Polarization modulation effect of BeO on AlGaN/GaN high-electron-mobility transistors

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 (...

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Veröffentlicht in:Applied physics letters 2019-09, Vol.115 (10)
Hauptverfasser: Wang, Weijie, Lee, Seung Min, Pouladi, Sara, Chen, Jie, Shervin, Shahab, Yoon, Seonno, Yum, Jung Hwan, Larsen, Eric S., Bielawski, Christopher W., Chatterjee, Bikramjit, Choi, Sukwon, Oh, Jungwoo, Ryou, Jae-Hyun
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Sprache:eng
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Zusammenfassung: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.
ISSN:0003-6951
1077-3118
DOI:10.1063/1.5108832