In situ monitoring of step arrays on vicinal silicon (100) surfaces for heteroepitaxy.

Abstract

Ordered step arrays on vicinal Si(100) surfaces have been observed with use of reflection high-energy electron diffraction (RHEED). For a 3\ifmmode^\circ\else\textdegree\fi{} misorientation toward a 〈100〉 direction, a stable single-layer step structure is observed. Evidence of a kinked step structure is found for the misorientation toward 〈100〉, with one of the samples showing randomly spaced kinks, and others having regularly spaced kinks along the step edges. For misorientations of up to 3.7\ifmmode^\circ\else\textdegree\fi{} toward a 〈110〉 direction, a step-induced structure which becomes more pronounced for higher misorientation angles is observed in the RHEED patterns. The RHEED observations indicate a transition from single-layer to double-layer steps as the tilt angle toward 〈110〉 is increased.