Shallow junction formation and low thermal budget control are important for advanced device manufacturing. Implant into silicide (IIS) method is a candidate to achieve both requirements. In this work we show that the high activation ability of the implant into nickel silicide method at low activated temperature is strongly related to the solid phase epitaxial regrowth (SPER) process. The SIMS, capacitance-voltage (C-V), four points probe (FPP), and current-voltage (I-V) measurements are combined to demonstrate that the SPER process of the IIS method is starting from the silicide/silicon (M/S) interface. The best N+/P interface is formed when SPER is complete. After SPER process finished, additional thermal budget may cause junction performance degradation at the temperature higher than 550 degrees C. (C) 2008 Elsevier B. V. All rights reserved.