Publication Date:
2014-03-06
Description:
We carried out experiments and computational simulations in order to answer a yet unanswered question about a surface flattening mechanism of a [ 1 1 ¯ 0 3 ¯ ] -oriented GaN film consisting of faceted non-flat top twins. Our results revealed that an overgrowth of one variant of twins over the other, which was manifested only at a thickness larger than a few microns due to a slight asymmetric crystallographic tilt (1.0° ± 0.4°) of twins, played a key role in a surface flattening mechanism. In addition, we experimentally demonstrated that GaN grown on a SiO 2 - patterned m -plane sapphire substrate had no asymmetric tilt and that no surface flattening occurred.
Print ISSN:
0003-6951
Electronic ISSN:
1077-3118
Topics:
Physics