A method for characterizing near-interface traps in SiC metal–oxide–semiconductor capacitors from conductance–temperature spectroscopy measurements

Abstract

The state-of-the-art technology for gate oxides on SiC involves the introduction of nitrogen to reduce the density of interface defects. However, SiC metal–oxide–semiconductor (MOS) field-effect transistors still suffer from low channel mobility even after the nitridation treatment. Recent reports have indicated that this is due to near-interface traps (NITs) that communicate with electrons in the SiC conduction band via tunneling. In light of this evidence, it is clear that conventional interface trap analysis is not appropriate for these defects. To address this shortcoming, we introduce a new characterization method based on conductance–temperature spectroscopy. We present simple equations to facilitate the comparison of different fabrication methods based on the density and location of NITs and give some information about their origin. These techniques can also be applied to NITs in other MOS structures.