Arsenic Junction Thermal Stability and High-Dose Boron-Pocket Activation During SPER in nMOS Transistors

In this letter, thermal stability of arsenic (As) junctions formed by solid-phase epitaxial regrowth and their impact on device performance are investigated. If the temperature does not exceed 800 degC, a 35% junction sheet-resistance improvement over the conventional rapid thermal anneal is observed. The overlap junction resistance is not degraded and transistors, processed exclusively with lowly doped drain junctions, show a significant performance gain. High boron (B)-pocket dose leads to good transistor short-channel effect control, overcoming the B deactivation issue. The impact of B-pocket-related counterdoping and channel-mobility degradation on device characteristics are investigated. In the presence of heavily doped substrates, band-to-band tunneling is the dominant mechanism driving the reverse-bias junction leakage and is higher than the trap-assisted tunneling contribution related to the end-of-range defects