Profiling of ultrashallow junctions

Ultrashallow profiles challenge the capabilities of all characterization te chniques. In this article, three diagnostic techniques are tested, secondar y ion mass spectrometry (SIMS), capacitance-voltage (C-V) profiling and spr eading resistance analysis (SRA). SIMS is used to measure the impurity conc entration profiles, C-V is used to measure carrier concentration profiles d irectly and SRA is used to measure resistivity profiles, from which carrier concentrations can be derived. Both SIMS and SRA are calibrated techniques that relate the measured parameter to concentration or resistivity via cal ibration standards. C-V derives the carrier concentration directly through a mathematical model and calculation. Some of the assumptions, procedures, and limitations of these three techniques for ultrashallow profiles are rev iewed and discussed. For this article these diagnostic techniques were used to examine six wafers that had been plasma doped followed by a rapid therm al anneal and three wafers that had been beamline implemented followed by a soak anneal. (C) 2000 American Vacuum Society. [S0734-211X(00)00201-3].