Profiling of ultra-shallow complementary metal–oxide semiconductor junctions using spreading resistance: A comparison to secondary ion mass spectrometry

Abstract

Spreading resistance profiling (SRP) and secondary ion mass spectrometry (SIMS) were used to characterize ultra-shallow (<100 nm deep) doping profiles. For junctions below 100 nm, the sheet resistances determined from carrier concentrations calculated from spreading resistance data in the traditional manner were considerably greater than values measured by the variable probe spacing technique. A new model which includes the effect of a damaged layer on the beveled surface is presented which accounts for the discrepancy between the measured and calculated sheet resistances. A Poisson analysis (SRP2) of the measured SRP data show that the doping profile and on-bevel carrier concentration profile differ only slightly near the junction for the shallow, heavily doped layers considered in this study.