Plasma etch models based on different plasma chemistry for micro-electro-mechanical-systems application

摘要

The suitability of different plasma etch models based on various plasma chemistry has been evaluated for the fabrication of micro-mechanical structures and micro-electro-mechanical systems. Different etch models have been described for silicon etching based on fluorine and chlorine chemistry and the mechanisms involved in SiO2 etching. Conventional planar reactive ion etching systems have been utilized for the etching Of SiO2 and silicon based on fluorine and chlorine etch models. Fluorine containing gases such as CHF3 in combination with AT have been used for SiO2 etching and achieved nearly vertical sidewalls with smooth bottom surface. Gas mixtures such as SF6/O-2 at low substrate temperatures and Cl-2/BCl3 have been used for silicon etching and sidewall passivation techniques have been employed to achieve vertical sidewalls. The usefulness of chlorine chemistry using BCl3 gas chopping technique for the fabrication of high aspect ratio structures has been demonstrated. (C) 2002 Elsevier Science Ltd. All rights reserved. [References: 22]