Semiconductor integrated circuit arrangement fabrication method

Abstract

To realize etching with a high selection ratio and a high accuracy in fabrication of an LSI, the composition of dissociated species of a reaction gas is accurately controlled when dry-etching a thin film on a semiconductor substrate by causing an inert gas excited to a metastable state in a plasma and a flon gas to interact with each other and selectively obtaining desired dissociated species.

Description

[0001]This is a continuation application of U.S. Ser. No. 09 / 188,371, filed Nov. 10, 1998, now U.S. Pat. No. 5,962,347; which is a continuation application of U.S. Ser. No. 08 / 857,167, filed May 15, 1997, now U.S. Pat. No. 5,874,013; which is a File Wrapper Continuation of U.S. Ser. No. 08 / 472,459, filed Jun. 7, 1995, now abandoned.BACKGROUND OF THE INVENTION[0002]The present invention relates to the art of semiconductor integrated circuit arrangement fabrication, and particularly to an art for dry-etching a thin film on a semiconductor wafer by using radicals or ions in a plasma.[0003]A silicon oxide film which is a typical insulating film used to fabricate an LSI is normally processed by a dry-etching system (plasma etching system) using a plasma process.[0004]In the case of an etching process using a typical magneto-microwave plasma etching system, a vacuum chamber of the etching system comprising a reaction chamber (etching chamber) and a discharge chamber is first evacuated up ...

AI Technical Summary

Benefits of technology

[0011]In the case of an electronic device with a high integration level, it is possible to open a contact hole with a diameter of 0.5 μm or less and a high aspect ratio (hole depth / hole diameter) , and moreover etching with a high accuracy and a high selection ratio is necessary, while minimizing the etching amount of a base silicon film, silicon nitride film, or a multilayer film made of these films.

[0053]To improve the selection ratio, it is necessary to remove non-selective dissociated species. Moreover, to keep the etching shape accuracy, it is necessary to use dissociated species having a selectivity and an adhesive property. From the properties in Table 2, it will be understood that the dissociated species in the row of non-selectivity are preferable. The etching rate can be obtained by ordinary system control such as controlling the introduced amount of reaction gases, mixing ratio of the reaction gases, and the power.

Problems solved by technology

However, it is difficult to realize this control by a conventional etching method using dissociation of reaction gas molecules caused by collision of electrons in a plasma.

This is because selective excitation by electrons can be realized only on antibonding orbitals of the minimum energy, but electrons with uniform energy necessary for realizing it cannot be obtained in a plasma.

In this case, however, the cost of the etching system greatly increases.

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