Author:

Keywords:

Science & Technology, Technology, Physical Sciences, Engineering, Electrical & Electronic, Physics, Applied, Engineering, Physics, FinFET, flatband voltage, floating-body, gate leakage, WORK FUNCTION, GATE, METALS, 0906 Electrical and Electronic Engineering, Applied Physics, 4009 Electronics, sensors and digital hardware

Abstract:

Among the novel methods for flatband voltage (Vfb) measurement, we demonstrate that a gate-leakage-based technique is the most suitable for measuring Vfb in floating-body MOSFETs with ultrathin gate dielectrics. Starting from carrier separation experiments on planar MOSFETs, we show the universality of the gate conduction mechanism dependence on band alignment for both n- and p-FETs. We demonstrate that metrics based on the gate leakage (either its valence-band electron-tunneling component or its first-order derivative) reflect this dependence and allow equivalent-oxide-thickness-independent Vfb quantification. This dependence is also valid for high-k and capped gate dielectrics, whereas their gate conduction mechanism is dominated by direct tunneling. To illustrate, we extract gate-leakage-derivative-based metrics and measure Vfb of TaN and TiN gate electrodes in multiple-fin FETs integrated on silicon-on-insulator. © 2008 IEEE.