Concentration profiles of antimony-doped shallow layers in silicon

Abstract

Antimony implants at 40 keV and at a dose of 4 × 1014 cm-2 have been characterized for their potential use in n-type shallow junction formation. The electrical characterization was done using sheet resistivity and Hall effect measurements. High electrical activities (>80%) and low sheet resistance values (<200 Ω/□) were obtained for annealing temperatures below 800 °C. A novel differential Hall effect technique was used to obtain doping profiles at a depth resolution down to 1 nm, with a comparison made between these and Rutherford backscattering (RBS) measurements of the atomic profile as a function of annealing temperature. The antimony shows insignificant diffusion for annealing temperatures of 800 °C and below, with junction depths of about 60 nm. Electrical activation correlates well with the substitutional fraction of antimony determined by RBS.