Characterization of crystalline SiC films grown by pulsed laser deposition

Abstract

Pulsed laser deposition (PLD) is well known as a reliable, economical technique for the growth of high-temperature superconducting oxide thin films. There are a number of interesting characteristics, however, that distinguish this method from other thin film techniques. In particular, the vapor species are typically characterized by average energies far above those encountered in thermal evaporation and chemical vapor based approaches. As a result, PLD may have the potential to realize films with a smoother morphology at low substrate temperatures if the surface species can retain some portion of the initial kinetic energy after adsorption. In this paper, we examine the PLD growth of SiC thin films on (100) silicon and (0001) sapphire substrates over a substrate temperature range of 250–900°C. In-situ characterization using reflection high-energy electron diffraction indicates that films deposited on sapphire above 700°C, using low laser fluence, initially grow as single crystal material. X-Ray diffraction shows either 3C–SiC features or no features at all, independent of the type of substrate. Atomic force microscopy shows very smooth films, with an average surface roughness of 3 Å at a substrate temperature of 250°C and 0.7 Å at 900°C.