Effect of Sb template layer on GaSb thin films grown on Si(111) substrate by molecular beam epitaxy

Abstract

AbstractGaSb thin films using an Sb template layer on Si(111) substrates were grown by MBE to investigate the effect of the Sb template on the crystalline quality of the GaSb films. Structural properties were compared with those of the GaSb films grown on Si(111) substrates using an AlSb initiation layer and a GaSb film directly grown on Si(111) substrate. For the GaSb thin films prepared using an Sb template layer, streaky RHEED patterns were observed throughout growth of GaSb layer and a typical surface RMS roughness value of 7.4 nm was obtained.The results of θ‐2θ scan XRD investigations indicated that GaSb film on Sb template is nearly unstrained. The φ‐scan XRD measurements with respect to {422} reflection peaks of GaSb films and Si(111) substrates did not show any sound evidence of alignment upon rotation by 30° and rather suggest two domain growth of the GaSb films. The smaller percentage of the domain which is rotated by 60° suggests that the GaSb film grown using an Sb template is more single crystal than the one grown using an AlSb initiation layer. These structural comparisons indicated that the Sb template layer is favorable in obtaining good GaSb epitaxial films. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)