Quantitative carrier concentration profiling by scanning resonance tunneling spectroscopy

Abstract

We investigated resonant electron tunneling peaks of individual C 60 molecules placed on oxidized silicon surfaces for uniform-doped wafers employing scanning tunneling microscopy and spectroscopy. Systematic increase of the C60-derived resonance peak energy with decrease of boron concentration and with the position in the depletion region of lateral p-n junctions both indicate that the peak energy can be used for quantitative evaluation of carrier density with high spatial resolution. The observed peak energy variation is supported by a calculation within a one-dimensional tunnel diode model. © 2005 American Institute of Physics.