Vaudin M D, Osborn W A, Friedman L H, Gorham J M, Vartanian V, Cook R F
Materials Measurement Science Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA.
Materials Measurement Science Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA.
Ultramicroscopy. 2015 Jan;148:94-104. doi: 10.1016/j.ultramic.2014.09.007. Epub 2014 Sep 30.
Patterned SiGe thin film structures, heteroepitaxially deposited on Si substrates, are investigated as potential reference standards to establish the accuracy of high resolution electron backscattered diffraction (HR-EBSD) strain measurement methods. The proposed standards incorporate thin films of tetragonally distorted epitaxial Si₁-xGex adjacent to strain-free Si. Six films of three different nominal compositions (x=0.2, 0.3, and 0.4) and various thicknesses were studied. Film composition and out-of-plane lattice spacing measurements, by x-ray photoelectron spectroscopy and x-ray diffraction, respectively, provided independent determinations of film epitaxy and predictions of tetragonal strain for direct comparison with HR-EBSD strain measurements. Films assessed to be coherent with the substrate exhibited tetragonal strain values measured by HR-EBSD identical to those predicted from the composition and x-ray diffraction measurements, within experimental relative uncertainties of order 2%. Such films thus provide suitable prototypes for designing a strain reference standard.
对异质外延沉积在硅衬底上的图案化硅锗薄膜结构进行了研究，将其作为建立高分辨率电子背散射衍射（HR-EBSD）应变测量方法准确性的潜在参考标准。所提出的标准包括与无应变硅相邻的四方畸变外延Si₁-xGex薄膜。研究了三种不同标称成分（x = 0.2、0.3和0.4）和不同厚度的六片薄膜。分别通过X射线光电子能谱和X射线衍射进行的薄膜成分和面外晶格间距测量，提供了薄膜外延的独立测定以及四方应变的预测，以便与HR-EBSD应变测量进行直接比较。经评估与衬底相干的薄膜，其通过HR-EBSD测量的四方应变值与根据成分和X射线衍射测量预测的值相同，在约2%的实验相对不确定度范围内。因此，这类薄膜为设计应变参考标准提供了合适的原型。
