Fabrication of Schottky-Barrier-Oxide- Semiconductor Thin-Film Transistors via a Simple Aluminum Reaction Method

Abstract

In this work, we proposed a simple method for fabricating Schottky-barrier thin-film transistors (TFTs) with tailorable device characteristics. Through a simple post annealing process, an AlOx interlayer was formed between Cu/Al source/drain electrodes and the amorphous indium gallium zinc oxide (IGZO) layer, which induced the formation of a Schottky-barrier between Cu and the IGZO layer at the edge of the electrodes to modulate the carrier injection. Consequently, we found TFTs with different IGZO thicknesses presented notably different operation characteristics. When the thickness of the IGZO layer was 30 nm, the fabricated TFT behaved like a high mobility Ohmic-contact device, with an apparent field effect mobility as high as 82.9 cm2 V−1 s−1. After the thickness of the IGZO layer was reduced to 10 nm, the TFT worked like a Schottky-contact TFT, which exhibited a low saturation voltage of 2.3 V and a high output current of up to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$80~\mu \text{A}$ </tex-math></inline-formula> at <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{{\mathrm {GS}}} =20$ </tex-math></inline-formula> V.