Two-dimensional carrier profiling of advanced sub-micron silicon devices using Scanning Capacitance Microscopy

Abstract

Abstract With the continuing push for reduction in the device dimensions into the deep sub-u,m dimensions, the critical need for physical and electrical characterization on this sub-μ,m scale is evident. The National Technology Roadmap has identified need for two-dimensional (2D) dopant/carrier profiling with a spatial resolution of 10 nm. Though current techniques used for dopant profiling such as secondary ion mass spectroscopy (SIMS) and spreading resistance profiling (SRP) have a high sensitivity, these offer good resolution only in the depth direction. The spatial resolution in the lateral direction in these techniques is limited to several tens or hundreds of microns. To acheieve the required lateral spatial resolution different scanning probe based techniques have been explored. One of the most promising of these class of techniques is scanning capacitance microscopy (SCM). In SCM a conductive atomic force microscope (AFM) probe tip is scanned across the surface and simultaneously an a.c. bias is applied between the tip and the sample.