Large-area pulsed laser deposition of silicon carbide films

Silicon carbide (SiC) thin films are attractive for a wide range of applications ranging from microelectronic and opto-electronic devices to protective and tribological coatings. In this paper, we will demonstrate that silicon carbide films can be successfully deposited by pulsed laser deposition (PLD) technique over large areas, with good uniformity in thickness, composition, and film-specific properties. Amorphous SiC films were grown on silicon wafers of 75-mm diameter over a temperature range of 25 - 650 degreesC using a KrF excimer laser at a wavelength 248 rim and a repetition rate of 100 Hz. The large-area uniform coverage was obtained by rastering the laser beam over the radius of a rotating SiC target of 90-mm diameter, while the substrate was rotated simultaneously. The uniformity of film composition over the 75-mm wafers was characterized by Auger electron spectroscopy (AES), while the crystallinity of films was investigated by X-ray diffraction (XRD). The morphology of the films was evaluated using scanning electron microscopy (SEM) and atomic force microscopy (AFM). The thickness of the coatings, and the index of refraction, n, along the wafer radii were measured optically using a spectrophotometer.