Role of surface steps in the arrangement of silicon nano-dots on a vicinal Si(111) surface: Scanning tunneling microscopy investigation

Abstract

In situ scanning tunneling microscopy characterization of step bunching on miscut Si (111) surfaces in fluoride solutions J. Appl. Phys. 85, 1545 (1999); 10.1063/1.369285 Nanometer scale selective etching of Si(111) surface using silicon nitride islands Evolution of surface morphology in the initial stage of nitridation of the Si(111)-7×7 surface by nitrogen ionsWe have investigated the role of surface steps in the arrangement of silicon nano-dots on a vicinal Si͑111͒ surface by scanning tunneling microscopy. Nanometer sized silicon nitride islands were formed on a vicinal Si͑111͒ surface, which was 1°off toward ͓1 1 2͔ direction, via thermal nitridation using N 2 gas. On the nitrided surface, oxygen gas was dosed to induce a local selective etching of bare silicon using the silicon nitride islands as masks. The resultant surface showed one-dimensional arrangement of silicon nano-dots along the step edges of silicon surface. The lateral size of the dot in the direction perpendicular to the step edges was restricted to the terrace width of the stepped Si͑111͒ surface. We consider that the preferential growth of silicon nitride islands on the edges of single height steps is responsible for the arrangement of silicon nano-dots along the step edges of the 1°off vicinal Si͑111͒ surface.

Structure of steps on As-passivated Si(111):Ab initiocalculations and scanning tunneling microscopy

“…A recent study of Si self-assembly at steps on clean Si͑111͒7 ϫ 7, 18,19 shows a temperature dependence of the step-induced structures: Growth temperatures below 300°C lead to Si atomic wires parallel to the steps, whereas at temperatures above 400°C, a periodic arrangement of Si clusters along the steps is observed. The stability of steps on the clean Si͑111͒2 ϫ 1 has been investigated.…”