Influence of the deposition parameters on the properties of silicon carbide thin films grown by PLD

Abstract

Silicon carbide (SiC) has attracted much attention in the last years due to its excellent physical and electrical properties, such as wide bandgap, high thermal conductivity, high breakdown electric field, high saturated electron drift velocity and resistance to chemical attack. These properties make SiC a promising material for high-temperature, high-power and high-frequency electronic devices as well as for optoelectronic such as solar cells, image sensors, gas sensors and photodiodes, just to cite a few. Thin films of SiC on Si (100) and SrTiO3 (100) substrates were grown by nanosecond pulsed laser deposition (PLD) at the wavelengths of 1064, 532 and 266 nm using a Q-switched Nd:YAG laser. Upon irradiation for two hours at a repetition rate of 10 Hz and a distance target-substrate of 4 cm, deposits consisted of smooth and uniform layers, holes and cracks free, with average roughness ¿ 1 nm and with 20 to 100 nm thicknesses as determined by atomic force microscopy in tapping mode. The effect of laser irradiation wavelength, laser fluence and the temperature of the substrate (300 K vs. 1025 K) on the morphology, composition and crystallinity of the deposits was determined. Deposits were analyzed by X-ray diffraction, micro-Raman spectroscopy and X-ray photoelectron spectroscopy to characterize their crystallinity and composition. Additionally, the nanomechanical properties of the deposited films and the photoluminescence were evaluated.