Influence of palladium doping and proton irradiation on oxygen stability and optical properties of n-type silicon
Abstract
This study investigates the combined effects of palladium diffusion doping and proton irradiation on oxygen-related defects and optical properties of n-type silicon. Pure and Pd-doped silicon samples were irradiated with 2 MeV protons at fluences of 5 × 10 14 and 1 × 10 15 cm −2 . Infrared spectroscopy identified the formation of Si–O–Si, Si–O, Si–OH, SiO 2 , and SiO 3 bonds. Palladium doping enhanced the 1106 cm −1 absorption band, indicating stabilization of interstitial oxygen in a neutral state. Proton irradiation reduced this band intensity due to the generation of radiation-induced defects, including VO and V 2 O complexes. Ellipsometric measurements revealed increases in optical parameters and effective medium approximation (EMA) layer thickness, especially in Pd-doped samples, suggesting intensified surface oxidation after irradiation. The findings demonstrate that palladium significantly influences oxygen-defect evolution and radiation-induced oxidation processes, contributing to improved resistance of silicon to irradiation-related degradation.