Vapor Phase Anisotropic Silicon Etch
Original Publication Date: 1986-Nov-01
Included in the Prior Art Database: 2005-Mar-09
This article describes a method for etching predictable geometric shapes in single crystal silicon (Si) by a gaseous etchant, producing volatile silicon reaction products. Etch rate anisotropy is defined by widely varying reaction rates among the silicon crystal planes. The method has particular application in production of micromechanical devices, e.g., some of those described by Kurt E. Petersen, in "Silicon As A Mechanical Material," Proceedings of the IEEE 70, 420-457 (May 1982). Referring to Fig. 1, a single crystal silicon wafer 2, having a <100> surface orientation and covered by either a native or grown oxide (SiO2) surface layer 4, has a photoresist pattern 6 reproduced in the oxide 4 whivh is removed from unprotected regions by a standard etching method.