Metal-intrinsic semiconductor-semiconductor structures using polycrystalline diamond films

Abstract

The electrical characteristics of a metal-intrinsic semiconductor-semiconductor structure formed by Al-undoped polycrystalline diamond-B-doped polycrystalline diamond were investigated. Boron-doped diamond films containing B-to-C ratios of 400 and 4000 ppm in gas phase were deposited on (111)-oriented B-doped Si substrates. Subsequently, undoped diamond layers were deposited on the B-doped diamond films for 60 min. The existence of a bilayer structure in terms of the atomic B concentration was confirmed by a secondary-ion mass spectroscopy. Significant improvements in the rectifying characteristics could be obtained with the introduction of an undoped diamond layer.