Defect structure in selectively grown GaN films with low threading dislocation density
Defect structure in selectively grown GaN films with low threading dislocation density
复制标题
DOI：
10.1063/1.120044
复制
发表时间：
1997-10
影响因子：
4
通讯作者：
A. Sakai;H. Sunakawa;A. Usui
中科院分区：
文献类型：
--
作者：
A. Sakai;H. Sunakawa;A. Usui
利用透射电子显微镜（TEM）对氢化物气相外延（HVPE）选择性生长的GaN薄膜中的缺陷结构进行了表征。在该实验中，在已经通过金属有机物气相外延（MOVPE）在蓝宝石衬底上生长的SiO2条带图案化GaN层上实现生长。横截面TEM清楚地表明，在HVPE生长的薄膜厚度达到约5 μm之前，大多数位错（源自MOVPE生长层中垂直排列的穿透位错）在HVPE生长的薄膜中围绕SiO2掩模横向传播。这种传播方向的改变阻止了位错穿过薄膜到达表面区域，从而主要导致较厚薄膜中的穿透位错密度急剧降低。
We have characterized by transmission electron microscopy (TEM) defect structures in GaN films grown selectively in hydride vapor-phase epitaxy (HVPE). In this experiment, growth was achieved on SiO2-stripe-patterned GaN layers that had been grown by metalorganic vapor-phase epitaxy (MOVPE) on sapphire substrates. Cross-sectional TEM revealed unambiguously that most of the dislocations, which originated from threading dislocations vertically aligned in the MOVPE-grown layer, propagated laterally around the SiO2 mask in the HVPE-grown film before the film thickness amounted to about 5 μm. This change of the propagation direction prevented the dislocations from crossing the film to the surface region and thus principally led to a drastic reduction in the threading dislocation density in thicker films.