| 摘要 |
PROBLEM TO BE SOLVED: To prevent the diffusion of the impurity intrinsic to a substrate into a III nitride compound semiconductor layer by forming the III nitride compound semiconductor layer on an upper face of the silicon substrate, with a side wall of the silicon substrate covered with a diffusion preventive film. SOLUTION: On a Si substrate 11 (a (111) face), a TiN layer 13 (a TiN single crystal, 3000 Å) is formed. Then, a buffer layer 14 (Al0.9Ga0.1N, 150 Å) is grown on the layer 13. Then, this buffer layer/TiN/Si sample is taken out of a chamber of a MOCVD equipment and is transferred to an oxide film formation equipment to be left as it is for 15 min, at 900 deg.C. By this process, a side face 11s and a bottom face 11b of the substrate 11 are oxidized and a silicon oxide diffusion preventive layer 18 is formed. Thereafter, the sample is moved back to the chamber of the MOCVD equipment and an n-clad layer 15 (n-GaN: Si, 4 μm), a light emitting layer 16 (a superlattice structure), and a p-clad layer 17 (p-GaN: Mg, 0.3 μm) are deposited in order. Then, the diffusion preventive layer 18 is removed by etching. |
