| Autor: |
Muhammad Asad, Marlene Bonmann, Xinxin Yang, Andrei Vorobiev, Kjell Jeppson, Luca Banszerus, Martin Otto, Christoph Stampfer, Daniel Neumaier, Jan Stake |
| Jazyk: |
angličtina |
| Rok vydání: |
2020 |
| Předmět: |
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| Zdroj: |
IEEE Journal of the Electron Devices Society, Vol 8, Pp 457-464 (2020) |
| Druh dokumentu: |
article |
| ISSN: |
2168-6734 |
| DOI: |
10.1109/JEDS.2020.2988630 |
| Popis: |
This paper addresses the high-frequency performance limitations of graphene field-effect transistors (GFETs) caused by material imperfections. To understand these limitations, we performed a comprehensive study of the relationship between the quality of graphene and surrounding materials and the high-frequency performance of GFETs fabricated on a silicon chip. We measured the transit frequency (fT) and the maximum frequency of oscillation (fmax) for a set of GFETs across the chip, and as a measure of the material quality, we chose low-field carrier mobility. The low-field mobility varied across the chip from 600 cm2/Vs to 2000 cm2/Vs, while the fT and fmax frequencies varied from 20 GHz to 37 GHz. The relationship between these frequencies and the low-field mobility was observed experimentally and explained using a methodology based on a small-signal equivalent circuit model with parameters extracted from the drain resistance model and the charge-carrier velocity saturation model. Sensitivity analysis clarified the effects of equivalent-circuit parameters on the fT and fmax frequencies. To improve the GFET high-frequency performance, the transconductance was the most critical parameter, which could be improved by increasing the charge-carrier saturation velocity by selecting adjacent dielectric materials with optical phonon energies higher than that of SiO2. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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