SiC/SiO2 interface-state generation by electron injection

Generation of interface states caused by electron injection in n- and p-type (3C, 4H, 6H)-SiC/ SiO2/metal structures was studied using photoinjection methods. The charge trapping in the oxides on SiC was found to be similar to the charging of thermal oxides on Si. However, the generation of interface states in SiC/SiO2 was larger than in Si/SiO2. The interface-state production was found to be enhanced on the C face of SiC as compared to the Si face, and was also found to be enhanced after carbonization of the SiC surface prior to oxidation, which refers to carbon involvement in the SiC/SiO2 interface-state creation. The observed significant influence of the particular SiC polytype on the interface degradation also suggests an involvement of SiC crystal surface imperfections in the interface-state generation. (C) 1999 American Institute of Physics. [S0021-8979(99)07611-2].