Initial Stages of Interface Formation in the Si/Sn System

Group IV-IV heterostructures with Sn as one constituent have potentially important applications. We report on an investigation of the initial stages of interface formation for deposition of Sn on Si(100)2×1 and Si(111)7×7. We find that simple growth occurs up to a critical coverage θc. (α1.25×1015 cm-2), independent of temperature. Beyond θc. growth continues to be laminar for deposition at 150 K only, while island formation is observed at temperatures at and above room temperature. The Si(111)7×7 reconstruction seems unperturbed by Sn deposition at room temperature while the Si(100)2×1 begins to order. However, the reordering, a necessary condition for perfect growth, is incomplete.