| 摘要 |
PURPOSE:To eliminate dislocations in a P-type InGaAsP active layer, reduce the distance between the active layer and a P-N junction in an N-type InP cladding layer and improve the light emitting efficiency of a device by a method wherein the high impurity concentration N-type InP cladding layer is formed after the active layer is formed. CONSTITUTION:A P-type InP cladding layer 2 with an impurity concentration of 1X10<18>cm<-3>, a P-type InGaAsP active layer 3 with an impurity concentration of 1X10<19>cm<-3>, an N-type InP cladding layer 4 with an impurity concentration of 5X10<18>cm<-3> and an N-type InGaAsP cap layer 5 with an impurity concentration of 5X10<18>cm<-3> are successively formed on a P-type InP substrate 1. Further, an oxide film 6 is formed on the surface of the N-type InGaAsP cap layer 5 except a circular region M and then an electrode 7 is formed over the whole surface. An electrode 8 is formed on the surface of the P-type InP substrate 1 except a circular region N corresponding to the circular region M. With this constitution, as the N-type impurity concentration of the N-type InP cladding layer 4 is high, the degradation of the efficiency of confining carriers in the active layer 3 is suppressed and a light emitting efficiency can be improved. |
