Anisotropy and selectivity control of TMAH

Author

Tabata, O.

Author_Institution

Dept. of Mech. Eng., Ritsumeikan Univ., Kyoto, Japan

fYear

1998

fDate

25-29 Jan 1998

Firstpage

229

Lastpage

233

Abstract

A new approach to control the characteristics of TMAH silicon anisotropic etchant is proposed. The effects of potassium ions on TMAH etching characteristics at a concentration of 20 wt.% and temperature of 80°C were investigated. A K₂CO₃ additive to the TMAH was used as a potassium ion source. The SiO₂ etching rate increased with increasing the amount of added K₂CO₃. Anisotropic etching characteristics were measured using a wagon wheel pattern. It was observed that the etched wagon wheel pattern changed with increasing the amount of added K₂CO₃. This change was caused by a decrease in the etching rate in the silicon ⟨014⟩ direction. From these results, it is concluded that important characteristics of silicon anisotropic etching, such as selectivity to silicon dioxide and anisotropy, can be controlled by adding potassium ions to TMAH solution

Keywords

elemental semiconductors; etching; micromechanical devices; potassium compounds; silicon; silicon compounds; 80 C; K ions; K₂CO₃; K₂CO₃ additive; MEMS; Si; Si anisotropic etching; Si-SiO₂; SiO₂ etching rate; Sin ⟨014⟩ direction; TMAH solution; anisotropic etching characteristics; potassium ion source; selectivity; wagon wheel pattern; Anisotropic magnetoresistance; Etching; Fabrication; Ion sources; Mechanical engineering; Micromechanical devices; Silicon compounds; Temperature; Thickness measurement; Wheels;

fLanguage

English

Publisher

ieee

Conference_Titel

Micro Electro Mechanical Systems, 1998. MEMS 98. Proceedings., The Eleventh Annual International Workshop on

Conference_Location

Heidelberg

ISSN

1084-6999

Print_ISBN

0-7803-4412-X

Type

conf

DOI

10.1109/MEMSYS.1998.659759

Filename

659759