Carbon doped GaAsSb suitable for use in tunnel junctions of long-wavelength VCSELs
AssigneeFinisar Corporation
InventorHoki Kwon
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Abstract
GaAs(1−x)Sbx layers are grown by MOCVD. For lattice matching with InP, x is set to 0.5, while beneficial alternatives include setting x to 0.23, 0.3, and 0.4. During MOVCD, TMGa (or TEGa), TMSb, and AsH3 (or TBAs) are used to fabricate the GaAs(1−x )Sbx layer. Beneficially, the GaAs(1−x)Sbx layer's composition is controlled by the ratio of As to Sb. The MOCVD growth temperature is between 500° C. and 650° C. The GaAs(1−x)Sbx layer is beneficially doped using CCl4 or CBr4. A heavily doped GaAs(1−x)Sbx layer can be used to form a tunnel junction with n-doped layers of InP, AlInAs, or with lower bandgap materials such as AlInGaAs or InGaAsP. Such tunnel junctions are useful for producing long wavelength VCSELs.
Claims20
A method of fabricating GaAs(1−x)Sbx layers, comprising:
- locating a substrate in an MOCVD chamber;
- setting a temperature of the MOCVD chamber between 500° C. and 650° C.;
- and
- growing GaAs(1−x)Sbx on the substrate using an MOCVD process in which a source of Ga, a source of Sb, and a source of As are present.
A tunnel junction having of a p-doped GaAs(1−x)Sbx layer.
A vertical cavity surface emitting laser, comprising:
- an active region having a plurality of quantum wells, and
- a tunnel junction over said active region, wherein said tunnel junction includes a GaAs(1−x)Sbx layer.
Dependencies are inferred from the claim text.