Design of oxide-based tunnel FETs using amorphous IGZO and p-type oxide semiconductors
Abstract
Thin-film transistors based on oxide semiconductors, such as amorphous InGaZnO4 (a-IGZO), are widely used in edge devices owing to their low power consumption. However, the fundamental limitation of the subthreshold swing (SS) hinders both high-speed response and further reduction in power consumption. In this study, we focus on the concept of the tunnel field-effect transistor (TFET), which can significantly reduce SS, and explore its application to a-IGZO-based transistors. To design the a-IGZO based TFETs, we experimentally determined the band diagrams of a-IGZO/SnO and a-IGZO/Nb-doped Bi2WO6 (Nb:BWO), considering depletion layers, using photoemission spectroscopy. Both heterojunctions exhibited type II band alignment, with the energy barriers between the conduction band minimum of a-IGZO and valence band maximum of SnO or Nb:BWO being 0.57 ± 0.05 and 1.72 ± 0.05 eV, respectively. Simulations based on these band diagrams demonstrated the on–off switching behavior of the a-IGZO/SnO TFET only, achieving a minimum SS value of 48 mV/dec with a 3 mm-thick a-IGZO, assuming an ideal interface. These results suggest that optimizing junction properties and material selection plays a crucial role in the realization of a-IGZO-based TFETs for enhanced energy efficiency in electronic devices.
Article Details
Journal Info
Journal of Applied Physics
American Institute of Physics
Authors (8)
Ryusuke Seino
Global Research and Development Center for Business by Quantum-AI technology (G-QuAT), National Institute of Advanced Industrial Science and Technology (AIST) 1 , Tsukuba, Ibaraki 305-8568,
Hidehiro Asai
Semiconductor Frontier Research Center, National Institute of Advanced Industrial Science and Technology (AIST) 3 , Tsukuba, Ibaraki 305-8568,
Ichiro Takakuwa
Global Research and Development Center for Business by Quantum-AI technology (G-QuAT), National Institute of Advanced Industrial Science and Technology (AIST) 1 , Tsukuba, Ibaraki 305-8568,
Shutaro Asanuma
Semiconductor Frontier Research Center, National Institute of Advanced Industrial Science and Technology (AIST) 3 , Tsukuba, Ibaraki 305-8568,
Yoshihiro Nemoto
Research Network and Facility Services Division, National Institute for Materials Science 4 , Tsukuba, Ibaraki 305-0047,
Yuki Nishimiya
Research Network and Facility Services Division, National Institute for Materials Science 4 , Tsukuba, Ibaraki 305-0047,
Keishi Nishio
Department of Materials Science and Technology, Tokyo University of Science 2 , Katsushika, Tokyo 125-8585,
Makoto Minohara
Global Research and Development Center for Business by Quantum-AI technology (G-QuAT), National Institute of Advanced Industrial Science and Technology (AIST) 1 , Tsukuba, Ibaraki 305-8568,