Elastic silicon-film-based nanoshells: Formation, properties, and applications

Controllable formation and properties of solid single-crystal micro-and nanoshells of various shapes (tubes and spirals, vertically positioned rings and cylinders, and bent and trough-shaped cantilevers) are briefly reviewed, and new results are given. The shells and complicated structures of prescribed size and shape are formed with the use of elastic energy of initial strained SiGe/Si films of nanometer thickness and methods of highly selective and directed detachment of the films from the silicon substrates. It is experimentally demonstrated that the diameters of the fabricated SiGe/Si nanotubes are several times smaller than the values predicted by the continuum elasticity theory. The properties of the shells made of semiconductor and hybrid (metal-semiconductor and metal-dielectric-semiconductor) films and their applications in micro-and nanoscale electrical engineering are discussed.