Enhanced Mobility in InAlN/AlN/GaN HEMTs Using a GaN Interlayer
Journal article, 2019

© 1963-2012 IEEE. An enhancement of the electron mobility ( \mu ) in InAlN/AlN/GaN heterostructures is demonstrated by the incorporation of a thin GaN interlayer (IL) between the InAlN and AlN. The introduction of a GaN IL increases \mu at room temperature (RT) from 1600 to 1930 cm2/Vs. The effect is further enhanced at cryogenic temperature (5 K), where the GaN IL sample exhibits a \mu of 16000 cm2/Vs, compared to 6900 cm2/Vs without IL. The results indicate the reduction of one or more scattering mechanisms normally present in InAlN/AlN/GaN heterostructures. We propose that the improvement in \mu is either due to the suppression of fluctuations in the quantum well subband energies or to reduced Coulomb scattering, both related to compositional variations in the InAlN. HEMTs fabricated on the GaN IL sample demonstrate larger improvement in dc-and high-frequency performance at 5 K; {f}-{\text {max}} increases by 25 GHz to 153 GHz, compared to an increase of 6 GHz to 133 GHz without IL. The difference in improvement was associated mainly with the drop in the access resistances.


interlayer (IL)




Cryogenic temperature


Anna Malmros


Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics

J. T. Chen

Linköping University

Hans Hjelmgren

Linköping University

Jun Lu

Linköping University

L. Hultman

Linköping University

O. Kordina

Linköping University

E. O. Sveinbjornsson

University of Iceland

Herbert Zirath

Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics

Niklas Rorsman

Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics

IEEE Transactions on Electron Devices

0018-9383 (ISSN) 15579646 (eISSN)

Vol. 66 7 2910-2915 8731885

Subject Categories

Materials Chemistry

Other Physics Topics

Condensed Matter Physics



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7/2/2019 2