Electrical Characteristics of Metal–Insulator Diamond Semiconductor Schottky Barrier Diode Grown on Heteroepitaxial Diamond Substrate

Abstract

Herein, the growth of lateral-structure p-type diamond Schottky barrier diodes (SBDs) on a heteroepitaxial diamond substrate using a thin atomic-layer-deposited hafnium oxide ((Formula presented.)) interfacial layer is demonstrated. The diamond SBD is grown using the microwave plasma chemical vapor deposition (MPCVD) with 1 kW microwave power at 2.45 GHz. Two kinds of samples are grown on heteroepitaxial diamond substrates under the same growth conditions for identical epi structures. And the 10 nm thickness of (Formula presented.) is used as an insulator for MIS SBD. The effects of the (Formula presented.) interlayer on the electrical properties of the SBDs are investigated using current–voltage (I–V curve) and capacitance–voltage (C–V curve) characteristics at room temperature. Compared with the metal–semiconductor (MS) SBD, the metal–insulator–semiconductor (MIS) SBD exhibited a (Formula presented.) lower reverse leakage current. The Schottky barrier height in the MIS SBD is almost 0.2 eV higher than in the MS SBD. The insertion of the (Formula presented.) interlayer reduces the inhomogeneous Schottky barrier height and enhances the barrier height because of the reduction in the interface state density.