Control of n-type electrical conductivity for cubic boron nitride (c-BN) epitaxial layers by Si doping

Abstract

n-type Si-doped cubic boron nitride (c-BN) (001) layers were heteroepitaxially grown on insulating diamond (001) substrates by ion-beam-assisted molecular beam epitaxy (MBE). The Si donor ionization energy (ED) was estimated to be about 0.24 eV from the temperature dependence of the electron concentration, taking the screening effect into account. Thanks to the low concentration of residual impurities in the MBE-grown c-BN epitaxial layer, the resistivity can be widely varied from about 1 × 108 ω cm for an undoped c-BN layer to 260 ω cm for a Si-doped one with a dopant concentration of 1.5 × 1019 cm-3