Qualification of spreading resistance probe operations

This article discusses the preliminary results obtained from an extensive spreading resistance probe (SRP) intercomparison conducted between 21 international laboratories with different levels of expertise both in the U.S. and in eight European countries. In the first phase, identical raw SRP model data and model calibration curves were sent around for six different structures. The carrier and resistivity profiles obtained from many different versions of software packages from three different manufacturers were analyzed. The observed variations are mainly dominated by radius variations and differences in applied mobility models. In the second phase, an extensive round robin was organized, involving the measurement of 22 separate samples including submicron source/drain and well implants and an ultrashallow sub-100 nm, 20 keV As implant. All samples were initially characterized by secondary ion mass spectrometry and four point probe mappings. The SRP repeatability and reproducibility for dose, sheet resistance, and junction depth obtained from a statistical analysis as defined by the International ISO 5725 standard are discussed as well as basic operational parameters such as bevel surface roughness, probe penetration, and bevel angle accuracy. All results indicate that there is a need for better international standardization of SRP operations. (C) 1998 American Vacuum Society.