SiC/SiO2 interface-state generation by electron injection

Generation of interface states caused by electron injection in n- and p-typ e (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 t o the charging of thermal oxides on Si. However, the generation of interfac e states in SiC/SiO2 was larger than in Si/SiO2. The interface-state produc tion was found to be enhanced on the C face of SiC as compared to the Si fa ce, and was also found to be enhanced after carbonization of the SiC surfac e prior to oxidation, which refers to carbon involvement in the SiC/SiO2 in terface-state creation. The observed significant influence of the particula r SiC polytype on the interface degradation also suggests an involvement of SiC crystal surface imperfections in the interface-state generation. (C) 1 999 American Institute of Physics. [S0021-8979(99)07611-2].