SEMICONDUCTOR DEVICE
 Inventors: John Rennie, Tokyo; Genichi
Hatakoshi, Yokohama, both of Japan
 Assignee: Kabushiki Kaisha Toshiba, Kawasaki, Japan
 Appl. No.: 806,638
 Filed: Feb. 26, 1997
 Foreign Application Priority Data
Feb. 26, 1996 [JP] Japan 8-038260
 Int. CI.6 H01L 33/00
 U.S. CI 257/96; 257/99; 257/102;
257/103; 257/15; 257/22
 Field of Search 257/15, 22, 96,
257/99, 102, 103; 372/45, 46
 References Cited
U.S. PATENT DOCUMENTS
5,617,446 4/1997 Ishibashi et al 257/99
5,670,798 9/1997 Schetzina 257/101
FOREIGN PATENT DOCUMENTS
57-10280 1/1982 Japan .
4-213878 8/1992 Japan .
7-202265 8/1995 Japan .
Disclosed is a long-life GaN-based semiconductor device which is achieved by reducing the operating voltage of the semiconductor device comprising a GaN-based or a ZnSebased compound semiconductor formed on a sapphire substrate and by preventing the electromigration of metal atoms from an electrode into compound semiconductor layers. The operating voltage of the GaN-based or ZnSe-based semiconductor device formed on a sapphire substrate or a SiC substrate can be greatly reduced by employing a ZnO layer doped with a significant amount of Al as a material for forming ohmic contact to p- or n- compound semiconductor layers. The long-life GaN-based semiconductor device can be attained by preventing electromigration of atoms from a metallic electrode by use of ZnO layer. If a superlattice including the ZnO layer is employed as an optical guide layer or if the superlattice including the ZnO layer as an active layer, a long-life laser diode with a low operating voltage and a wide wavelength range can be obtained.
21 Claims, 13 Drawing Sheets