Radiation defects in n- and p-Si MOS structures caused by consecutive ion implantation and gamma irradiation

摘要

The influence of gamma-irradiation on the interface states in ion-implanted MOS samples was studied by the thermally stimulated current (TSC) method. Two groups of MOS based on n- and p-type Si-wafers and oxide thickness of 110 nm were implanted with 65 keV silicon ions at dose of 1.2 x 10(12) cm(-2). After implantation the samples were exposed to gamma-radiation at doses varying from 10(4) to 10(6) rad. The energy position and the concentration of interface traps before and after the gamma irradiation were determined. The electron levels at the Si-SiO2 interface created by the irradiation were found to depend on the type of silicon wafers used. The TSC of p-type MOS samples was extended to higher temperatures then for n-type, and their increment with gamma-dose was larger. (C) 2004 Elsevier Ltd. All rights reserved.