High Aspect Ratio Si Prismatic Shape Forming Technology Using Crystallographic Orientation-Dependent Etching

Abstract

Recently, a high aspect ratio Si prismatic shape forming is an important technology to apply for the sensing device and micro pillar array structures. In a general way, a dry etching process using inductively-coupled plasma reactive ion etching (ICP-RIE) is well known to fabricate the high aspect ratio microstructure. However, the Deep RIE process generates the scalloping on the sidewall. This paper proposes the high aspect ratio shape and smooth surface prismatic shape forming technology using a Si crystal anisotropic wet etching. In this method, we can fabricate the high aspect ratio micro prismatic shape array using (110) Si crystal by Tetramethylammonium hydroxide (TMAH) wet etching. As the result, we confirmed the principle for the high aspect ratio and very smooth surface prismatic shape formation by the Si (110) anisotropic etching.