Low-resistance p+ layer formation into diamond using heavily B ion implantation

We examine the B dosage dependence of the lattice and electronic structures of a heavily B doped layer formed by multiple-energy B-implantation into diamond (up to 1.7×1017Bcm−2) at an elevated temperature. The resultant highly B doped diamond layer exhibits p-type conduction with very low sheet resistance of 90Ω∕◻ (0.25μm thickness) and low resistivity of 2.3mΩ cm and has temperature-independent transport properties. This suggests that a high-temperature ion implantation technique allows the formation of diamond as a p-type degenerate semiconductor with metallic conduction and provides a useful tool for selective doping required for practical diamond device processing.