| AVS 65th International Symposium & Exhibition | |
| Electronic Materials and Photonics Division | Thursday Sessions |
| Session EM-ThP |
| Session: | Electronic Materials and Photonics Division Poster Session |
| Presenter: | Min Khanal, Auburn University |
| Authors: | M.P. Khanal, Auburn University S. Uprety, Auburn University K. Yapabandara, Auburn University V. Mirkhani, Auburn University S. Wang, Auburn University B. Schoeneck, Auburn University T. Isaacs-Smith, Auburn University A. Ahyi, Auburn University M.J. Bozack, Auburn University M. Park, Auburn University |
| Correspondent: | Click to Email |
The electronics that are used in spacecraft are subject to space radiation hazards. The space radiation environment includes trapped electrons and protons of the Van Allen radiation belts, and non-trapped transient solar and galactic cosmic rays and solar flare particles. The protons with the cut-off energy of 100 keV are present above the upstream of the Earth’s bow shock. Since gallium nitride and its alloys are proven to be relatively radiation tolerant, these materials are considered as promising candidates for space electronic applications. Therefore, it is consequential to study the effect of 100 keV protons on the AlGaN/GaN HEMTs if the devices are to be used for space applications. In this research, the effect of 100 keV protons with the fluences 1×1010, 1×1012, and 1×1014 cm-2 on materials/device characteristics of AlGaN/GaN HEMTs constructed on Si wafers were studied by means of optical and electrical characterization. The electrical characteristics of the devices were analyzed by using conventional transistor I-V and C-V measurements in order to relate the material’s fundamental properties to the device performance. The slight degradation on the electrical characteristics and the shift in the threshold voltage was observed in the irradiated samples. The crystal quality of the epilayer was examined via micro-Raman spectroscopy and no substantial degradation in the crystal quality was observed.The possible introduction and/or the alternation of the defects were probed using the photoluminescence (PL) spectroscopy and spectroscopic photocurrent-voltage techniques. The surface morphology of the samples was studied by atomic force microscopy (AFM) and scanning electron microscopy (SEM), and a slight increase in the surface roughness was observed. The surface analysis was performed using X-ray photoelectron spectroscopy, and the surface elemental composition was not altered after irradiation. It is concluded that the crystal quality of the AlGaN/GaN HEMT layers and the electrical characteristics of the AlGaN/GaN HEMTs were not severely degraded in spite of the exposure to a high fluence of protons with the energy 100 keV.