Boron Induced Dislocations in Silicon

Abstract

Electron microscopy, x‐ray diffraction, and chemical etch techniques have been used to study the induction of dislocations in silicon by boron.Boron at low doping levels clusters in silicon to form highly strained vacancy regions. As the doping level is raised, the clusters condense into dislocation loops. As the doping level is increased, loop formation increases. The silicon between these point defects contracts until at a boron level of about 8×1018 atoms cm−3 the lattice stress is sufficient to induce edge dislocation generation from loop interaction. As the dislocation density increases the lattice strain is relieved and the lattice constant approaches that of a Vegard alloy.