The structure and photoluminescence properties of SiC films doped with Al

SiC films doped with Al were prepared by the RF-magnetron sputtering technique on p-Si substrates with a composite target of a single crystalline SiC containing several Al pieces on the surface. The as-deposited films were annealed in the temperature range of 400-800 °C under nitrogen ambient. The thin films have been characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The results showed that annealing temperature has an important role in the quality of the samples and leads to the increase in the size of particles. The introduction of Al into films hinders the Si particles from reacting completely with C particles to synthesize SiC and hinders the crystalline formation process. The more Al in the films, the more apparent this phenomenon. When more Al was doped in the films, the Si-C peak is shifted to the lower wave numbers (735 cm−1), and more Si particles have formed. Photoluminescence (PL) spectra of the samples were observed in the visible range at room temperature. The origin of the two PL peaks (370 and 412 nm) in sample A and sample B and the double-peak structure in sample C (416 and 440 nm) were discussed.