Time Evolution of Nanoscale Surface Topography of Tungsten Carbide Coatings on “Hot” Silicon Carbide Electronics Devices

Abstract

ABSTRACTWe are reporting here on the current status of our investigations on the time evolution of nanoscale surface morphology of thermally evaporated tungsten carbide coatings on silicon carbide substrates. The purpose of the study is to develop a recipe for creating thermally and chemically stable electrical contacts on silicon carbide electronic devices able to work at elevated temperatures (up to 800 °C) in oxidizing environments. We used thermal evaporation and tungsten carbide (WC) powder as a starting material to produce the thin layer deposition on semi-insulating silicon carbide (6H). Our intended applications are for devices working at 800 °C; therefore, our investigations are carried out at 1 hr intervals of time the samples spent at this temperature, in air at atmospheric pressure. We used Rutherford Backscattering Spectrometry (RBS) for measuring the stoichiometry and depth profile, and Atomic Force Microscopy (AFM) to monitor the surface morphology change.