Low-damage etching of silicon carbide in Cl2-based plasmas

Fluorine-based plasmas have been extensively reported for etching SiC in inductively coupled plasma reactive ion etching (ICP-RIE) systems for device fabrication and via-hole formation. The primary advantage of fluorine-based plasmas for etching SiC is that they yield very high etch rates. However, while high etch rates are very suitable for via-hole formation into SiC, lower etch rates are desirable for SiC device fabrication. The etching of SiC using ICP-RIE in various Cl-2-based mixtures is reported. It was found that in comparison with F-2-based gas mixtures, Cl-2-based gas mixtures induced less damage on etched SiC surfaces. Optimized etching conditions using BCl3/SF6 gas mixtures that induce minimal surface damage on SiC are reported. Results of Auger electron spectroscopy showed that etching conditions produced negligible change in surface stoichiometry. (C) 2002 The Electrochemical Society.