Depth Profile Analysis of Deep Level Defects in 4H-SiC Introduced by Radiation

Tomislav Brodar,Željko Pastuović,Luka Snoj,Ivana Capan,Takeshi Ohshima,Vladimir Radulović,Luka Bakrač

doi:10.3390/cryst10090845

Abstract

Deep level defects created by implantation of light-helium and medium heavy carbon ions in the single ion regime and neutron irradiation in n-type 4H-SiC are characterized by the DLTS technique. Two deep levels with energies 0.4 eV (EH1) and 0.7 eV (EH3) below the conduction band minimum are created in either ion implanted and neutron irradiated material beside carbon vacancies (Z1/2). In our study, we analyze components of EH1 and EH3 deep levels based on their concentration depth profiles, in addition to (−3/=) and (=/−) transition levels of silicon vacancy. A higher EH3 deep level concentration compared to the EH1 deep level concentration and a slight shift of the EH3 concentration depth profile to larger depths indicate that an additional deep level contributes to the DLTS signal of the EH3 deep level, most probably the defect complex involving interstitials. We report on the introduction of metastable M-center by light/medium heavy ion implantation and neutron irradiation, previously reported in cases of proton and electron irradiation. Contribution of M-center to the EH1 concentration profile is presented.

Highlights

Silicon carbide (SiC) is a wide band gap semiconductor suitable for high temperature, high-frequency and high-power applications [1,2]
We investigate deep level defects in n-type 4H-SiC introduced by ion implantation and neutron radiation by the DLTS and Laplace DLTS techniques
K/min.2020, Concentration profiles of deep level defects were determined from their DLTS amplitude, Crystals

Summary

Introduction

Silicon carbide (SiC) is a wide band gap semiconductor suitable for high temperature, high-frequency and high-power applications [1,2]. Two deep levels with energies around EC —0.4 eV and EC —0.7 eV (usually labeled as S1 and S2 or EH1 and EH3, respectively [25,26,27,28,29,30,31]) can be observed in n-type 4H-SiC after irradiation with neutrons or electrons and ion implantation. Their simultaneous appearance and correlation of their concentrations indicate that they correspond to different charge state transitions of the same defect [27].

Neutron

Discussion

Depth Profiling of EH1 and EH3 Deep Level Defects

10. The profile

Methods