P‐1.1: Characterization of the Off‐State Current of an Elevated‐Metal Metal‐Oxide Thin‐Film Transistor

Abstract

Without employing an unconventional thin‐film transistor (TFT) with excessively wide effective channel width and offset source/drain electrodes, an improved methodology and circuit are applied to measuring the off‐state current (Ioff) of elevated‐metal metal‐oxide (EMMO) TFTs built on indium‐gallium‐zinc oxide, with or without fluorination. Ioff of around mid‐10−18 A/μm has been obtained, with the value slightly lower for an EMMO TFT with a fluorinated channel.

P‐1.2: All‐Oxide Thin‐Film Transistors for Low‐Voltage‐Operation Circuits

“…Compared with the normally-on devices, the normallyoff devices suffer an Ion reduction by ~3 times, but their Id@0 V is significantly decreased by at least two orders of magnitude at the same time. Therefore, the practical on-off ratio reaches as high as ~10 6 , indicating that the one-volt operation with no need for negative electric levels is feasible. The key electrical parameters of both normally-off and normally-on all oxide devices under the one-volt operation are summarized in Table 1.…”

“…The on-off ratio is directly associated with not only the Ion but also the Ioff. If MO TFTs exhibit an Ioff-level drain current (Id) (i.e., below the measurement limit of a typical semiconductor parameter analyzer [6]) at zero-volt gate bias (Vgs), it should not be difficult to operate these devices at a low voltage. Top-gated hybrid-phase ITO-stabilized ZnO TFTs have been reported with a high field-effect mobility (µfe, ~18 cm 2 /Vs) and a steep subthreshold swing (SS, <0.1 V/decade), a noise-level Ioff (<10 fA) after being capped by stacked PECVD SiO2 GIs [7] and transparent ITO gates [8].…”

An Integrated Analog Front‐End System on Flexible Substrate for the Acquisition of Bio‐Potential Signals

“…The actual resistance of a diode-connected TFT is correlated with the off-state leakage current of the TFT. A W-normalized leakage current of less than 10 −18 A μm −1 has been reported, [36] an exceptionally low value. The dependence of V P − P and V BIAS on V ON are displayed in Figure 3f, showing more deterioration of the former with more negative V ON , thus highlighting again the advantage of an enhancement-mode IGZO:F TFT over a depletion-mode IGZO TFT.…”