Design of Si surfaces for self-assembled nanoarchitecture

The final goal of nanostructure integration based on self-assembly is full-wafer design of whole atomic-level structures. Toward this goal, we must first be able to control atomic steps, reconstructed domains, surface strain, and atomic species. Atomic steps can be rearranged artificially in a large area using lithographic technique and we are now close to achieving complete control of step positions. Patterns of reconstructed domain regions can be ordered by self-organization. In nanostructure self-assembly, such as the coherently grown Ge quantum nanostructures on Si(0 0 1) and Si(1 1 3) surfaces, strain engineering is important for controlling position, shape, and distribution. Ordered Ge-island chains on Si(0 0 1) show that artificial strain distribution design is a powerful tool for nanostructure integration. Surface composition on SiGe mixed surfaces can be reversibly changed by hydrogen adsorption and desorption. These approaches to designing surface structures show that the bottom-up approach is a promising alternative in semiconductor integration technology.