硅蹼中位错和层错的X射线貌相研究

利用X射线投影貌相术观察和分析了硅蹼中的位错和层错。在生长态硅蹼中,除观察到柏氏矢量为1/2<110>的刃型、螺型与60°全位错以及柏氏矢量为1/6<112>的Shockley刃型半位错外,还观察到平行于硅蹼表面的大面积层错和蹼中的60°,30°Shockley半位错。位错在热处理过程中运动并发生位错反应形成近六角形的位错网络。热处理改变生长态硅蹼中层错的组态和衬度,并由于杂质聚集破坏了Shockley半位错的消象法则。还观察到层错象中的位错。对所观察的结果都分别作了分析和简要的讨论。关键词：

X-RAY TOPOGRAPHIC STUDY OF DISLOCATIONS AND STACKING FAULTS IN SILICON WEB DENDRITES

Dislocations and stacking faults in silicon webs were observed and analysed by means of X-ray projection topographic method. Large area stacking faults parallel to the web surface have been found in as-grown specimens. In addition to the edge-, screw-, and 60°-type total dislocations with Burgers vector 1/2<110>, and edge-type Shockley partial dislocations with Burgers vector 1/6<112>, 30°- and 60°-type Shockley partial dislocations with Burgers vector 1/6<112> have also been discovered in the webs. These total dislocations move during heat treating at high temperatures and interact with other ones to form nearly hexagonal dislocation networks. Several dislocation reactions in a single slip plane have been found. The configuration and contrast of stacking faults in as-grown webs were changed by high temperature annealing. That can be explained by the moving of extended dislocation pairs, and the overlapping of stacking faults with each other in different layers. The extinction rule of image of Shockley partial dislocations was invalidated by the presence of impurity segregations. Dislocations within the stacking fault image were also observed. The experimentally observed results were analysed and discussed briefly.