Reduction of boron thermal diffusion and elimination of boron transient enhanced diffusion in silicon by high energy fluorine implantation

Download

PDF Download (49Kb)

Description/Abstract

This letter investigates the effect of a deep F+ implant on the diffusion of boron in silicon. The effects on boron thermal diffusion and transient enhanced diffusion are separately studied by characterizing the diffusion of a buried boron marker layer in wafers with and without a 185keV, 2.3 x 10 15cm -2 F+ implants, the fluorine completely eliminates the transient, enhanced boron diffusion caused by the P+ implant, and in samples implanted with F+ only, the fluorine suppresses the boron thermal diffusion by 65 percent. These results are explained by the effect of the fluorine on the vacancy concentration in the vicinity of the boron profile.