Radiation defects induced by 20 MeV electrons in MOS structures

The influence of high-energy electron irradiation on the electron states at Si-SiO2 interface of n- and p-type MOS structures was studied by thermally stimulated current (TSC) method. All Si wafers were oxidised at 1000degreesC in dry oxygen to oxide thickness of 22 nm. Aluminum gate electrodes were then created by photolithography technique and the samples were irradiated with 20 MeV electrons at a fluence of 8 x 10(12) cm(-2) s(-1) for-60 or 120 s. The activation energy and the concentration of the traps are evaluated. It is shown that the main peaks in the irradiated n- and p-type MOS structures correspond to the vacancy-phosphorus or vacancy-boron complexes, respectively, that is the generated defects can be related to the main impurities in the Si substrate. (C) 2004 Elsevier Ltd. All rights reserved.