Self-aligning of self-assembled Ge islands on Si(001)

The position of Ge islands formed on Si substrates by self-assembly can be determined by adjacent lithographically defined features. Islands tend to form near the edges of narrow Si lines defined by oxide isolation and conventional selective Si epitaxial deposition, offering the possibility of forming small device features without fine lithography. Multiple rows of islands can form on wider lines. The alignment is probably caused by easier nucleation on shallow facets; therefore, the position of the Ge islands can be influenced by controlling the shape of the underlying Si surface.