Two-dimensional dopant profiling by electrostatic force microscopy using carbon nanotubemodified cantilevers

Abstract

A two-dimensional (2D) dopant profiling technique is demonstrated in this work. We applya unique cantilever probe in electrostatic force microscopy (EFM) modified by theattachment of a multiwalled carbon nanotube (MWNT). Furthermore, the tip apex of theMWNT was trimmed to the sharpness of a single-walled carbon nanotube (SWNT). Thisultra-sharp MWNT tip helps us to resolve dopant features to within 10 nm in air, whichapproaches the resolution achieved by ultra-high vacuum scanning tunnelling microscopy(UHV STM). In this study, the CNT-probed EFM is used to profile 2D buried dopantdistribution under a nano-scale device structure and shows the feasibility of devicecharacterization for sub-45 nm complementary metal–oxide–semiconductor (CMOS)field-effect transistors.