Attofarad resolution capacitance-voltage measurement of nanometer scale field effect transistors utilizing ambient noise

A high resolution capacitance-voltage (C-V) characterization technique, enabling direct measurement of electronic properties at the nanoscale in devices such as nanowire field effect transistors (FETs) through the use of random fluctuations, is described. The minimum noise level required for achieving sub-aF (10^-18F) resolution, the leveraging of stochastic resonance, and the effect of higher levels of noise are illustrated through simulations. The non-linear ΔC_{gate-source/drain}-V_gate response of FETs is utilized to determine the inversion layer capacitance (C_inv) and carrier mobility. The technique is demonstrated by extracting the carrier concentration and effective electron mobility in a nanoscale Si FET with C _inv = 60aF.