title: Elastically relaxed free-standing strained-silicon nanomembranes.
abstract: Strain plays a critical role in the properties of materials. In silicon and silicon-germanium, strain provides a mechanism for control of both carrier mobility and band offsets. In materials integration, strain is typically tuned through the use of dislocations and elemental composition. We demonstrate a versatile method to control strain by fabricating membranes in which the final strain state is controlled by elastic strain sharing, that is, without the formation of defects. We grow Si/SiGe layers on a substrate from which they can be released, forming nanomembranes. X-ray-diffraction measurements confirm a final strain predicted by elasticity theory. The effectiveness of elastic strain to alter electronic properties is demonstrated by low-temperature longitudinal Hall-effect measurements on a strained-silicon quantum well before and after release. Elastic strain sharing and film transfer offer an intriguing path towards complex, multiple-layer structures in which each layer's properties are controlled elastically, without the introduction of undesirable defects.
authors.affiliation: University of Wisconsin-Madison, Madison, Wisconsin 53711, USA.
authors.forename: Michelle M
authors.initials: MM
authors.lastname: Roberts
authors.forename: Levente J
authors.initials: LJ
authors.lastname: Klein
authors.forename: Donald E
authors.initials: DE
authors.lastname: Savage
authors.forename: Keith A
authors.initials: KA
authors.lastname: Slinker
authors.forename: Mark
authors.initials: M
authors.lastname: Friesen
authors.forename: George
authors.initials: G
authors.lastname: Celler
authors.forename: Mark A
authors.initials: MA
authors.lastname: Eriksson
authors.forename: Max G
authors.initials: MG
authors.lastname: Lagally