GaSb films grown by vacuum chemical epitaxy using triethyl antimony and triethyl gallium sources

Abstract

GaSb films have been grown using triethyl-Ga and triethyl-Sb sources. In a hot-wall reaction chamber located within a high-vacuum chamber, multiple group-III alkyl molecular beams are directed into the reaction chamber onto wafers. The group-V molecules are injected from the perimeter of the reaction chamber and undergo molecular flow across the deposition zone. The utilization efficiency of the group-V source material is enchanced by the use of a thermal cracker located at the point of group-V gas injection and by the use of the hot-wall chamber. Both unintentionally doped p-type and Te doped n-type GaSb films are grown and characterized. GaSb p-n junction photodiodes are also reported with internal quantum yields as high as 85%. Unintentionally doped films were shown to have background carrier concentrations of 4×1016 cm3 by capacitance versus voltage measurement.