Sumitomo Precision Products Co., Ltd.

Kazuo Kasai

Masuhiro Kogoma

Yoshiyuki Nozawa

Sachiko Okazaki

Hiroaki Kouno

Masahiro Hirakawa

A method for etching a silicon substrate is presented in which fast etching speed and etching structures with smooth and perpendicular wall surfaces are achieved. In the etching step, a constant electric power is applied to the silicon substrate to provide a bias potential. Using a mixture of SFgas and fluorocarbon gas, there is a step mainly for the progression of dry etching of the etching ground surface. Similarly, using a mixture gas, there is a step mainly for forming a protective layer on the structure surfaces which are perpendicular with respect to the etching ground surface. These two steps are repeated one after the other. In the step for dry etching, the mixture gas is 5&#x2013;12 volume of fluorocarbon gas with respect to 100 volume SFgas. The mixture gas in the protective film formation step is a mixture of 2&#x2013;5 volume of SFgas with respect to 100 volume fluorocarbon gas.

Growing community of inventors

Amagasaki, Japan

Kazuo Kasai