Investigation and Modeling of Boron Diffusion Reduction in Silicon by Flourine Implantation using Numerical Simulation

Abstract

With the increased interest in the use of fluorine co-implantation with boron for boron diffusion reduction in the fabrication of semiconductor devices, it is important to understand the mechanisms by which fluorine reduces transient enhanced diffusion (TED) and boron thermal diffusion. In this project, two special structures (structure A and structure B) are generated using process simulation to investigate the mechanism responsible for boron transient enhanced diffusion and the reduction of boron diffusion in silicon. Three F+ implantation energies of 20, 35 and 50 kev are used with same dose of 1×1015 / cm3 and follow by process diffusion at 900oC for 30 second. It is obtained that fluorine implantation has occasionally reduced boron transient enhanced diffusion caused by the boron implant ion. The role of the boron concentration, interstitials, vacancies, boron clusters and evolution of diffusion based different time of boron diffusion in silicon will be discussed. The simulations results suggest that fluorine is reducing the boron transient enhanced diffusion.