シリコンのDRIEにおける大小開口混在パターン一括加工技術の開発

概要

論文の詳細を見る
We have developed a new Si DRIE process, which allows simultaneous etching of both narrow and wide mask opening patterns. MEMS devices often contains a wide range of mask opening sizes from μm to mm on a same chip. Conventional DRIE process suffered from a trade off between minimizing mask-undercut for narrow grooves and eliminating ‘Black Si’ on an etched bottom surface for large mask apertures. This was caused by non-uniformity in deposition of protective polymeric layer during etching among mask aperture areas having different sizes. Our new DRIE process technique alternating the conventional DRIE and O2 plasma irradiation, adds SiO2 layer onto polymeric layer. We have clarified that the new DRIE process can form SiO2 protective layer having uniform thickness regardless of the mask aperture size. This uniformity is considered as a result of equilibrium between surface oxidation and sputtering of oxygen by plasma irradiation. We proved that our developed process allows a simultaneous etching of narrow deep grooves of 1μm width, 73μm deep, and wide aperture area of 500μm square without Black Si on a same chip.
社団法人電気学会の論文
2008-11-01