Silicon carbide (hereinafter also referred to as SiC) is characterized by a low lattice constant difference with gallium nitride (hereinafter also referred to as GaN) based semiconductors, high heat resistance, high hardness, and being a wide bandgap semiconductor, or the like. Thus, thin film of silicon carbide has high industrial utility value. For example, there has been an increased interest in utilizing the silicon carbide as a high-strength protective film capable of withstanding high temperatures, a buffer layer for a substrate at the time of growth of a GaN-based semiconductor, and a window material for optical equipment utilizing high light transmittance.
In industrial application of the silicon carbide film, it is desired to form a thin film having a large area having few defects and high film thickness uniformity. JP 2004-103671 describes a method for forming a high quality silicon carbide film on a silicon substrate.