Experimental analysis of I‐V and C‐V characteristics of Ni/SiO2/4H‐SiC system with varying oxide thickness

Abstract

PurposeThe purpose of this paper is to electrically examine the quality of thin thermally grown SiO2 with thickness variation, on Si‐face of 4H‐SiC <0001> (having 50 μm epitaxial layer) by current‐voltage (I‐V) and capacitance‐voltage (C‐V) methods.Design/methodology/approachMetal‐oxide‐silicon carbide (MOSiC) structures with varying oxide thickness have been fabricated on device grade 4H‐SiC substrate. Ni has been used for gate metal on thermally oxidized Si‐face and a composite layer of Ti‐Au has been used for Ohmic contact on the highly doped C‐face of the substrate. Each structure was diced and bonded on a TO‐8 header with a suitable wire bonding for further testing using in‐house developed LabVIEW‐based computer aided measurement setup.FindingsThe leakage current of fabricated structures shows an asymmetric behavior with the polarity of gate bias ( + V or −V at the anode). A strong relation of oxide thickness and temperature on effective barrier height at SiO2/4H‐SiC interface as well as on oxide charges have been established and reported in this paper.Originality/valueThe paper focuses on the development of 4H‐SiC based device technology in the fabrication of MOSiC‐based integrated structures.