Arrangement of silicon nano-dots along step edges of a Si(111) surface: STM investigation

Arrangement of silicon nano-dots along the step edges of a vicinal Si(111) surface was achieved. Silicon nitride islands were formed on a vicinal Si(l ll) surface, which was 1 degrees off toward the [(1) over bar(1) over bar2] direction, via a thermal nitridation reaction using N-2 gas. On this nitri ded surface, oxygen gas was dosed to induce a local selective etching of th e bare silicon area. The resultant surface showed a one-dimensional arrange ment of silicon nano-dots along the step edges of the silicon surface. The lateral size of the dot in the direction perpendicular to the step edges wa s restricted to the terrace width of the stepped Si(111) surface. This is e xplained in terms of the preferential growth of silicon nitride islands on the surface step edges, resulting in the apparent alignment of silicon nano -dots along the step edges of the vicinal Si(111) surface.