Millimeter-Wave Donor-Acceptor-Doped DpHEMT

• Published in: IEEE transactions on electron devices 2021-01, Vol.68 (1), p.53-56
• Main Authors: Pashkovskii, Andrey B., Bogdanov, Sergey A., Bakarov, Askhat K., Grigorenko, Alexandr B., Zhuravlev, K. S., Lapin, Vladimir G., Lukashin, Vladimir M., Rogachev, Ilya A., Tereshkin, Evgeniy V., Shcherbakov, Sergey V.
• Format: Article
• Language: English
• Subjects: Aluminum gallium arsenides; Electron gas; Field effect transistors; Gain; Gallium arsenide; Heterostructures; high-electron-mobility transistors (HEMTs); Hot electrons; Indium gallium arsenides; Logic gates; Millimeter wave transistors; Millimeter waves; MODFETs; PHEMTs; Power generation; power transistors; Quantum wells; semiconductor device doping; Semiconductor devices; Space charge; Transconductance; Transistors
• ISSN: 0018-9383; 1557-9646
• DOI: 10.1109/TED.2020.3038373

In this article, we present GaAs millimeter-wave pseudomorphic high-electron-mobility transistor (pHEMT) using sophisticated AlGaAs-InGaAs-GaAs heterostructure with an In 0.22 Ga 0.78 As quantum well located inside an external quantum well formed by space charge regions in AlGaAs layers. In a heterostructure with this design, high mobility [5800 cm 2 /( \text {V}\cdot \text {s} )] and high density ( {4.7}\times {10}^{{12}} cm ^{-{2}} ) of two-dimensional electron gas at 300 K were obtained. The localization of hot electrons in an external quantum well leads to an increase in their drift velocity and to enhance the dc and RF performances of the device. A field-effect transistor based on such a heterostructure with a T-gate of 0.14~\mu \text{m} in length shows a specific current density of about 0.7 A/mm, transconductance of about 250 mS/mm, gate-drain breakdown voltage in the range 23-31 V, which corresponds to more than 2 W/mm specific output RF power according to a simple estimate. The transistor demonstrates impressive RF characteristics, the maximum stable gain (MSG) of more than 15 dB at 40 GHz and more than 10 dB at 67 GHz, {f}_{t} = {45} GHz and {f} _{\text {max}} = {250} GHz. The MSG at 40 GHz increases with increasing distance between the gates in the drain and is almost constant in the range 25-55 GHz.