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Title: Surface barrier height for different Al compositions and barrier layer thicknesses in AlGaN/GaN heterostructure field effect transistors

Abstract

In this paper, we present a physics based analytical model for the calculation of surface barrier height for given values of barrier layer thicknesses and Al mole fractions. An explicit expression for the two dimensional electron gas density is also developed incorporating the change in polarization charges for different Al mole fractions.

Authors:
;  [1];  [2]
  1. Norwegian University of Science and Technology, Trondheim (Norway)
  2. Universitat Rovira i Virgili, Tarragona (Spain)
Publication Date:
OSTI Identifier:
22261872
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1566; Journal Issue: 1; Conference: ICPS 2012: 31. international conference on the physics of semiconductors, Zurich (Switzerland), 29 Jul - 3 Aug 2012; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; DENSITY; ELECTRON GAS; FIELD EFFECT TRANSISTORS; GALLIUM NITRIDES; POLARIZATION; THICKNESS

Citation Formats

Goyal, Nitin, E-mail: goyalnitin.iitr@gmail.com, Fjeldly, Tor A., and Iniguez, Benjamin. Surface barrier height for different Al compositions and barrier layer thicknesses in AlGaN/GaN heterostructure field effect transistors. United States: N. p., 2013. Web. doi:10.1063/1.4848451.
Goyal, Nitin, E-mail: goyalnitin.iitr@gmail.com, Fjeldly, Tor A., & Iniguez, Benjamin. Surface barrier height for different Al compositions and barrier layer thicknesses in AlGaN/GaN heterostructure field effect transistors. United States. doi:10.1063/1.4848451.
Goyal, Nitin, E-mail: goyalnitin.iitr@gmail.com, Fjeldly, Tor A., and Iniguez, Benjamin. 2013. "Surface barrier height for different Al compositions and barrier layer thicknesses in AlGaN/GaN heterostructure field effect transistors". United States. doi:10.1063/1.4848451.
@article{osti_22261872,
title = {Surface barrier height for different Al compositions and barrier layer thicknesses in AlGaN/GaN heterostructure field effect transistors},
author = {Goyal, Nitin, E-mail: goyalnitin.iitr@gmail.com and Fjeldly, Tor A. and Iniguez, Benjamin},
abstractNote = {In this paper, we present a physics based analytical model for the calculation of surface barrier height for given values of barrier layer thicknesses and Al mole fractions. An explicit expression for the two dimensional electron gas density is also developed incorporating the change in polarization charges for different Al mole fractions.},
doi = {10.1063/1.4848451},
journal = {AIP Conference Proceedings},
number = 1,
volume = 1566,
place = {United States},
year = 2013,
month =
}
  • A measurement methodology involving the synchronous switching of gate to source voltage and drain to source voltage (V{sub DS}) was proposed for determining the shift of threshold voltage after an AlGaN/GaN heterostructure transistor endures high V{sub DS} off-state stress. The measurement results indicated slow electron detrapping behavior. The trap level was determined as (E{sub C} – 0.6 eV). Simulation tool was used to analyze the measurement results. The simulation results were consistent with the experimental results; and a relationship between the buffer trap and threshold voltage shift over time was observed.
  • The dc characteristics of the AlGaN/GaN heterostructure field-effect transistors were examined at temperatures ranging from 25 to 260 deg. C under white light illumination. Drain current collapse measured was defined by the difference of drain current between light on and light off at V{sub gs}=1 V and V{sub ds}=5 V. The surface-passivated device showed no drain current collapse, but the unpassivated device showed severe drain current collapse at 25 deg. C. Drain current and drain current collapse with an increase in temperature reduced, which resulted from the reduction of the electron mobility or saturation velocity and the thermal activation ofmore » the trapped electrons, respectively. Eventually, drain current collapse disappeared completely above 250 deg. C. The behavior of the temperature-dependent drain current collapse showed that the surface states for trapping electrons were continuously distributed with the temperature not having specific energy states.« less
  • This is the report on trap states in enhancement-mode AlGaN/GaN/AlGaN double heterostructures high electron mobility transistors by fluorine plasma treatment with different GaN channel layer thicknesses. Compared with the thick GaN channel layer sample, the thin one has smaller 2DEG concentration, lower electron mobility, lower saturation current, and lower peak transconductance, but it has a higher threshold voltage of 1.2 V. Deep level transient spectroscopy measurements are used to obtain the accurate capture cross section of trap states. By frequency dependent capacitance and conductance measurements, the trap state density of (1.98–2.56) × 10{sup 12 }cm{sup −2} eV{sup −1} is located at E{sub T} inmore » a range of (0.37–0.44) eV in the thin sample, while the trap state density of (2.3–2.92) × 10{sup 12 }cm{sup −2} eV{sup −1} is located at E{sub T} in a range of (0.33–0.38) eV in the thick one. It indicates that the trap states in the thin sample are deeper than those in the thick one.« less
  • The theoretical model of the polarization Coulomb field scattering (PCF) caused by the polarization charge density variation at the AlGaN/AlN interface in strained AlGaN/AlN/GaN heterostructure field-effect transistors has been developed. And the theoretical values for the electron drift mobility, which were calculated using the Matthiessen's rule that includes PCF, piezoelectric scattering, polar optical-phonon scattering, and interface roughness scattering, are in good agreement with our experimental values. Therefore, the theoretical model for PCF has been confirmed.