an oxide film etching apparatus involves the dissociation of the gas molecules as the plasma is being formed under the most suitable conditions for the etching of the oxide film.

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