HIGHLY ANISOTROPIC SILICON AND POLYSILICON ROOM-TEMPERATURE ETCHING USING FLUORINE-BASED HIGH-DENSITY PLASMAS

A highly anisotropic Si and Polysilicon plasma etching process at room temperature has been developed in an inductively coupled plasma (ICP) reactor using SF6/CHF3 gas mixtures. The etching rates achieved are m uch higher than those obtained in a reactive ion etching reactor (RIE) , using a similar F-based room temperature process. Etched structures are analysed by SEM and surface chemical analysis (ESCA), while the pl asma gas phase is analysed by Optical Emission Spectroscopy (OES).