Electronic transport in heavily Si doped cubic boron nitride films epitaxially grown on diamond(001)

Structural phase analysis and measurements of electronic transport properties were carried out on heavily Si-implanted cubic ( c - ) BN films heteroepitaxially grown on diamond(001). Pure cubic phase can be conserved after Si implantation up to a concentration of 2 × 10 20 cm − 3 and a related implantation damage of 0.9 displacements per atom. As a result, the temperature dependent sheet resistance is lowered by seven orders of magnitude as compared to undoped films. By temperature dependent Hall effect measurements, n -type conduction is confirmed for these heavily Si-implanted c - B N films. Due to the high Si doping levels a semiconductor-to-metal transition is approached as signaled by the extremely small activation energies of typically 0.05 eV as well as by an almost temperature independent negative carrier concentration up to 470 K . At higher temperatures an additional activated process sets in resulting in a further increase in carrier concentration with an activation energy of 0.4 eV .