Abstract
AlGaN/GaN high electron mobility transistors (HEMTs) were demonstrated for structures grown on ZrTi metallic alloy buffer layers, which provided lattice matching of the in-plane lattice parameter (“a-parameter”) to hexagonal GaN. The quality of the GaN buffer layer and HEMT structure were confirmed with X-ray 2θ and rocking scans as well as cross-section transmission electron microscopy (TEM) images. The X-ray 2θ scans showed full widths at half maximum (FWHM) of 0.06◦, 0.05◦ and 0.08◦ for ZrTi alloy, GaN buffer layer, and the entire HEMT structure, respectively. TEM of the lower section of the HEMT structure containing the GaN buffer layer and the AlN/ZrTi/AlN stack on the Si substrate showed that it was important to grow AlN on the top of ZrTi prior to growing the GaN buffer layer. The estimated threading dislocation (TD) density in the GaN channel layer of the HEMT structure was in the 108 cm−2 range.
Original language | English |
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Pages (from-to) | S3078-S3080 |
Journal | ECS Journal of Solid State Science and Technology |
Volume | 6 |
Issue number | 11 |
DOIs | |
State | Published - 2017 |
Funding
The work performed at UF was supported by an AFOSR contract No FA8650-15-M-1912 monitored by Rafael Pappaterra. A portion of this research was conducted at the Center for Nanophase Materials Sciences, which is a DOE Office of Science User Facility. The electron microscopy studied at ASU were supported under contract to Wyle Laboratories as part of Reliability Information analysis Center Contract HC1047-05-D4005 under the Air Force Research Laboratory Sensors Directorate Technical Task 261 monitored by Christopher Bozada.