Title :
Anisotropy and selectivity control of TMAH
Author_Institution :
Dept. of Mech. Eng., Ritsumeikan Univ., Kyoto, Japan
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;
Conference_Titel :
Micro Electro Mechanical Systems, 1998. MEMS 98. Proceedings., The Eleventh Annual International Workshop on
Conference_Location :
Heidelberg
Print_ISBN :
0-7803-4412-X
DOI :
10.1109/MEMSYS.1998.659759
