Study on SOI structure irradiated by electron and annealled treatment using C–V, FTIR and PL

Abstract

Abstract In this work, the commercial silicon on insulator (SOI) wafers irradiated by 0.5 MeV electrons with a fluence of 1.5⨯1014 ~ 2.3⨯1015 cm−2 and annealed among 150 °C and 300 °C have been studied in detail. The performances of SOI samples are investigated by Geant4, Capacitance - Voltage (C–V), Fourier Transform Infrared Spectroscopy (FTIR) and Photoluminescence (PL). The C–V measurements indicate that capacitance decrease under positive voltage bias with increasing fluence. The free carrier concentration decreases with increasing fluence and increases with rising annealing temperature, which can be attributed to the traps induced by electron irradiation on Si/SiO2 interface. There is only the presence of Si–O bonding from the FTIR absorption peaks exhibiting at ~940, ~960, and ~1170 cm−1. The relative intensity of three peaks become weaker with higher irradiation fluence and annealing under 150 °C, which is in good agreement with the Monte Carlo numerical simulation (Geant4). The PL spectra reveals that there is a strong photoluminescence emission at about 420 nm (2.95 eV), which is ascribed to the radiative recombination centers in SiO2 layer. In addition, weaker peaks of PL emission at 720 nm (1.72 eV) and 835 nm (1.49 eV) are also discussed in this paper.