Silicon anisotropic etching of TMAH solution

Sonphao, W.; Chaisirikul, S.

Silicon anisotropic etching of TMAH solution

Author(s)

Sonphao, W.

Chaisirikul, S.

Date Issued

January 1, 2001

Type

Conference Paper

Abstract

Detailed characteristics of tetramathyl ammonium hydroxide (TMAH, (CH3)4 NOH) as silicon anisotropic etching solution with various concentration from 5 to 40 wt% and temperature 60 to 90°C have been studied. The etching of (100) crystal decreases with increasing concentration and decreasing temperature. The etched (100) planes are covered by pyramidal hillock below 15 wt% and very smooth surfaces are obtained above 22 wt% solution. The etch rate of silicon dioxide is almost four order of magnitude lower than that for (100) planes. The etch rate of aluminium are reduced by dissolving silicon in TMAH solution. Finally this paper presents different characteristics of etching in three etchants; EPD, KOH and TMAH solution and away to control the geometrical structure of the accelerometer proof mass by method of convex corner compensation which can be categorized to square corner compensation, 45 degree rectangle corner compensation and triangle corner compensation method.

Citation

IEEE International Symposium on Industrial Electronics, 3, 2049-2052, 2001