Semiconductor laser and method of manufacturing the same
AssigneeSumitomo Electric Industries, Ltd.
InventorsIchiro Yoshida, Tsukuru Katsuyama, Junichi Hashimoto
Life of this patent
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Abstract
In a semiconductor laser having a p-type cladding layer consisting of GaInP or AlGaInP, an operating voltage is decreased. In a semiconductor laser formed on a GaAs substrate and having a p-type cladding layer consisting of GaInP or AlGaInP and a p-type contact layer consisting of GaAs or GalnAs, p-type buffer layers are formed between the p-type cladding layer and the p-type contact layer, which consists of a compound containing both arsenic (As) and phosphorus (P) and having a medium bandgap between those of the two layers.
Claims9
A semiconductor laser comprising:
- a. an n-type GaAs substrate,
- b. an n-type cladding layer formed on said n-type GaAs substrate,
- c. an active region layer formed on said n-type cladding layer,
- d. a p-type cladding layer formed on said active region layer, said p-type cladding layer being fabricated from a first material selected from a group comprising GaInP and AlGaInP,
- e. a p-type buffer layer formed on said p-type cladding layer, said p-type buffer layer being fabricated from a second material selected from a material having a composition containing arsenic (As) and said first material used to fabricate said p-type cladding layer,
- f. a p-type contact layer formed on said p-type buffer layer, said p-type contact layer being fabricated from a third material which has a bandgap smaller than a bandgap of said second material used to fabricate said p-type buffer layer, said third material being selected from a group comprising GaAs and GaInAs, and
- g. electrodes formed on a lower surface of said n-type GaAs substrate and an upper surface of said p-type contact layer, respectively,
- wherein a composition ratio of said p-type buffer layer is changed such that the bandgap decreases from said p-type cladding layer to said p-type contact layer.
A semiconductor laser comprising:
- a. a p-type GaAs substrate,
- b. a p-type buffer layer formed on said p-type GaAs substrate directly or through a buffer underlayer, said p-type buffer layer consisting of a material having a composition containing arsenic (As) and phosphorus (P) and a bandgap larger than that of said p-type GaAs substrate,
- c. a p-type cladding layer formed on said p-type buffer layer, said p-type cladding layer consisting of a material of one of GaInP and AlGaInP which has a bandgap larger than that of said p-type buffer layer,
- d. an active region layer formed on said p-type cladding layer,
- e. an n-type cladding layer formed on said active region layer,
- f. an n-type contact layer formed on said n-type cladding layer, and
- g. electrodes formed on a lower surface of said p-type GaAs substrate and an upper surface of said n-type contact layer, respectively.
Dependencies are inferred from the claim text.