High-frequency, high-power performance of AlGaN-channel high-electron-mobility transistors: an RF simulation study

• Published in: Japanese Journal of Applied Physics 2019-06, Vol.58 (SC), p.SCCD04
• Main Authors: Reza, Shahed, Klein, Brianna A., Baca, Albert. G., Armstrong, Andrew M., Allerman, Andrew A., Douglas, Erica. A., Kaplar, Robert J.
• Format: Article
• Language: English
• Subjects: Aluminum gallium nitrides; Carrier density; Computer simulation; Electric fields; Electronic devices; Electrons; ENGINEERING; High electron mobility transistors; Power efficiency; Semiconductor devices; Third order intercept point; Transistors
• ISSN: 0021-4922; 1347-4065
• DOI: 10.7567/1347-4065/ab07a5

The emerging Al-rich AlGaN-channel AlxGa1−xN/AlyGa1−yN high-electron-mobility transistors (HEMTs) with 0.7 ≤ y < x ≤ 1.0 have the potential to greatly exceed the power handling capabilities of today's GaN HEMTs, possibly by five times. This projection is based on the expected 4× enhancement of the critical electric field, the 2× enhancement of sheet carrier density, and the parity of the electron saturation velocity for Al-rich AlGaN-channel HEMTs relative to GaN-channel HEMTs. In this paper, the expected increased RF power density in Al-rich AlGaN-channel HEMTs is calculated by theoretical analysis and computer simulations, based on existing data on long-channel AlGaN devices. It is shown that a saturated power density of 18 W mm−1, a power-added efficiency of 55% and an output third-order intercept point over 40 dB can be achieved for this technology. The method for large-signal RF performance estimation presented in this paper is generic and can be applied to other novel high-power device technologies at the early stages of development.