Hole mobility degradation was studied in high-dose boron-implanted ultra-shallow junctions containing high concentrations of boron-interstitial clusters, combining an empirical method based on the self-consistent interpretation of secondary-ion-mass spectrometry and Hall measurements and liquid-nitrogen to room temperature hole mobility measurements. It was found that boron-interstitial clusters acted as independent scattering centers which had a strong impact on hole mobility in addition to the other scattering mechanisms such as lattice and impurities scattering. A mobility degradation coefficient α was introduced, which gave information on the mobility degradation level in the analyzed junctions. In the case of very high concentrations of boron-interstitial clusters (containing a boron density up to 8 x 1014/cm2), measured hole mobilities were found to be ∼40% lower than corresponding theoretical values. boron-interstitial cluster dissolution through multiple Flash anneals at high temperature (1300C) reduced the observed mobility degradation.

Influence of Boron-Interstitials Clusters on Hole Mobility Degradation in High Dose Boron-Implanted Ultrashallow Junctions. F.Severac, F.Cristiano, E.Bedel-Pereira, P.F.Fazzini, J.Boucher, W.Lerch, S.Hamm: Journal of Applied Physics, 2010, 107[12], 123711