Growth and properties of GaSb and Al/sub x/Ga/sub 1-x/Sb layers by MOCVD

Abstract

A study of structural, electrical and optical properties of GaSb and Al/sub x/Ga/sub 1-x/Sb (0.05/spl les/x/spl les/0.25) grown by metalorganic chemical vapour deposition on GaAs, GaSb and Ge substrates using TMAl, TMGa, and TMSb is reported. The optimum growth window established for GaSb growth (temperature 540/spl deg/C and V/III=0.72) is significantly different from optimal growth parameters for AlGaSb layers. Higher V/III ratios and higher temperatures are required to protect the surface morphology of AlGaSb. All Al/sub x/Ga/sub 1-x/Sb in the investigated composition range 0.05/spl les/x/spl les/0.25 were grown at 580/spl deg/C and 800/spl deg/C and V/III ratio=3 and are characterized by excellent, smooth morphology, very high optical transmission and electrical parameters comparable with the best reported for this type of layer.