Channel Thickness Impact on the Small- and Large-Signal RF Performance of GaN HEMTs on Si with a cGaN Back-Barrier

Rana ElKashlan, Ahmad Khaled, Raul Rodriguez, Sachin Yadav, Uthayasankaran Peralagu, AliReza Alian, Nadine Collaert, Piet Wambacq, Bertrand Parvais

Research output: Chapter in Book/Report/Conference proceedingConference paperResearch

2 Citations (Scopus)


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 ~33%, ~20% decline in fT,fMAX respectively, for 70nm devices. While the large-signal metrics, PSAT and PAE, at 6GHz drop by ~46% and ~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 ~20%.
Original languageEnglish
Title of host publication2022 IEEE/MTT-S International Microwave Symposium - IMS 2022
Place of PublicationDenver, CO, USA
PublisherInstitute of Electrical and Electronics Engineers Inc.
Number of pages4
ISBN (Electronic)978-1-6654-9613-1
ISBN (Print)978-1-6654-9614-8
Publication statusPublished - 29 Aug 2022
EventMicrowave, MTT-S International Symposium: 2022 IEEE/MTT-S International Microwave Symposium - Denver, CO, Denver, United States
Duration: 19 Jun 202224 Jun 2022


ConferenceMicrowave, MTT-S International Symposium
Abbreviated titleIMS 2022
Country/TerritoryUnited States


  • Gallium Nitride
  • HEMTs
  • power amplifiers (PAs)
  • radio frequency


Dive into the research topics of 'Channel Thickness Impact on the Small- and Large-Signal RF Performance of GaN HEMTs on Si with a cGaN Back-Barrier'. Together they form a unique fingerprint.

Cite this