Furnace and Rta Injection of Point Defects into CVD-Grown B Doped Si and SiGe

Abstract

AbstractThe diffusion of B in Si and SiGe under the influence of point defect injection by Rapid Thermal Anneal (RTA) and conventional furnace anneal is studied in this work. B-doped regions in SiGe and Si were grown by LPCVD, and point defects were injected by RTA or furnace annealing bare, Si3N4 or SiO2 + Si3N4 covered samples in an oxygen atmosphere. Self-interstitial defects will be injected into bare Si while vacancy defects will be injected into Si3N4 covered samples, and inert annealing will occur in SiO2 + Si3N4 covered samples. The annealed and asgrown profiles were determined using SIMS analysis, and the diffusivities extracted by direct comparison of the profiles. Both interstitials and vacancies were injected during furnace annealing of SiGe, as demonstrated by the respective enhancement and retardation of the B diffusion. Enhanced B diffusion in SiGe was observed even for 5 s RTA at 1000°C, with an enhancement factor of ∼2.5. The B in Si diffusivity enhancement for interstitial injection by RTA oxidation was found to be a factor of ∼3 compared to inert anneals, close to the factor for SiGe.