Photo-induced preferential anodization for fabrication of monocrystalline micromechanical structures

Author

Yoshida, Takashi ; Kudo, Takahiro ; Ikeda, Kyoichi

Author_Institution

Yokogawa Electric Corp., Tokyo, Japan

fYear

1992

fDate

4-7 Feb 1992

Firstpage

56

Lastpage

61

Abstract

Photo-induced preferential anodization (PIPA) for fabrication of monocrystalline micromechanical structures is presented. P-type silicon formed in an n-type substrate is preferentially anodized in an aqueous solution of hydrofluoric acid under illumination. This technology is based on anodization and the photovoltaic effect. In experiments, dependence on light intensity, HF concentration, and the ratio of the pn-junction area to the entrance area of the HF solution was investigated. It was found that porous silicon conditions depend on light intensity and HF concentration and that anodic current density provided by a pn-junction is the most important factor for controlling PIPA. A monocrystalline microbridge structure 1 μm thick, 20 μm wide, and 300 μm long was formed using this technology

Keywords

anodisation; electric sensing devices; micromechanical devices; photovoltaic effects; silicon; HF-H₂O solution; Si; anodic current density; fabrication; light intensity; monocrystalline microbridge structure; monocrystalline micromechanical structures; photo-induced preferential anodisation; photovoltaic effect; Contamination; Current density; Electrodes; Fabrication; Hafnium; Lighting; Micromechanical devices; Photovoltaic cells; Research and development; Silicon;

fLanguage

English

Publisher

ieee

Conference_Titel

Micro Electro Mechanical Systems, 1992, MEMS '92, Proceedings. An Investigation of Micro Structures, Sensors, Actuators, Machines and Robot. IEEE

Conference_Location

Travemunde

Print_ISBN

0-7803-0497-7

Type

conf

DOI

10.1109/MEMSYS.1992.187690

Filename

187690