High-resolution cross-sectional imaging of MOSFETs by scanning resistance microscopy

The authors present high-resolution (/spl ap/40 nm) Scanning Resistance Microscopy (SRM) images of MOSFET cross sections taken with commercially available boron-doped diamond tips. The diamond tips were found to offer significant improvement in resolution over metal tips. The SRM profiles using diamond tips can delineate the source/drain regions as well as the lightly-doped drains. Furthermore, the SRM profiles allow delineation between silicide and polysilicon on the gate, as well as delineation between the silicide and diffusion in the source/drain regions.