Simulation analysis of boron pocket deactivation in NMOS transistors with SPER junctions

We analyze the effects of junction formation by low-temperature solid phase epitaxial regrowth in NMOS transistors. Atomistic simulations indicate that the high concentration of Si interstitials associated with the end of range (EOR) defects favors the local formation of boron clusters just beyond the amorphous/crystalline interface, in agreement to sheet resistance measurements. Thus, EOR defects locally deactivate B in the NMOS pockets. These boron clusters start dissolution, and thus B reactivates, when the high Si interstitial supersaturation produced by the EOR defects decays close to the equilibrium value. This occurs when EOR defects dissolve or evolve to very stable configurations, such us dislocation loops.