WAFER MARKING METHOD, METHOD OF PRODUCING NITRIDE SEMICONDUCTOR DEVICE AND NITRIDE SEMICONDUCTOR SUBSTRATE

A wafer marking method uses a laser for performing a laser marking on a defect region of a nitride semiconductor substrate in which a nitride semiconductor layer contains at least a GaN layer formed by epitaxial growth on a single-crystal silicon substrate. The method includes that a surface of the GaN layer and a surface of the single-crystal silicon substrate are performed laser marking simultaneously by irradiating the defect region with a laser of a wavelength within ±10% of 365 nm, having a wavelength corresponding to a band gap energy of GaN.