Semiconductor laser device
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorsTomoko Kadowaki, Takashi Murakami
Life of this patent
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Abstract
A semiconductor laser device producing visible light includes a double heterojunction structure having a first conductivity type lower cladding layer, an active layer and a second conductivity type upper cladding layer, formed in a first epitaxial growth process of AlGaInP series materials and a contact layer formed in a second or later epitaxial growth process. The contact layer is In.sub.x GA.sub.1-x As.sub.y P.sub.1-y which can be grown at a lower temperature than used in the first process. Therefore, deterioration in laser characteristics due to the diffusion of dopant impurities during the growth of contact layer can be prevented, resulting in a semiconductor laser device having high performance and long lifetime.
Claims14
A semiconductor laser device producing visible light comprising:
- a semiconductor substrate;
- a double heterojunction structure disposed on said semiconductor substrate and comprising a first conductivity type lower cladding layer, an active layer, and a second conductivity type upper cladding layer, said second cladding layer including a ridge having an upper surface and side walls;
- a first conductivity type semiconductor current blocking layer disposed on said upper cladding layer adjacent and contacting said side walls of said ridge for confining current flow to a portion of said active layer;
- a second conductivity type contact layer in electrical contact with said upper surface of said ridge of said second cladding layer comprising In.sub.x Gas.sub.1-x P;
- and
- first and second electrodes contacting said semiconductor substrate and said contact layer, respectively.
A semiconductor laser producing visible light comprising:
- a first conductivity type GaAs substrate;
- a double heterojunction structure including a first conductivity type (Al.sub.w Ga.sub.1-w).sub.0.5 In.sub.0.5 P first cladding layer disposed on the substrate, an (Al.sub.z Ga.sub.1-z).sub.0.5 In.sub.0.5 P active layer disposed on the first cladding layer, a second conductivity type (Al.sub.w Ga.sub.1-w).sub.0.5 In.sub.0.5 P second cladding layer disposed on the active layer, where z.gtoreq.0,2>z;
- a second conductivity type In.sub.x Ga.sub.1-x P contact layer in electrical contact with the second cladding layer;
- and
- first and second electrodes respectively contacting the substrate and contact layer.
Dependencies are inferred from the claim text.