P-BN/n-Si Heterojunction Prepared by Beryllium ion Implantation

A boron nitride (BN)/silicon p-n heterojunction is fabricated by implanting beryllium (Be) ions into the BN films deposited by rf sputtering on n-type Si (111) substrates. The FTIR observations indicate that the films deposited have a mixed phase composition of sp2- and sp3-hybridized BN. Considering the thickness of the BN layer, the ion implantation is conducted at an ionenergy of 100keV with the dose of 5×1015cm-2. After annealing at a high temperature, the surface resistance of the BN film decreases significantly by 6 orders down to 1.2×105Ω. Space-charge-limited current characteristic, which indicates the existence of shallow traps in the film, is observed. Current-voltage measurements across the BN film and the Si substrate reveal a clearrectification feature, demonstrating the achievement of p-type doping of BN films by Be ion implantation.