Gallium nitride single crystal substrate and method of producing the same

摘要

A gallium nitride single crystal substrate being a freestanding substrate with a thickness more than 200µm. The n-type GaN substrate having a safe n-type dopant instead of Si which is introduced by perilous silane gas. The safe n-dopant is oxygen. The oxygen doped n-type GaN free-standing crystal is made by forming a mask on a GaAs substrate, making apertures on the mask for revealing the undercoat GaAs, growing GaN films through the apertures of the mask epitaxially on the GaAs substrate from a material gas including oxygen, further growing the GaN film also upon the mask for covering the mask, eliminating the GaAs substrate and the mask, and isolating a freestanding GaN single crystal. The GaN is an n-type crystal having carriers in proportion to the oxygen concentration.