Electrical Activation of B+-Ions Implanted into 4H-SiC

Abstract

Boron (B) ions were implanted into 4H-SiC. In order to avoid the out-diffusion of B ions during the subsequent annealing process, two processing techniques were applied. Either a box-shaped B-profile was implanted, which was followed by a two-step annealing (900°C for 120 min + annealing temperature TA for 30 min), or a box-shaped B-profile was implanted together with two carbon (C) Gaussian profiles located on both edges of the B box-profile followed by a one-step annealing (TA for 30 min). The annealing temperature TA ranged from 1500°C to 1750°C. The electrically activated B acceptor concentration was measured by temperature-dependent Hall effect and the energy for the formation of the B acceptor was determined assuming a first order process.