Enhancement of Boron Activation in Shallow Junctions by Hydrogen

Abstract

ABSTRACTThe ability to activate greater amounts of dopants at lower temperatures is a persistent contingency in the continual drive for device scaling in Si microelectronics. We report on the effect of incorporating atomic hydrogen on the activation of implanted boron in shallow junctions. Hydrogen incorporation into the sample was carried out by exposure to an electron cyclotron resonance (ECR) hydrogen plasma. Enhanced activation was observed in hydrogenated samples for post-implantation annealing temperatures of 450°C and below, as measured by spreading resistance profilometry, and confirmed by identical boron atomic profile in hydrogenated and unhydrogenated samples. The enhancement in boron activation at lower temperature is attributed to the creation of vacancies in the boron-implanted region, the lattice-relaxation effect by the presence of atomic hydrogen, and the effect of atomic hydrogen on boron-interstitial cluster formation.