Triangle pore arrays fabricated on Si (111) substrate by sphere lithography combined with metal-assisted chemical etching and anisotropic chemical etching.
The morphological change of silicon macropore arrays formed by metal-assisted chemical etching using shape-controlled Au thin film arrays was investigated during anisotropic chemical etching in tetramethylammonium hydroxide (TMAH) aqueous solution. After the deposition of Au as the etching catalyst on (111) silicon through a honeycomb mask prepared by sphere lithography, the specimens were etched in a mixed solution of HF and H2O2 at room temperature, resulting in the formation of ordered macropores in silicon along the [111] direction, which is not achievable by conventional chemical etching without a catalyst. In the anisotropic etching in TMAH, the macropores changed from being circular to being hexagonal and finally to being triangular, owing to the difference in etching rate between the crystal planes.
Department of Applied Chemistry, Kogakuin University, 2665-1 Nakano, Hachioji, Tokyo, 192-0015, Japan. sachiono@cc.kogakuin.ac.jp.
Hidetaka
H
Asoh
Kosuke
K
Fujihara
Sachiko
S
Ono