Low-Temperature Fabrication of Amorphous Zinc-Tin-Oxide Thin Film Transistors with In-Situ Annealing Process

This study analyzes the effect of heating during deposition on the electrical and material properties of zinc tin oxide (ZTO) thin film transistors (TFTs). Instead of post-deposition annealing (PDA) at more than 300 degrees C, the ZTO-TFTs were fabricated by heating the substrate to 150 similar to 200 degrees C with 0 similar to 20% of oxygen in chamber and low temperature PDA in air atmosphere. As a result, it was possible to fabricate devices that show similar electrical characteristics with mobilities of 5.8-27.1 cm(2) V-1 s(-1), I-on/I-off of 108, and subthreshold swing of 0.15 similar to 1.7 V dec(-1), while lowering the process temperature by more than 100 degrees C. We also proceeded to fabricate a device on polymer substrate, which is the ultimate goal of lowering the process temperature. ZTO-TFTs possessing transparency and flexibility were successfully fabricated on 125 mu m polyethylene naphthalate (PEN) substrates. They showed electrical properties with a mobility of 1.7 cm(2) V-1 s(-1), I-on/I-off of 10(8), and subthreshold swing of 0.39 V dec(-1). (c) 2017 The Electrochemical Society. All rights reserved.