| 摘要 |
PROBLEM TO BE SOLVED: To provide a crystal substrate having a GaN system crystal continuous film with low defective density and high quality which is suitable for the crystal growth of a GaN system semiconductor device, and a method for manufacturing this crystal substrate. SOLUTION: In this crystal substrate, plural island-shaped GaN system crystals 11 and a GaN system crystal continuous film 12 formed on this are formed on a substrate 10 in which a GaN buffer layer 102, epitaxial growth GaN layer 103, and SiO2 film 104 are successively grown on a sapphire substrate 101 whose surface is a C face. The SiO2 film 104 having plural openings 105 is formed on the surface of the GaN layer 103 by vacuum evaporation or a CVD method, GaN powder materials are sublimated in the mixed atmosphere of NH3 and N2 , and GaN system compounds are selectively re-crystallized on the openings 105 on the substrate. This method is constituted of a first crystal growing process for obtaining the plural island-shaped GaN system crystals 11, and a second crystal growing process for obtaining the GaN system crystal continuous films 12 by forming a GaN system crystal by using the crystal 11 as a core. |
