By Topic

Carrier transport related analysis of high-power AlGaN/GaN HEMT structures

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)
Shah, P.B. ; U.S. Army Res. Lab., Adelphi, MD, USA ; Smith, Doran D. ; Griffin, T.E. ; Jones, K.A.
more authors

Shubnikov-de Haas (SdH) oscillation and Hall measurement results were compared with HEMT DC and RF characteristics for two different MOCVD grown AlGaN-GaN HEMT structures on semiinsulating 4H-SiC substrates. A HEMT with a 40-nm, highly doped AlGaN cap layer exhibited an electron mobility of 1500 cm2/V/s and a sheet concentration of 9×1012 cm at 300 K (7900 cm2/V/s and 8×1012 cm-2 at 80 K), but showed a high threshold voltage and high DC output conductance. A 27-nm AlGaN cap with a thinner, lightly doped donor layer yielded similar Hall values, but lower threshold voltage and output conductance and demonstrated a high CW power density of 6.9 W/mm at 10 GHz. The 2DEG of this improved structure had a sheet concentration of nSdH=7.8×1012 cm-2 and a high quantum scattering lifetime of τq=1.5×10-13 s at 4.2 K compared to nSdH=8.24×1012 cm-2 and τq=1.72×10-13 s for the thick AlGaN cap layer structure, Despite the excellent characteristics of the films, the SdH oscillations still indicate a slight parallel conduction and a weak localization of electrons. These results indicate that good channel quality and high sheet carrier density are not the only HEMT attributes required for good transistor performance

Published in:

Electron Devices, IEEE Transactions on  (Volume:47 ,  Issue: 2 )