دورية أكاديمية

Variability and high temperature reliability of graphene field-effect transistors with thin epitaxial CaF2 insulators

التفاصيل البيبلوغرافية
العنوان: Variability and high temperature reliability of graphene field-effect transistors with thin epitaxial CaF2 insulators
المؤلفون: Yu. Yu. Illarionov, T. Knobloch, B. Uzlu, A. G. Banshchikov, I. A. Ivanov, V. Sverdlov, M. Otto, S. L. Stoll, M. I. Vexler, M. Waltl, Z. Wang, B. Manna, D. Neumaier, M. C. Lemme, N. S. Sokolov, T. Grasser
المصدر: npj 2D Materials and Applications, Vol 8, Iss 1, Pp 1-10 (2024)
بيانات النشر: Nature Portfolio, 2024.
سنة النشر: 2024
المجموعة: LCC:Materials of engineering and construction. Mechanics of materials
LCC:Chemistry
مصطلحات موضوعية: Materials of engineering and construction. Mechanics of materials, TA401-492, Chemistry, QD1-999
الوصف: Abstract Graphene is a promising material for applications as a channel in graphene field-effect transistors (GFETs) which may be used as a building block for optoelectronics, high-frequency devices and sensors. However, these devices require gate insulators which ideally should form atomically flat interfaces with graphene and at the same time contain small densities of traps to maintain high device stability. Previously used amorphous oxides, such as SiO2 and Al2O3, however, typically suffer from oxide dangling bonds at the interface, high surface roughness and numerous border oxide traps. In order to address these challenges, here we use 2 nm thick epitaxial CaF2 as a gate insulator in GFETs. By analyzing device-to-device variability for about 200 devices fabricated in two batches, we find that tens of them show similar gate transfer characteristics. Our statistical analysis of the hysteresis up to 175oC has revealed that while an ambient-sensitive counterclockwise hysteresis can be present in some devices, the dominant mechanism is thermally activated charge trapping by border defects in CaF2 which results in the conventional clockwise hysteresis. We demonstrate that both the hysteresis and bias-temperature instabilities in our GFETs with CaF2 are comparable to similar devices with SiO2 and Al2O3. In particular, we achieve a small hysteresis below 0.01 V for equivalent oxide thickness (EOT) of about 1 nm at the electric fields up to 15 MV cm−1 and sweep times in the kilosecond range. Thus, our results demonstrate that crystalline CaF2 is a promising insulator for highly-stable GFETs.
نوع الوثيقة: article
وصف الملف: electronic resource
اللغة: English
تدمد: 2397-7132
Relation: https://doaj.org/toc/2397-7132
DOI: 10.1038/s41699-024-00461-0
URL الوصول: https://doaj.org/article/3aabc0628c8b44959f15e605e0a876d5
رقم الأكسشن: edsdoj.3aabc0628c8b44959f15e605e0a876d5
قاعدة البيانات: Directory of Open Access Journals
الوصف
تدمد:23977132
DOI:10.1038/s41699-024-00461-0