Influence of Stacking Sequences and Lattice Parameter Differences on the Microstructure of Nonpolar AlN Films Grown on ($11\bar{2}0$) 6H-SiC by Plasma-Assisted Molecular Beam Epitaxy

概要

論文の詳細を見る
Thanks to close crystalline structures and low lattice mismatches, nonpolar ($11\bar{2}0$) 6H-SiC is expected to be a well-adapted substrate for the growth of nonpolar ($11\bar{2}0$) III–nitride films. We demonstrate that the local reproduction of the basal planes stacking induces the presence of numerous planar defects ($1.3\times 10^{6}$ cm-1) in AlN films deposited on ($11\bar{2}0$) 6H-SiC. Moreover, the tensile strain of AlN along the [0001] direction results in the cracking of the film for a thickness as low as 100 nm. This fragile plastic relaxation is favored because the only slip systems available for ductile plastic relaxation are pyramidal systems involving $a+c$ dislocations which have a high activation energy.
2010-04-25