Patent ID: 7899104

Claim:
An EL semiconductor device comprising: an InP substrate having at least n-type cladding layer, active layer, and p-type cladding layer formed thereon, wherein (i) the n-type cladding layer is a single layer film of which a composition ratio of Mg x ZN 1-x Se y Te 1-y in the n-type cladding layer is above 80% and below 100%, and a composition ratio of Se in the Mg x Zn 1-x Se y Te 1-y , y, is above 0.5; or (ii) the n-type cladding layer is formed of a laminate film containing Mg x Zn 1-x Se y Te 1-y , in which the laminate film has at least a pair of two layers composed of a first layer with a composition ratio of Mg x Zn 1-x Se y Te 1-y being above 80% and below 100% and a composition ratio of Se in Mg x Zn 1-x Se y Te 1-y , y, being above 0.5 and of a second layer with a composition ratio of MgSe being above 80% and below 100%, and the pair of the laminate film is superposed and piled up repeatedly a plural number of times, and wherein (iii) the active layer is a single layer film of which a composition ratio of BeZnSeTe in the active layer is above 80% and below 100%, and a lattice parameter (a a ) of the BeZnSeTe and a lattice parameter (a InP ) of the InP substrate satisfy a condition of −0.01<(a a −a InP )/a InP <0.01; or (iv) the active layer includes at least a first layer and a second layer, in which a composition ratio of BeZnSeTe in the first layer is above 80% and below 100%, a lattice parameter (a a ) of the BeZnSeTe and a lattice parameter (aInP) of the InP substrate satisfy a condition of −0.01<(a a −a InP )/a InP <0.01, and a composition ratio of MgSe in the second layer is above 80% and below 100%, and in which a pair of a laminate film including at least two layers composed of the first layer and the second layer is superposed and piled up repeatedly a plural number of times; or (v) the active layer includes at least a first layer and a second layer, in which a composition ratio of BeZnTe in the first layer is above 80% and below 100%, a lattice parameter (a a ) of the BeZnTe, and a composition ratio of ZnSe in the second layer is above 80% and below 100%, and in which a pair of a laminate film including at least two layers composed of the first layer and the second layer is superposed and piled up repeatedly a plural number of times.