Two-Dimensional Simulation of Scanning Capacitance Microscopy Measurements of Arbitrary Doping Profiles

摘要

Accurate prediction of doping distributions in modern VLSI devices (e.g. shallow junctions) with TCAD tools represents a major challenge which requires the process simulation models to be accurately tuned on the basis of two-dimensional dopant profile measurements. Scanning capacitance microscopy is a scanning probe based technique which provides images with spatial resolution in the 10 nm range. The extraction of quantitative doping information from the raw experimental data requires a calibration procedure. Presently, most of the results are obtained either with a large reverse simulation effort or with a first-order data inversion procedure (direct inversion). The current assumption of the latter approach is the quasi-uniformity of the doping profile. The scope of the present paper is to investigate the limits of this simplified approach by two-dimensional simulations of SCM measurements.