Deposition of diamond films on single crystalline silicon carbide substrates

Silicon carbide (SiC) is a wide band gap material that is slowly but steadily asserting itself as a reliable alternative to silicon (Si) for high temperature electronics applications, in particular for the electrical vehicles industry. The passivation of SiC devices with diamond films is expected to decrease leakage currents and avoid premature breakdown of the devices, leading to more efficient devices. However, for an efficient passivation the interface between both materials needs to be virtually void free and high quality diamond films are required from the first stages of growth. In order to evaluate the impact of the deposition and seeding parameters in the properties of the deposits, diamond films were deposited on SiC substrates by hot filament chemical vapor deposition (HFCVD). Before the seeding step the substrates were exposed to diamond growth conditions (pretreatment PT) and seeding was performed with a solution of detonation nanodiamond (DND) particles and with 6-12 and 40-60 mu m grit. Diamond films were then grown at different temperatures and with different methane concentrations and the deposits were observed in a scanning electron microscope (SEM); their quality was assessed with Raman spectroscopy.