Electrical characteristics of metal-oxide-semiconductor capacitors on plasma etch-damaged silicon carbide

Abstract

The characteristics of metal-oxide-semiconductor (MOS) capacitors formed on inductively coupled plasma (ICP) etch-damaged SiC have been investigated. MOS capacitors were prepared by dry-oxidation on ICP-etch-damaged n- and p-type. 6H- and 4H-SiC. The effect of a sacrificial oxidation treatment on the damaged surfaces has also been examined. Capacitance-voltage and current-voltage measurements of these capacitors were performed and referenced to those of simultaneously prepared control samples without etch damage. The effective interface densities (N-IT) and fixed oxide charges (Q(V)) of etch-damaged samples have been found to increase while the breakdown field strength (E-BD) of the oxide decreases. The barrier height (phib) at the SiC-SiO2, interface, determined from a Fowler-Nordheim analysis, decreased for MOS capacitors on etch-damaged surfaces. It has been found that a sacrificial oxidation treatment can improve the electrical characteristics of MOS capacitors on etch-damaged SiC. (C) 2002 Elsevier Science Ltd. All rights reserved.