| Autor: |
Li, Jiye, Guan, Yuhang, Li, Jinxiong, Zhang, Yuqing, Zhang, Yuhan, Chan, ManSun, Wang, Xinwei, Lu, Lei, Zhang, Shengdong |
| Předmět: |
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| Zdroj: |
Nanotechnology; 6/25/2023, Vol. 34 Issue 26, p1-8, 8p |
| Abstrakt: |
To strengthen the downscaling potential of top-gate amorphous oxide semiconductor (AOS) thin-film transistors (TFTs), the ultra-thin gate insulator (GI) was comparatively implemented using the atomic-layer-deposited (ALD) AlO x and HfO x. Both kinds of high- k GIs exhibit good insulating properties even with the physical thickness thinning to 4 nm. Compared to the amorphous indium-gallium-zinc oxide (a-IGZO) TFTs with 4 nm AlO x GI, the 4 nm HfO x enables a larger GI capacitance, while the HfO x -gated TFT suffers higher gate leakage current and poorer subthreshold slope, respectively originating from the inherently small band offset and the highly defective interface between a-IGZO and HfO x. Such imperfect a-IGZO/HfO x interface further causes noticeable positive bias stress instability. Both ALD AlO x and HfO x were found to react with the underneath a-IGZO channel to generate the interface defects, such as metal interstitials and oxygen vacancies, while the ALD process of HfO x gives rise to a more severe reduction of a-IGZO. Moreover, when such a defective interface is covered by the top gate, it cannot be readily restored using the conventional oxidizing post-treatments and thus desires the reduction-resistant pre-treatments of AOSs. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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