Electric conductivity of boron nitride thin films enhanced by in situ doping of zinc

The authors demonstrate that the electric conductivities of cubic and hexagonal boron nitride (c-BN and h-BN) thin films increased markedly by the in situ doping of zinc. The doped films were electrically semiconducting, and conductivities at room temperature increased from 10−8to10−2Ω−1cm−1 with increasing zinc concentration from 400to20000ppm. Activation energies for electric conduction (Ec) of c-BN decreased from 0.3to0.1eV with increasing zinc concentration, suggesting feasible shallow-level doping. On the other hand, h-BN thin films showed approximately 0.1eV higher Ec than those of c-BN’s, due to the formation of defective B–B bonds.