In situ Si doping of heteroepitaxially grown c-BN thin films at different temperatures

Abstract

Phase pure cubic boron nitride (c-BN) films have been epitaxially grown on (001) diamond substrates at 420 C, 600 C and 900 C. Si was added during film growth at these different deposition temperatures in order to achieve in situ n-type doping. The Si concentration increases as the growth temperature decreases. The effects of the different deposition temperatures and the silicon concentration on the transport properties of the c-BN epitaxial films have been systematically investigated. The results demonstrate that the film doped at 420 C has lower resistivity than the ones doped at elevated temperatures. The temperature dependence of the electron transport properties and their corresponding theoretical fittings reveal that the activation energy of Si doped films is about 0.3 eV and the increased Si concentration could improve the compensation from the deep-level acceptors.

Tunable n-Type Conductivity and Transport Properties of Cubic Boron Nitride via Carbon Doping

“…Figure 6a shows a consistent drop in charge carrier mobility with the increasing doping concentration of C. The Hall measurement shows that C-doped c-BN samples exhibit n-type semiconductor behavior, whereas undoped c-BN usually displays p-type behavior due to the presence of nitrogen vacancies. 10 Under typical ambient conditions, the undoped c-BN shows higher resistivity which implies the presence of lower sheet hole density but greater Hall mobility, experimentally determined by Yin et al 36 Therefore, the introduction of C dopants in c-BN films increases the strain and thus introduces scattering centers for the free charge carriers, i.e., electrons in this case. These scattering centers are mainly responsible for the drop in electron mobility.…”

“…In contrast, dopants like Be, Mg, and Zn give p-type conductivity and S, C, and Si give n-type doping in c-BN, which offers a solution to the problem . Incorporating impurities into c-BN thin films were performed by in situ doping, high-temperature thermal diffusion process, or ion implantation technique followed by rapid thermal annealing (RTA). − Incorporation of Si as a n-type dopant by the in situ doping technique was reported, but the strain may convert the cubic phase into hexagonal boron nitride (h-BN) phase at high Si concentrations . In addition to that, at high substrate temperature, the impurity atoms tend to segregate toward the film surface presumably as a result of large-size misfit strain.…”

Structural and electronic properties of c-BN (111) surface with hydrogen/fluorine functionalization and nitrogen-based small-molecule adsorption

“…with sp 3 atomic bonds [3,4], hexagonal (h-BN), rhombohedral (r-BN) [5], turbostratic (t-BN) and orthorhombic (o-BN) [6] structures are composed of sp 2 or mixed sp 2 /sp 3 bonds. Additionally, p-type and n-type c-BN semiconductors have been prepared by Be, Si or S doping under high-pressure and high-temperature conditions, ion beam assisted deposition [4,[7][8][9].…”