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Title: Evaluation of AlGaN/GaN high electron mobility transistors grown on ZrTi buffer layers with sapphire substrates

Here, AlGaN/GaN high electron mobility transistors (HEMTs) have been grown on sapphire substrates, using ZrTi buffer layers to provide in-plane lattice-matching to hexagonal GaN. X-ray diffraction (XRD) as well as cross-section transmission electron microscopy (TEM) were used to assess the quality of the HEMT structure. The XRD 2θ scans showed full-width-at-half-maximum values of 0.16°, 0.07°, and 0.08° for ZrTi alloy, GaN buffer layer, and the entire HEMT structure, respectively. TEM studies of the GaN buffer layer and the AlN/ZrTi/AlN stack showed the importance of growing thin AlN buffer layers on the ZrTi layer prior to growth of the GaN buffer layer. The density of threading dislocations in the GaN channel layer of the HEMT structure was estimated to be in the 10 8 cm –2 range. The HEMT device exhibited a saturation drain current density of 820 mA/mm, and the channel of the fabricated HEMTs could be well modulated. A cutoff frequency (f T) of 8.9 GHz and a maximum frequency of oscillation (f max) of 17.3 GHz were achieved for HEMTs with gate dimensions of 1 × 200 μm.
Authors:
 [1] ;  [1] ;  [1] ;  [1] ;  [2] ;  [2] ;  [2] ;  [3] ;  [3] ;  [4]
  1. Univ. of Florida, Gainesville, FL (United States)
  2. Triva Corp., Oakland, CA (United States)
  3. Arizona State Univ., Tempe, AZ (United States)
  4. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Publication Date:
Grant/Contract Number:
AC05-00OR22725
Type:
Accepted Manuscript
Journal Name:
Journal of Vacuum Science and Technology. B, Nanotechnology and Microelectronics
Additional Journal Information:
Journal Volume: 34; Journal Issue: 5; Journal ID: ISSN 2166-2746
Publisher:
American Vacuum Society/AIP
Research Org:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences (CNMS)
Sponsoring Org:
USDOE Office of Science (SC)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; MODETs; III-V semiconductors; buffer layers; sapphire; transmission electron microscopy
OSTI Identifier:
1327654

Ren, Fan, Pearton, Stephen J., Ahn, Shihyun, Lin, Yi -Hsuan, Machuca, Francisco, Weiss, Robert, Welsh, Alex, McCartney, Martha R., Smith, David J., and Kravchenko, Ivan I.. Evaluation of AlGaN/GaN high electron mobility transistors grown on ZrTi buffer layers with sapphire substrates. United States: N. p., Web. doi:10.1116/1.4963064.
Ren, Fan, Pearton, Stephen J., Ahn, Shihyun, Lin, Yi -Hsuan, Machuca, Francisco, Weiss, Robert, Welsh, Alex, McCartney, Martha R., Smith, David J., & Kravchenko, Ivan I.. Evaluation of AlGaN/GaN high electron mobility transistors grown on ZrTi buffer layers with sapphire substrates. United States. doi:10.1116/1.4963064.
Ren, Fan, Pearton, Stephen J., Ahn, Shihyun, Lin, Yi -Hsuan, Machuca, Francisco, Weiss, Robert, Welsh, Alex, McCartney, Martha R., Smith, David J., and Kravchenko, Ivan I.. 2016. "Evaluation of AlGaN/GaN high electron mobility transistors grown on ZrTi buffer layers with sapphire substrates". United States. doi:10.1116/1.4963064. https://www.osti.gov/servlets/purl/1327654.
@article{osti_1327654,
title = {Evaluation of AlGaN/GaN high electron mobility transistors grown on ZrTi buffer layers with sapphire substrates},
author = {Ren, Fan and Pearton, Stephen J. and Ahn, Shihyun and Lin, Yi -Hsuan and Machuca, Francisco and Weiss, Robert and Welsh, Alex and McCartney, Martha R. and Smith, David J. and Kravchenko, Ivan I.},
abstractNote = {Here, AlGaN/GaN high electron mobility transistors (HEMTs) have been grown on sapphire substrates, using ZrTi buffer layers to provide in-plane lattice-matching to hexagonal GaN. X-ray diffraction (XRD) as well as cross-section transmission electron microscopy (TEM) were used to assess the quality of the HEMT structure. The XRD 2θ scans showed full-width-at-half-maximum values of 0.16°, 0.07°, and 0.08° for ZrTi alloy, GaN buffer layer, and the entire HEMT structure, respectively. TEM studies of the GaN buffer layer and the AlN/ZrTi/AlN stack showed the importance of growing thin AlN buffer layers on the ZrTi layer prior to growth of the GaN buffer layer. The density of threading dislocations in the GaN channel layer of the HEMT structure was estimated to be in the 108 cm–2 range. The HEMT device exhibited a saturation drain current density of 820 mA/mm, and the channel of the fabricated HEMTs could be well modulated. A cutoff frequency (fT) of 8.9 GHz and a maximum frequency of oscillation (fmax) of 17.3 GHz were achieved for HEMTs with gate dimensions of 1 × 200 μm.},
doi = {10.1116/1.4963064},
journal = {Journal of Vacuum Science and Technology. B, Nanotechnology and Microelectronics},
number = 5,
volume = 34,
place = {United States},
year = {2016},
month = {9}
}