Monitoring of chemical oxide removal from silicon surfaces using a surfacephotovoltage technique

The goal of this study was to develop a method for in-line real-time monito ring of chemical oxide removal in integrated processes requiring an oxide e tching step. Specifically, the surface photovoltage technique based noncont act surface charge profiling (SCP) method was investigated. The surface rec ombination lifetime measured by SCP is sensitive to the presence of chemica l oxide on the surface formed in ammonia-hydrogen peroxide-water (APM) and sulfuric acid-hydrogen peroxide-water (SPM) solutions, but not in hydrochlo ric acid-hydrogen peroxide-water (HPM) solution. It is suggested that the r ecombination centers are most likely associated with interfacial bonding de fects and iron contamination in APM chemical oxides and with oxidized sulfu r in SPM chemical oxides. (C) 1998 The Electrochemical Society. S1099-0062( 98)-04-047-4. All rights reserved.