Evaluation of AlGaN/GaN high electron mobility transistors grown on ZrTi buffer layers with sapphire substrates
| Autor: | Francisco Machuca, Ivan I. Kravchenko, Fan Ren, Stephen J. Pearton, Yi Hsuan Lin, David J. Smith, Alex Welsh, Robert Weiss, Martha R. McCartney, Shihyun Ahn |
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| Rok vydání: | 2016 |
| Předmět: |
010302 applied physics
Materials science business.industry Process Chemistry and Technology Wide-bandgap semiconductor 02 engineering and technology High-electron-mobility transistor 021001 nanoscience & nanotechnology 01 natural sciences Cutoff frequency Surfaces Coatings and Films Electronic Optical and Magnetic Materials Transmission electron microscopy 0103 physical sciences X-ray crystallography Materials Chemistry Sapphire Optoelectronics Electrical and Electronic Engineering 0210 nano-technology business Instrumentation Current density Saturation (magnetic) |
| Zdroj: | Journal of Vacuum Science & Technology B, Nanotechnology and Microelectronics: Materials, Processing, Measurement, and Phenomena. 34:051208 |
| ISSN: | 2166-2754 2166-2746 |
| DOI: | 10.1116/1.4963064 |
| Popis: | 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 w... |
| Databáze: | OpenAIRE |
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