Si(100)-(2×1)boron reconstruction: Self-limiting monolayer doping

Abstract

A (2×1) surface reconstruction distinct from the clean Si(100)-(2×1) surface is formed by depositing boron onto silicon in ultrahigh vacuum. Overgrowth of epitaxial silicon at low temperature preserves a (2×1) superstructure of substitutional boron. Hall-effect measurements at 4.2 K show complete electrical activity for boron coverages of 1/2 monolayer, but additional boron above 1/2 monolayer is not electrically active.