Silicon surface micromachining by anhydrous HF gas-phase etching with methanol

作者：Won Ick Jang, Chang Auck Choi, Chang S. Lee, Yoonshik Hong, Jong‐Hyun Lee, Jong Tae Baek, Bo Woo Kim · 发表于：Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 年份：1998 · DOI：10.1117/12.324292 · 被引用次数：1 · 研究领域：Nanowire Synthesis and Applications、Advanced MEMS and NEMS Technologies、Silicon Nanostructures and Photoluminescence

In silicon surface micromachining, the newly developed GPE (gas-phase etching) process was verified as a very effective method for the release of highly compliant microstructure. The developed GPE system with anhydrous HF (hydrogen fluoride) gas and CH3OH (methanol) vapor was characterized and its selective etching properties were discussed. P-doped polysilicon and SOI (silicon on insulator) substrate were used as a structural layer and TEOS (tetraethylorthosilicate) oxide and thermal oxide as a sacrificial layer. The etch rates of HF GPE were 400 angstrom/min for sacrificial TEOS oxide and 1000 angstrom/min for bulk TEOS oxide. For SOI structures, we adopted two step process of wet etch and HF GPE process to reduce the process time and confirmed relatively low etch rate of 55 angstrom/min for 1.8 micrometer-thick thermal oxide after 6:1 BHF etching for 15 minutes.