Advances in SEM-based diffraction studies of defects and strains in semiconductors
Advances in SEM-based diffraction studies of defects and strains in semiconductors
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基于 SEM 的半导体缺陷和应变衍射研究进展
DOI：
10.1093/oxfordjournals.jmicro.a023810
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发表时间：
2000
期刊：
影响因子：
--
通讯作者：
A. Wilkinson
中科院分区：
文献类型：
--
作者：
A. Wilkinson
利用电子通道对比成像（ECCI）和电子背散射衍射（EBSD）两种基于扫描电子显微镜（SEM）的衍射技术，研究了生长在带有平台图案的Si衬底上的Si1-xGe(x)薄膜的晶格缺陷和局部弹性应变分布。ECCI技术允许在散装样品中成像错配位错。错配位错引起台地间和较宽台地平面区域应变的塑性松弛。在较窄的台地面上，消除台地侧面的侧向约束足以降低应力，从而抑制平行于紧密间隔的侧面的位错的传播。通过测量局部应变场变化引起的EBSD模式中两个带轴位置的微小变化，确定了构成描述长台地结构变形的广义平面应变张量的应变和旋转。该方法的应变灵敏度约为+/- 2 × 10（-4）。据报道，应变和旋转在几个维度的台地上的分布，在台地宽度与脱毛层厚度高和低的台地之间存在显著差异。
Two scanning electron microscope (SEM)-based diffraction techniques, i.e. electron channelling contrast imaging (ECCI) and electron back-scatter diffraction (EBSD) are used to study lattice defect and local elastic strain distributions in Si1-xGe(x) epilayers grown on Si substrates patterned with mesas. The ECCI technique allows the misfit dislocations to be imaged in bulk samples. The misfit dislocations caused plastic relaxation of the strain in planar regions between mesas and in the wider mesas. In the narrower mesas the removal of lateral constraint at the mesa side faces had reduced the stress sufficiently to suppress the propagation of dislocations parallel to the closely spaced side faces. The measurements of small changes in the positions of two zone axes in EBSD patterns caused by variations in the local strain field were used to determine the strains and rotations making up the generalized plane strain tensor describing the deformation in the long mesa structures. The strain sensitivity of the method was determined to be approximately +/- 2 x 10(-4). Distributions of strains and rotations across mesas of several dimensions are reported and differ significantly between mesa for which the mesas width to epilayer thickness is high and low.