Pattern-induced alignment of silicon islands on buried oxide layer of silicon-on-insulator structure

Abstract

Alignment control of Si islands thermally agglomerated on a buried ${\mathrm{SiO}}_2$ layer of a silicon-on-insulator (SOI) structure is reported. As a starting structure, a line-shaped (001) SOI layer is prepared using an electron beam lithography and a selective oxidation technique. Annealing in an ultrahigh vacuum, SOI line structure having submicron width and thickness of ∼3 nm is deformed into island arrays aligned along two edges of the line pattern. This pattern-induced alignment occurs independent of in-plane crystalline directions of the line pattern, while we have previously reported for unpatterned SOI that the island alignment is commonly observed along the 〈310〉 directions. It is indicated that the linewidth and the SOI thickness play key roles in changing alignment behavior from the crystalline directions to the line pattern directions.