Defects in m-plane ZnO epitaxial films grown on (112) LaAlO3 substrate

Abstract

The crystallographic orientations of m-plane ZnO on (112) LaAlO3 (LAO) substrate are [(1) over bar2 (1) over bar0](ZnO)parallel to[11 (1) over bar](LAO) and [0001](ZnO)parallel to[(1) over bar 10](LAO). The defects in m-plane ZnO have been systematically investigated using cross section and plan-view transmission electron microscopy (TEM). High-resolution TEM observations in cross section show misfit dislocations and basal stacking faults (BSFs) at the ZnO/LAO interface. In the films, threading dislocations (TDs) with 1/3 < 11 (2) over bar0 > Burgers vectors are distributed on the basal plane, and BSFs have 1/6 < 20 (2) over bar3 > displacement vector. The densities of dislocations and BSFs are estimated to be 5.1 x 10(10) cm(-2) and 4.3 x 10(5) cm(-1), respectively. In addition to TDs and BSFs, plan-view TEM examination also reveals that stacking mismatch boundaries mainly lie along the m-planes and they connect with planar defect segments along the r-planes. (C) 2011 American Vacuum Society. [DOI: 10.1116/1.3539046]