Manufacture of semiconductor device

Abstract

Abstract PURPOSE:To form a pattern having a side of a tapered shape in dry-etching a film on a semiconductor substrate so as to obtain the desired pattern, by selecting the etching conductions, performing at first the isotropic etching, and thereafter performing anisotropic etching. CONSTITUTION:On a polycrystal silicon film 11 having the width of 5,000Angstrom , the pattern of a resist film 12 is formed. Then the isotropic etching is performed on the part of the upper side of said polycrystal silicon film having the film thickness of 2,500Angstrom with the resist 12 as a mask. The etching conditions are such that, e.g., high frequency output is 1kW, pressure of CF4, wherein 5% O2 is mixed, is 1ATM, and the treatment is performed for 2.5min. Then anisotropic etching is performed on the lower part having the film thickness of 2,500Angstrom in the same device. The etching conditions are such that the high frequency output is 1kW, pressure of CCl4 gas is 0.2atm, and the treatment is performed for 30sec. In this method, the side etching is performed at first on the film of the substrate, then, the vertical etched side is obtained, and the pattern having the side in the tapered shape is formed.

Inventors

• 👤 Chuichi Takada
• 👤 Ryoji Abe

Bibliographic Details