Nucleation of c-Axis Screw Dislocations at Substrate Surface Damage during 4H-Silicon Carbide Homo-Epitaxy
Nucleation of c-Axis Screw Dislocations at Substrate Surface Damage during 4H-Silicon Carbide Homo-Epitaxy
复制标题
4H 碳化硅同质外延过程中衬底表面损伤处 c 轴螺旋位错的形核
DOI：
10.4028/www.scientific.net/msf.645-648.295
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发表时间：
2010
期刊：
影响因子：
--
通讯作者：
E. Sanchez
中科院分区：
文献类型：
--
作者：
M. Dudley;Ning Zhang;Yu Zhang;B. Raghothamachar;E. Sanchez
报道了在4 H-SiC CVD同质外延生长过程中，衬底表面划痕处位错成核的观察结果。与划痕相关的亚表面残余损伤被观察到充当外延层中的基面位错（BPD）、螺纹刃位错（TED）和螺纹螺位错（TSD）的成核位点。TED和BPD从注入到衬底表面的基面位错半环的表面交叉点复制。TSDs的成核机制，成核在相反的符号对，提出了一个模型，其中涉及过度生长的表面压痕与划痕在步进流生长。接近这些局部表面凹陷的原子台阶可以塌陷，产生一对相反符号的螺旋位错，其Burgers矢量大小等于塌陷期间产生的台阶位错的大小。
Observations of dislocation nucleation occurring at substrate surface scratches during 4H-SiC CVD homoepitaxial growth are reported. Sub-surface residual damage associated with the scratches is observed to act as nucleation sites for basal plane dislocations (BPDs), threading edge dislocations (TEDs) and threading screw dislocations (TSDs) in the epilayer. TEDs and BPDs replicate from the surface intersections of basal plane dislocation half-loops injected into the substrate surface. A model for the nucleation mechanism of TSDs, which nucleate in opposite sign pairs, is presented which involves overgrowth of surface indentations associated with the scratch during step flow growth. Atomic steps which approach these local surface indentations can collapse creating pairs of opposite sign screw dislocations which have Burgers vector magnitude equal to the magnitude of the step disregistry created during the collapse.