• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.8
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• pp.620-627
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• 1998

For chemical microsensors such as humidity and gas sensors, it is essential to obtain a single pore with a large inner surface and straight structure. In this paper, cylindrical macroporous silicon layers have been formed of p-silicon substrate by anodization in HF-ethanol-water solution with an applied current. The pores grew normal to the (100) surface and were uniformly distributed. The pore diameter was approximately $1.5~2{\mu}m$ with a depth of $20~30{\mu}m$ and the pores were not interconnected, which are in sharp contrast to the porous silicon reported previouly for similarly doped p-Si. Porous silicon diaphragms 18 to $200{\mu}m$ thick were formed by anistropic etching in TMAH solution and then anodization. The fabrication of macroporous silicon and free-standing diaphragms is expected to offer applications for microsensors, micromachining, and separators.

• Proceedings of the KIEE Conference
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• 1998.07d
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• pp.1558-1560
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• 1998

Macroporous silicon diaphragms 20 to $200{\mu}m$ thick have been formed on p-type silicon by anistropic etching in TMAH solution and then by electrochemical etching in HF-ethanol-water solution with an applied current. The pores have a pore diameter of $1.5{\sim}2{\mu}m$, with a depth of $20{\sim}30{\mu}m$ and are not interconnected, which are in sharp contrast to the porous silicon reported previouly for similarly doped p-Si. The fabrication of macroporous silicon and free-standing diaphragms is expected to offer new applications for microsensors, micro-machining, and separators.