| 摘要 |
PURPOSE:To form a semiconductor light emitting element comprising an InGaAsP-InP based semiconductor characterized by high reliability, a high yield rate and high light emitting efficiency, by sequentially forming a clad layer, an InGaAsP layer having a energy gap larger than that of an active layer and an InGaAs layer having a energy gap smaller than that of the active layer in contact with the active layer, and forming an electrode on the InGaAs layer having the energy gap smaller than that of the active layer. CONSTITUTION:This element comprises an InGaAsP-InP based semiconductor and has a double-heterojunction structure. In contact with a P-type clad layer 4, a P-type InGaAsP layer 5 having a energy gap larger than that of an active layer is provided. In contact with said P-type InGaAsP layer 5, a P-type InGaAs layer 6 having a energy gap smaller than that of the active layer is formed, and the layer 6 is used as an ohmic contact layer. The ohmic contact layer 6 is made to be a semiconductor layer having a small energy gap, e.g., an In0.47Ga0.53As layer (Eg=0.75eV). Thus the ohmic contact resistance can be made small. The InGaAsP layer having the energy gap larger than that of the wavelength of the emitted light is provided in contact with the semiconductor layer 6 having the small energy gap on the side of the active layer. Thus the chemical reaction of alloying among an electrode on the P side, the clad layer 4 and the active layer 3 is suppressed, and reliability is improved to a large extent. |
