Raman Characterization of SiC(0001) with Hydrogen Passivated Surface

Silicon carbide (SiC) is a widely used substrate for thin film deposition and semiconductor applications. For many such uses, the SiC surface must be atomically flat and cleaned by high-temperature annealing, then passivated with hydrogen atoms. To achieve hydrogen passivation, we constructed a custom hydrogen chamber capable of ultra-high vacuum (UHV) and 1600°C heating concurrent with high-purity hydrogen flow. We used atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) to confirm the topography and chemical composition of the substrate surface. Because hydrogen is too small to be imaged by AFM, and too light to be seen by XPS, we demonstrated that Raman spectroscopy can identify the Si-H bonds of the SiC(0001) surface. We report on the optimization of hydrogen annealing conditions to achieve atomically flat SiC with hydrogen passivation.