Size and Thickness Effect on the Local Strain Relaxation in Patterned Strained Silicon-on-Insulator

Abstract

Strained silicon-on-insulator (sSOI) wafers with various strained-Si (sSi) layer thicknesses were fabricated by the Smart Cut technology. The strain relaxation by patterning into isolated sSOI device islands and high-temperature annealing is maximized in the absence of capping layers or any other precautions. No strain relaxation in unpatterned areas could be detected, and the strain relaxation of the patterned sSOI device islands occurred mainly from the edges of the device islands. The strain relaxation increases as the sSi layer thickness increases. The majority of strain was maintained for 15 nm sSOI film thickness after patterning and annealing at 900°C.