Self-Aligned Amorphous Indium-Tin-Zinc-Oxide Thin Film Transistors on Polyimide Foil
| Main Authors: | Rishabh Upadhyay, Soeren Steudel, Mai-Phi Hung, Akhilesh Kumar Mandal, Francky Catthoor, Manoj Nag |
|---|---|
| Format: | Article Journal |
| Terbitan: |
, 2018
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| Online Access: |
https://zenodo.org/record/3364516 |
Daftar Isi:
- In this work, we report on high-performance coplanar self-aligned (SA) amorphous-Indium-Tin-Zinc-Oxide (a-ITZO) thin-film transistors (TFTs) on flexible polyimide substrate. The a-ITZO films are first optimized with respect to the oxygen ratio, thickness and final anneal conditions with common-gate TFTs structure on Si/SiO2 substrate. Optimized TFTs show mobility (μlin) between 20.0–25.0 cm2/(V.s). Material characterization revealed some degree of order compared to a truly amorphous film like a-IGZO but no grain boundaries or crystalline domains were observed. The a-ITZO films were integrated in coplanar SA TFT architecture on polyimide using hydrogen rich plasma (SiH4 based chemistry) as dopant for the source/drain (S/D) regions resulting in field-effect mobility (μFE) of 27.0 cm2/ (V.s), sub-threshold slope (SS−1) of 0.40 V/decade and ION /IOFF ratio of >108. The threshold voltage shifts of the TFTs under both positive and negative gate bias stress of 1MV/cm for 104 seconds were less than 1.5 V. We have also investigated the applicability of the SA a-ITZO TFTs in logic circuitry such as 19-stage ring-oscillators (ROs).