EPR and ODEPR investigations on the microscopic structure of the boron acceptor in 6H-SiC

摘要

The boron acceptor in 6H-SiC was investigated with electron paramagnetic resonance (EPR) and optically detected EPR (ODEPR). New results on the temperature dependence of the EPR were obtained at 142 GHz. With ODEPR the level Bo/- was confirmed to be at E_V+300 mV. When the B acceptor captures a hole at 1.5K, the B hf interaction is reduced to about one half of the value observed with conventional EPR previously. A detailed microscopic model of the Bsi defects will be proposed according to which B occupies a Si site as B_(Si), the hole being at an adjacent C relaxed towards Si by 15%. The relaxation has a thermal barrier Therefore C is not relaxed when B_(si)~-C~+ is formed at low temperature