Direct observation of recombination-enhanced dislocation glide in heteroepitaxial GaAs on silicon
Direct observation of recombination-enhanced dislocation glide in heteroepitaxial GaAs on silicon
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DOI：
10.1103/physrevmaterials.2.081601
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发表时间：
2018-08-09
影响因子：
3.4
通讯作者：
Mukherjee, Kunal
中科院分区：
文献类型：
--
作者：
Callahan, Patrick G.;Haidet, Brian B.;Mukherjee, Kunal
我们用电子束在室温下用电子沟道衬底成像(ECCI)在硅衬底上诱导并直接观察到应变的GaAs薄膜中的位错滑移。由于阴极生成的电子空穴对在位错处的复合，降低了滑动的Peierls势垒，从动力学上促进了这种脆性材料的塑性行为。砷化镓薄膜中的高残余应变提供了运动的总驱动力。通过跟踪高空间和时间分辨率的单个线位错，研究了各种以前不可访问的位错相互作用的动力学。ECCI技术具有固有的高分辨率，并在方便的扫描电子显微镜环境中进行。此快速通信中描述的结果和方法有助于深入了解硅上具有重要技术意义的III-V器件以及其他不匹配异质外延系统中的位错过滤过程和故障机制。
We use an electron beam to induce and directly observe dislocation glide in strained GaAs thin films on silicon substrates at room temperature using electron channeling contrast imaging (ECCI). Plastic behavior in this brittle material is kinetically facilitated by a lowering of the Peierls barrier for glide due to recombination of cathodogenerated electron-hole pairs at dislocations. The high residual strain in the GaAs film provides the overall driving force for motion. The dynamics of a variety of previously inaccessible dislocation interactions are studied by tracking individual threading dislocations with high spatial and temporal resolution. The ECCI technique has an inherently high resolution and was conducted in a convenient scanning electron microscope environment. The results and methods described in this Rapid Communication provide insight into dislocation-filtering processes and failure mechanisms in technologically important III-V devices on silicon, as well as other mismatched heteroepitaxial systems.