title: Growth mode and defect evaluation of GaSb on GaAs substrate: a transmission electron microscopy study.
abstract: We use transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) techniques to confirm and analyze the interfacial misfit (IMF) and non-IMF growth modes for GaSb epilayers on GaAs substrates. Under optimized IMF growth conditions, only pure 90 degrees dislocations are generated along both [110] and [1-10] directions and located exactly at the epi-substrate interface, which leads to very low density of misfit dislocations propagating from the GaSb/GaAs interface along the growth direction, compared to the non-IMF growth condition. The mechanism of defect annihilation indicates that this IMF mergence process happens without formation of threading dislocations into the GaSb epilayer, which is a completely relaxed growth mode with extremely low defect density. Based on scanning several sets of wafer surfaces, plan-view TEM confirms that the misfit defect densities are estimated to be approximately 5 x 10(5) cm(-2) for IMF growth mode and approximately 10(9) cm(-2) for non-IMF growth mode.
authors.affiliation: Department of Earth and Planetary Sciences, University of New Mexico, Albuquerque, NM 87131, USA.
authors.forename: Shenghong
authors.initials: S
authors.lastname: Huang
authors.forename: Ganesh
authors.initials: G
authors.lastname: Balakrishnan
authors.forename: Diana L
authors.initials: DL
authors.lastname: Huffaker