We examine the influence of scaling the GaN channel thickness from 100nm to 35nm on the RF performance for GaN HEMTs on Si with a cGaN back-barrier with gate lengths ranging from 70nm to 190nm. Thinner GaN channels notably improve the short channel effects. However, there is a degradation in the on-state performance associated with an increase in dispersion. These trade-offs translate to a \textasciitilde{}33\%, \textasciitilde{}20\% decline in fT,fMAX respectively, for 70nm devices. While the large-signal metrics, PSAT and PAE, at 6GHz drop by \textasciitilde{}46\% and \textasciitilde{}18\%, respectively. We also consider the lateral downscaling of the gate-to-drain and gate-to-source spacings, which proves beneficial in boosting PSAT, up to 3.4W/mm, by increasing the extrinsic transconductance by \textasciitilde{}20\%.
ElKashlan, R, Khaled, A, Rodriguez, R, Yadav, S, Peralagu, U, Alian, A, Collaert, N, Wambacq, P & Parvais, B 2022, Channel Thickness Impact on the Small- and Large-Signal RF Performance of GaN HEMTs on Si with a cGaN Back-Barrier. in 2022 IEEE/MTT-S International Microwave Symposium - IMS 2022. IEEE MTT-S International Microwave Symposium digest, Institute of Electrical and Electronics Engineers Inc., Denver, CO, USA, pp. 910-913, Microwave, MTT-S International Symposium, Denver, Colorado, United States, 19/06/22. https://doi.org/10.1109/IMS37962.2022.9865258
ElKashlan, R., Khaled, A., Rodriguez, R., Yadav, S., Peralagu, U., Alian, A., Collaert, N., Wambacq, P., & Parvais, B. (2022). Channel Thickness Impact on the Small- and Large-Signal RF Performance of GaN HEMTs on Si with a cGaN Back-Barrier. In 2022 IEEE/MTT-S International Microwave Symposium - IMS 2022 (pp. 910-913). (IEEE MTT-S International Microwave Symposium digest). Institute of Electrical and Electronics Engineers Inc.. https://doi.org/10.1109/IMS37962.2022.9865258
@inproceedings{f9573dcfd2ec4c8d86b0daf139f10fb1,
title = "Channel Thickness Impact on the Small- and Large-Signal RF Performance of GaN HEMTs on Si with a cGaN Back-Barrier",
abstract = "We examine the influence of scaling the GaN channel thickness from 100nm to 35nm on the RF performance for GaN HEMTs on Si with a cGaN back-barrier with gate lengths ranging from 70nm to 190nm. Thinner GaN channels notably improve the short channel effects. However, there is a degradation in the on-state performance associated with an increase in dispersion. These trade-offs translate to a \textasciitilde{}33\%, \textasciitilde{}20\% decline in fT,fMAX respectively, for 70nm devices. While the large-signal metrics, PSAT and PAE, at 6GHz drop by \textasciitilde{}46\% and \textasciitilde{}18\%, respectively. We also consider the lateral downscaling of the gate-to-drain and gate-to-source spacings, which proves beneficial in boosting PSAT, up to 3.4W/mm, by increasing the extrinsic transconductance by \textasciitilde{}20\%.",
keywords = "Gallium Nitride, HEMTs, power amplifiers (PAs), radio frequency",
author = "Rana ElKashlan and Ahmad Khaled and Raul Rodriguez and Sachin Yadav and Uthayasankaran Peralagu and AliReza Alian and Nadine Collaert and Piet Wambacq and Bertrand Parvais",
year = "2022",
month = aug,
day = "29",
doi = "10.1109/IMS37962.2022.9865258",
language = "English",
isbn = "978-1-6654-9614-8",
series = "IEEE MTT-S International Microwave Symposium digest",
publisher = "Institute of Electrical and Electronics Engineers Inc.",
pages = "910--913",
booktitle = "2022 IEEE/MTT-S International Microwave Symposium - IMS 2022",
address = "United States",
note = "Microwave, MTT-S International Symposium : 2022 IEEE/MTT-S International Microwave Symposium, IMS 2022 ; Conference date: 19-06-2022 Through 24-06-2022",
}