Maximizing uniaxial tensile strain in large-area silicon-on-insulator islands on compliant substrates

Recently we have demonstrated a process for generating uniaxial tensile strain in silicon. In this work, we generate uniaxially strained silicon and anisotropically strained silicon germanium on insulator with strain in both 〈100〉 and 〈110〉 in-plane directions. The strain is uniform over fairly large areas, and relaxed silicon-germanium alloy buffers are not used. The magnitude of uniaxial strain generated by the process is very dependent on the in-plane crystal direction, and can be modeled accurately using the known mechanical properties of silicon and germanium. A maximum uniaxial silicon strain of 1.0% in the 〈100〉 direction is achieved. Numerical simulations of the dynamic strain generation process are used to identify process windows for achieving maximum uniaxial silicon strain for different structural geometries.