Reliability improvement of InGaO<i> <sub>x</sub> </i> FETs by adding Zn in atomic layer deposition process
Abstract We fabricated nanosheet oxide semiconductor FETs with InGaZnO x (IGZO) channel grown by thermal atomic layer deposition (ALD) process. The effects of annealing, channel thickness, and composition on performance and reliability were systematically investigated. IGZO FETs achieved normally-off operation with positive threshold voltage ( V th ) while maintaining high mobility compared to InGaO x (IGO) FETs. The devices showed thermal stability up to 400 °C post-deposition annealing, compatible with BEOL process. Excess oxygen is a unique issue in ALD by oxygen-rich chemical reaction process compared to sputtering. The positive bias stress reliability issue in thin channel IGO FETs caused by excess oxygen was mitigated by adding Zn. This study can provide an insight for designing IGO-based FETs in terms of composition and channel thickness optimization for 3D LSI applications.
Authors
- Kota Sakai
- Takuya Saraya (ORCID: https://orcid.org/0000-0002-3796-7747)
- Yuki Itoya (ORCID: https://orcid.org/0009-0001-9105-5407)
- Masaharu Kobayashi (ORCID: https://orcid.org/0000-0002-7945-6136)
- Sung-Hun Kim (ORCID: https://orcid.org/0000-0002-3522-7307)
- Toshiro Hiramoto (ORCID: https://orcid.org/0000-0001-9469-2631)
- Kaito Hikake (ORCID: https://orcid.org/0009-0002-1311-4763)
Institutions
- Bunkyo University (JP)
- The University of Tokyo (JP)
Publication Details
- Journal
- Japanese Journal of Applied Physics
- Published
- 2025-09-16
- DOI
- https://doi.org/10.35848/1347-4065/ae0775
- Citations
- 1
- Primary Topic
- Semiconductor materials and devices
- Type
- article
- Field-Weighted Citation Impact
- 0.73