High-electron mobility transistors (HEMTs) are important for high frequency applications, and they now operate in the range of several hundred GHz for the cut-off frequency, fT and even higher for the maximum frequency of oscillation, fmax. To study the question of how much higher these frequencies can be pushed, we have used a full-band, cellular Monte Carlo transport program to study scaled pseudomorphic HEMTs and their response at high frequency. Building on a previous study on fT, we have obtained the unilateral power gain for gate lengths ranging from 10 to 50 nm, extracted the corresponding fmax's and extrapolated the results to determine an ultimate frequency limit for the 300 nm long device shown here.. We find that fmax can exceed 4 THz, ~25% higher than the limit for fT that was previously obtained. We also examine the effect of varying the gate to channel spacing has on the operation of these devices.

Original languageEnglish (US)
Pages (from-to)2502-2505
Number of pages4
JournalPhysica Status Solidi (C) Current Topics in Solid State Physics
Issue number10
StatePublished - Oct 2010


  • Electronic transport
  • Heterojunctions
  • III-V semiconductors
  • Semiconductor devices

ASJC Scopus subject areas

  • Condensed Matter Physics


Dive into the research topics of 'Optimizing performance to achieve multi-terahertz operating frequencies in pseudomorphic HEMTs'. Together they form a unique fingerprint.

Cite this