Introduction of phosphorus atoms in silicon carbide using nuclear transmutation doping at elevated temperatures
Oshima, Takeshi; Morishita, Norio; Kamiya, Tomihiro; Isoya, Junichi*; Baba, Shinichi; Aihara, Jun ; Yamaji, Masatoshi*; Ishihara, Masahiro
For the application of SiC to electronic devices, it is necessary to develop the fabrication technique of high quality SiC substrates with uniform carrier concentration. Since phosphorus (P) atoms become shallow donors in SiC, nuclear transmutation doping (NTD) is thought to be a good method for the fabrication of n-type SiC substrates with uniform electron concentration. However, defects are also introduced in SiC by neutron irradiation. Although thermal annealing at high temperatures above 1500C is carried out to remove defects after irradiation, heavy damage in SiC is hard to recover. Therefore, the process for the reduction of defects in SiC irradiated with neutrons is necessary to develop. In this study, neutron irradiation into SiC at elevated temperature was carried out to decrease radiation damage. The electrical properties of the samples are studied using Hall effect measurement. Furthermore, to establish the measurement technique for the estimation of P atoms created in SiC by NTD, P atoms in SiC were investigated using Electron Spin Resonance (ESR).