Using sulfide treatment to improve performance of GaSb/GaInAsSb/GaAlAsSb photodiode heterostructures for spectral range, of 1.7-2.5 /spl mu/m

Abstract

We have investigated passivation of GaSb and its quaternary GalnAsSb, and GaAlAsSb alloys in Na/sub 2/S and (NH/sub 4/)/sub 2/S water solutions. It has been found that these semiconductors are etched in the used sulfide solutions. We have found the etching rates and kinetics of the etching processes. Basing on the obtained results we have determined optimal technological conditions for the passivation of GaSb-substrate before liquid phase epitaxy growing of the quaternary layers. The layers of the grown heterostructures have been shown a small lattice mismatch and have exhibited a good abruptness interface. We have also used the sulfide treatment to passivate the side surface GaSb/GaInAsSb/GaAlAsSb photodiode heterostructures. Reduction of reverse dark current by a factor of 2-10 times was achieved.