Nanostructure Self-Organization by Controlling Surface and Interface Strain

Abstract

Self-organization of nanostructures on semiconductor surfaces is attractive to the researchers of future Si integration technology because it is free from the size and the writing-speed limitations in lithography. In the case of coherently grown Ge nanostructures on Si surfaces, control of the strain field will be a key issue in the integration of well-defined and well-arranged nanostructures. The strain effect has a variety of aspects for self-organized Ge nanostructures on Si. Its magnitude determines the size and its symmetry modifies the shape. The strain distribution influences the nanostructure nucleation sites. Since the coherently grown Ge nanostructures induce strain on the substrate surface, interaction between the nano-structures are generated through the substrate strain. In this review, we describe strain engineering on Si substrates including artificial control of the strain distribution using buried oxide inclusions. Strain symmetry effect and interaction between the nanostructures are well demonstrated in Ge nanowires grown on Si(113).