Growth and electrical characterisation of δ-doped boron layers on (111) diamond surfaces

Abstract

A plasma enhanced chemical vapor deposition protocol for the growth of δ-doping of boron in diamond is presented, using the (111) diamond plane as a substrate for diamond growth. AC Hall effect measurements have been performed on oxygen terminated δ-layers and desirable sheet carrier densities (∼1013 cm−2) for field-effect transistor application are reported with mobilities in excess of what would expected for equivalent but thicker heavily boron-doped diamond films. Temperature-dependent impedance spectroscopy and secondary ion mass spectroscopy measurements show that the grown layers have metallic-like electrical properties with high cut-off frequencies and low thermal impedance activation energies with estimated boron concentrations of approximately 1020 cm−3.