INFLUENCE OF CARBON CONTAMINATION ON ETCHED GASB SUBSTRATE ON THE QUALITY OF MBE-GASB FILM AND ELECTRICAL-TRANSPORT THROUGH THE FILM AND THE SUBSTRATE

Undoped MBE-GaSb films were grown on undoped GaSb(100) substrates and the influence of carbon contamination on the etched GaSb substrate on the grown film were investigated. It was found that carbon contamination of the etched GaSb substrate was dependent on the chemical treatment method and produced stacking faults in the subsequent MBE growth of the GaSb film. Carbon contamination on the etched GaSb substrate degraded the quality of the GaSb film and affected ohmic characteristics between the film and the substrate. Substrate surface free of carbon contamination and thereby exhibitting no influence on the electrical transport through the film and the substrate could be reproducibly obtained by performing an oxide etch-off chemical treatment on the GaSb substrate.