Residual carrier density in GaSb grown on Si substrates

The relationships between the densities of residual carriers and those of dislocation in GaSb films grown on Si substrates were investigated. Dislocation density was evaluated by cross-sectional transmission electron microscopy (TEM). The TEM images indicated that the dislocation density after a 5-μm-thick GaSb film was grown was below 1 × 108/cm2 although the density near the interface between the Si substrate and the GaSb film was about 3 × 109/cm2. Forming a dislocation loop by growing a thick GaSb layer may decrease the dislocation density. The density and mobility of the residual carrier were investigated by Hall measurement using the van der Pauw method. The residual carriers in GaSb grown on Si substrates were holes, and their densities decreased significantly from 4.2 × 1018 to 1.4 × 1017/cm3 as GaSb thickness was increased from 500 to 5500 nm.