Polarization modulation effect of BeO on AlGaN/GaN high-electron-mobility transistors
| Autor: | Christopher W. Bielawski, Eric S. Larsen, Jung Hwan Yum, Seung Min Lee, Sukwon Choi, Jae-Hyun Ryou, Jie Chen, Seonno Yoon, Sara Pouladi, Bikramjit Chatterjee, Jungwoo Oh, Weijie Wang, Shahab Shervin |
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| Rok vydání: | 2019 |
| Předmět: |
010302 applied physics
Materials science Physics and Astronomy (miscellaneous) business.industry Transistor Heterojunction 02 engineering and technology High-electron-mobility transistor 021001 nanoscience & nanotechnology Polarization (waves) 01 natural sciences law.invention Barrier layer law 0103 physical sciences Optoelectronics Thin film 0210 nano-technology business Fermi gas Quantum well |
| Zdroj: | Applied Physics Letters. 115:103502 |
| ISSN: | 1077-3118 0003-6951 |
| DOI: | 10.1063/1.5108832 |
| Popis: | We investigate the polarization modulation effect of a single-crystalline BeO layer on AlGaN/GaN high-electron-mobility transistors (HEMTs). The BeO layer with macroscopic polarization on top of the AlGaN barrier layer increases the 2-dimensional electron gas density in the triangular quantum well (QW) at the interface of the AlGaN/GaN heterostructure. Electronic band bending of BeO and a deeper triangular QW observed from the simulated conduction band profile indicate that the BeO layer can modify the polarization field at the AlGaN/GaN interface. A ∼20-nm-thick single-crystalline BeO thin film is grown on AlGaN/GaN HEMTs by atomic-layer deposition. Room-temperature and variable-temperature Hall-effect measurements confirm that the HEMT with BeO forms a channel with a 14% increase of the sheet carrier concentration as compared with a conventional HEMT. An improved output performance is also observed in the I-V characteristics which confirms the polarization modulation effect of the BeO layer.We investigate the polarization modulation effect of a single-crystalline BeO layer on AlGaN/GaN high-electron-mobility transistors (HEMTs). The BeO layer with macroscopic polarization on top of the AlGaN barrier layer increases the 2-dimensional electron gas density in the triangular quantum well (QW) at the interface of the AlGaN/GaN heterostructure. Electronic band bending of BeO and a deeper triangular QW observed from the simulated conduction band profile indicate that the BeO layer can modify the polarization field at the AlGaN/GaN interface. A ∼20-nm-thick single-crystalline BeO thin film is grown on AlGaN/GaN HEMTs by atomic-layer deposition. Room-temperature and variable-temperature Hall-effect measurements confirm that the HEMT with BeO forms a channel with a 14% increase of the sheet carrier concentration as compared with a conventional HEMT. An improved output performance is also observed in the I-V characteristics which confirms the polarization modulation effect of the BeO layer. |
| Databáze: | OpenAIRE |
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