By Topic

Comprehensive analysis of small-signal parameters of fully strained and partially relaxed high Al-content lattice mismatched AlmGa1-mN/GaN HEMTs

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$31 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

5 Author(s)
Rashmi ; Dept. of Electron. Sci., Univ. of Delhi, New Delhi, India ; Kranti, A. ; Haldar, S. ; Gupta, M.
more authors

Proposes an accurate model to investigate the small-signal microwave parameters of fully strained (FS) and partially relaxed (PR) AlmGa1-mN/GaN high electron-mobility transistors (HEMTs). It is observed that elastic strain relaxation of the AlmGa1-mN layer imposes an upper limit on the maximum two-dimensional electron-gas sheet charge density and is, thus, extremely critical in determining the microwave performance of high Al-content AlmGa1-mN/GaN HEMTs. The model incorporates the effects of strain relaxation of the barrier layer, field-dependent mobility, parasitic source/drain resistance, and velocity saturation to evaluate drain current, transconductance, drain conductance, cutoff frequency, and transit time of FS and PR AlmGa1-mN/GaN HEMTs with different Al mole fractions. The proposed model predicts a high drain current of 5.94 A/mm for a PR 0.3-μm Al0.4Ga0.6N/GaN HEMT, which is in close proximity with previously published simulated results. A peak transconductance of 154 mS/mm is also estimated for a 1-μm gate-length device with aluminum concentration of 15% (FS), which is in close agreement with previously published measured data. A high cutoff frequency of 21.09 GHz was predicted for a 0.6-μm device with an Al mole fraction of 0.5 (PR), thus showing the potential of AlGaN/GaN HEMTs for microwave applications.

Published in:

Microwave Theory and Techniques, IEEE Transactions on  (Volume:51 ,  Issue: 2 )