Characterization of Intrinsic Field-Effect Mobility in TFTs by De-Embedding the Effect of Parasitic Source and Drain Resistances

Abstract

Due to voltage drops across parasitic resistances in semiconductor devices, extracted performance parameters can be strongly dependent on the geometrical structure. In this letter, we report a characterization technique for the intrinsic field-effect mobility μ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">FEo</sub> in amorphous InGaZnO (a-IGZO) thin-film transistors (TFTs) by de-embedding the parasitic source and drain resistances <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">R</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">S</sub> and <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">R</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">D</sub> , respectively. We obtained the channel-length ( <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">L</i> ) -independent intrinsic field-effect mobility μ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">FEo</sub> from TFTs with various channel lengths on the same wafer. We expect that this characterization technique for <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">L</i> -independent intrinsic field-effect mobility is useful for accurate characterization, consistent modeling, and robust simulation of a-IGZO TFT circuits.