| abstract |
A high-quality GaN-based semiconductor free-standing substrate for a substrate capable of obtaining sufficient electronic device characteristics is provided. A self-supporting substrate is made of GaN, and an RMS value at 1 × 1 μm 2 measured by an AFM (Atomic Force Microscopy) in a region excluding 1 mm around the surface is 1 nm or less, and by TOF-SIMS, The peak intensity ratio of the ion mass spectrum of SiO 2 / Ga on the surface measured at primary ion Au, primary ion acceleration voltage 25 kV, scanning region 200 μm square, and secondary ion integration time 150 seconds is 0.1 or less. The surface is a self-supporting substrate having a dislocation density of 1 × 10 7 cm −2 or less, which is polished using colloidal silica as abrasive particles. [Selection figure] None |