Experimental and physics based study of the Schottky Barrier Height inhomogeneity and associated traps affecting 3C-SiC-on-Si Schottky Barrier Diodes

The ability of cubic phase (3C-) silicon carbide (SiC) to grow heteroepitaxially on silicon (Si) substrates (3C-SiC-on-Si) is an enabling feature for cost-effective wide bandgap devices and homogeneous integration with Si devices. In this article, the authors evaluated 3C-SiC-on-Si Schottky barrier contacts by fabricating and testing nonfreestanding lateral Schottky barrier diodes (LSBD). To gain a deep physical insight of the complex carrier transport phenomena that take place in this material, advanced technology computer aided design (TCAD) models were developed that allowed accurately matching of measurements with simulations. The models incorporate the device geometry, an accurate representation of the bulk material properties, and complex trapping/de-trapping and tunneling phenomena that appear to affect the device performance. The observed nonuniformities of the Schottky barrier height (SBH) were successfully modeled through the incorporation of interfacial traps. The combination of TCAD with fabrication and measurements enabled the identification of trap profiles and pin their influence on the electrical performance of 3C-SiC-on-Si LSBD. The effect of temperature was studied by engaging the identified trap profiles and calculating the occupation distribution of electrons in 3C-SiC at elevated temperature. The investigation constitutes an imperative knowledge step towards the development of devices that take advantage of 3C-SiC material properties.