EFFECTS OF C OR SI COIMPLANTATION ON THE ELECTRICAL ACTIVATION OF B-ATOMS IMPLANTED IN 4H-SIC

The influence of co-implantation of C or Si ions on the electrical act ivation of B accepters in 4H-SiC was studied by using Hall effect and photoluminescence (PL) investigations. The free hole concentration in B-implanted layers is found to increase due to co-implantation of C an d to decrease owing to Si co-implantation, Hot co-implantation of C at 800 degrees C gives rise to a further increase of the free hole conce ntration. It is found that the intensity of the PL peak at a wavelengt h 383.9 nm, which arises from shallow B accepters [Sridhara et al., Ma ter. Sci. Forum 264-268, 461 (1998)], is enhanced by the coimplantatio n of C. These results demonstrate that the electrical properties of B- implanted p-type layers are improved by C co-implantation. The mechani sms, which alter the electrical activation of implanted B atoms due to co-implantation of C or Si, are discussed. (C) 1998 American Institut e of Physics. [S0003-6951(98)02036-1].