Structure of elastically strain-sharing silicon(110) nanomembranes

Nanomembranes composed of single-crystal, tensilely strained Si(110) and compressively strained SiGe(110) layers have been fabricated from silicon-on-insulator (SOI) substrates. Elastic strain sharing is demonstrated for a trilayer structure consisting of a 12 nm Si/80 nm Si_0.91Ge _0.09 film epitaxially grown on a 12 nm thick (110) oriented Si template layer that is subsequently released from its handle substrate. X-ray diffraction on the as-grown and released structures confirms a virtually dislocation-free membrane with a tensile strain of 0.23 ±0.02% in the Si(110) layers after release. Lower growth temperatures in molecular beam epitaxy allow for smoother growth fronts than are possible using chemical vapour deposition.