Figure 4

Biaxial modulus and strain distribution in a Si(110) trilayer membrane. (a) The modulus, M, for Si (solid line) and Ge (dashed line) as a function of in-plane direction on the (110) surface. The inset shows the atomic arrangement in the (110) plane. The crystallographic and elastic symmetry is twofold for the (110) surface orientation. (b) In-plane strain distributions in the balancing layers of trilayer NMs after elastic strain sharing for biaxially anisotropic balancing layers with a biaxially anisotropic stressor layer, corresponding to the Si(110) trilayer. Each curve represents a different thickness ratio between the outer balancing Si layers and the SiGe stressor layer: dotted line = 0.1, solid line = 1, and dashed line = 10. The mismatch strain in the system is shown as the red line; it corresponds to the strain in the stressor layer before strain sharing occurs and has the opposite sign as the strain transferred to the outer balancing layers. The radial distance to any curve is the magnitude of the strain in that direction. From ref[28].