High-Resolution Characterization of Ultra-Shallow Junctions by Scanning Spreading Resistance Microscopy

摘要

To achieve high performance for ultra-shallow junction CMOSFETs, precise control of source/drain extension (SDE) and halo distribution is necessary, [1-4] which in turn requires precise and high spatial resolution two-dimensional (2D) characterization of carrier distributions. Although several 2D characterization methods exist, practical analysis in industry requires direct conversion of a wide range of carrier concentrations and efficient use of time for sample preparation. Scanning spreading resistance microscopy (SSRM) has been shown to be the most promising candidate for all these purposes, [5-7] However, the reproducibility and high spatial resolution of SSRM measurement still remain difficult to achieve with commercially available probes. One of the possible reasons is that a sufficiently stable contact between sample and probe has been difficult to control, and the wearing out effect of probes has also been pronounced when the measurement is performed in air.