Quantitative Interpretation of Scanning Capacitance Microscope Images as Two-Dimensional Dopant Profiles

Abstract

Abstract Scanning capacitance microscopy (SCM) is used as a qualitative analysis tool with multiple applications for failure analysis. SCM can measure the shape of dopant profiles, can ascertain if certain implants have been completed, can verify the conduction type of implanted regions, and can look for unexpected shorts or opens in doped regions of a device. To obtain quantitative two-dimensional dopant profiles from SCM images of silicon devices requires careful attention to the data acquisition conditions and processing of the measured SCM image using quantification software. This paper discusses the operational subtleties of the scanning capacitance microscope required to produce images amenable to quantitative interpretation as dopant profiles. Two approaches to quantitative dopant profile extraction are discussed: the calibration curve method and the regression method. The structure and use of the FASTC2D software for dopant profile extraction from SCM images developed at the National Institute of Standards and Technology is described. Finally, two-dimensional dopant profiles from some simple structures and a discussion of the quality of the extracted profiles are presented.