Presentation Information
[3F04]Real-time resistance measurements in multilayer oxide thin films and characterization of thin-film transistors using Al2O3/ZnO multilayers for flexible device applications
*Kensuke Nakata1, Kaiko Yuge1, Hideo Wada1, Masatoshi Koyama1, Akihiko Fujii1, Toshihiko Maemoto1 (1. Nanomaterials Microdevices Research Center, Osaka Institute of Technology)
Real-time resistance measurements using multilayers of ZnO and Al2O3 were performed to elucidate a mechanism of performance enhancement of thin-film transistors with layers of oxide semiconductors. We focused on resistance changes in the stacked structure formed by depositing Al2O3 on the ZnO channel. Initially, the resistance of a single layer ZnO film before Al2O3 deposition was 4.65 kΩ. Upon initiating the Al2O3 deposition, the resistance decreased rapidly. Five minutes into the deposition process, the resistance decreased by 50%, and after ten minutes, it decreased by approximately 60%. This significant reduction in resistance suggests an increase in carrier density due to the high-energy Al2O3 particles dislodging adsorbed molecules at the Al2O3/ZnO interface, thereby creating O2 vacancies and other donor-type defects in the ZnO. Furthermore, the difference in band offsets between Al2O3 and ZnO at the interface suggests the formation of a quasi-two-dimensional electronic layer.