| 摘要 |
PROBLEM TO BE SOLVED: To lower the operating voltage by increasing the carrier concentration of a II-VI semiconductor layer between a p-side electrode and a p-type clad layer. SOLUTION: An n-type clad layer 3, a first guide layer 4, an active layer 5, a second guide layer 6, a p-type clad layer 7, an underlying layer 8, a contact layer 9, a super lattice layer 10 and a cap layer 11 are laminated sequentially on an n-type substrate 1. The cap layer 11 is constituted of p-type ZnTe with a thickness of less than 10 nm. The contact layer 9 is composed of p-type ZnSe and the concentration of nitrogen being added to the contact layer 9 is set at 1-2×10<18> cm<-3> . The underlying layer 8 is composed of mixed crystal of p-type ZnSSe and the concentration of nitrogen being added to the underlying layer 8 is set at 1-3×10<18> cm<-3> , which is higher than that for the contact layer 9. When each II-VI compound semiconductor layer is formed by MBE, the cell temperature is precedingly raised temporarily. The growth temperature is lowered before the underlying layer 8 and the like is grown. |
