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Contribution of alloy clustering to limiting the two-dimensional electron gas mobility in AlGaN/GaN and InAlN/GaN heterostructures: Theory and experiment

Journal Article · · Journal of Applied Physics
DOI:https://doi.org/10.1063/1.4896967· OSTI ID:22305752
;  [1];  [2]; ; ;  [3]
  1. Electrical and Computer Engineering Department, University of California, Santa Barbara, California 93106 (United States)
  2. Geballe Laboratory for Advanced Materials, Stanford University, Stanford, California 94305 (United States)
  3. Materials Department, University of California, Santa Barbara, California 93106 (United States)

The influence of alloy clustering on fluctuations in the ground state energy of the two-dimensional electron gas (2DEG) in AlGaN/GaN and InAlN/GaN heterostructures is studied. We show that because of these fluctuations, alloy clustering degrades the mobility even when the 2DEG wavefunction does not penetrate the alloy barrier unlike alloy disorder scattering. A comparison between the results obtained for AlGaN/GaN and InAlN/GaN heterostructures shows that alloy clustering limits the 2DEG mobility to a greater degree in InAlN/GaN heterostructures. Our study also reveals that the inclusion of an AlN interlayer increases the limiting mobility from alloy clustering. Moreover, Atom probe tomography is used to demonstrate the random nature of the fluctuations in the alloy composition.

OSTI ID:
22305752
Journal Information:
Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 13 Vol. 116; ISSN JAPIAU; ISSN 0021-8979
Country of Publication:
United States
Language:
English

Cited By (4)

Analysis of Leakage Current Mechanism for Ni/Au Schottky Contact on InAlGaN/GaN HEMT journal April 2018
Achieving high electron mobility in AlInGaN/GaN heterostructures: The correlation between thermodynamic stability and electron transport properties journal June 2019
Enhanced mobility in vertically scaled N-polar high-electron-mobility transistors using GaN/InGaN composite channels journal February 2018
Schottky barrier height of Ni to β -(Al x Ga 1−x ) 2 O 3 with different compositions grown by plasma-assisted molecular beam epitaxy journal January 2017