Atomic processes during Cl supersaturation etching ofSi(100)−(2×1)

Abstract

Supersaturation etching starts with Cl insertion into Si-Si bonds of Si(100) and leads to the desorption of ${\text{SiCl}}_{2}$ pairs. During etching, insertion occurs through a ${\text{Cl}}_{2}$ dissociative chemisorption process mediated by single dangling bond sites created by phonon-activated electron-stimulated desorption of atomic Cl. Based on scanning tunneling microscopy results, we identify a surface species, describe its involvement in supersaturation etching, and explore the energetics that control this process. In doing so, we show that insertion occurs at room temperature and that paired dangling bonds of bare dimers also mediate this process.