Strained GaN Quantum-Well FETs on Single Crystal Bulk AlN Substrates

Meng Qi; Guowang Li; Satyaki Ganguly; Pei Zhao; Xiaodong Yan; Jai Verma; Bo Song; Mingda Zhu; Kazuki Nomoto; Huili Xing; Debdeep Jena

doi:10.1063/1.4975702

arXiv · 1611.08914

Strained GaN Quantum-Well FETs on Single Crystal Bulk AlN Substrates

Meng Qi·Guowang Li·Satyaki Ganguly·Pei Zhao·Xiaodong Yan·Jai Verma·Bo Song·Mingda Zhu·Kazuki Nomoto·Huili Xing·Debdeep Jena

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Abstract

We report the first realization of molecular beam epitaxy grown strained GaN quantum well field-effect transistors on single-crystal bulk AlN substrates. The fabricated double heterostructure FETs exhibit a two- dimensional electron gas (2DEG) density in excess of 2x10^13/cm2. Ohmic contacts to the 2DEG channel were formed by n+ GaN MBE regrowth process, with a contact resistance of 0.13 Ohm-mm. Raman spectroscopy using the quantum well as an optical marker reveals the strain in the quantum well, and strain relaxation in the regrown GaN contacts. A 65-nm-long rectangular-gate device showed a record high DC drain current drive of 2.0 A/mm and peak extrinsic transconductance of 250 mS/mm. Small-signal RF performance of the device achieved current gain cutoff frequency fT~120 GHz. The DC and RF performance demonstrate that bulk AlN substrates offer an attractive alternative platform for strained quantum well nitride transistors for future high-voltage and high-power microwave applications.

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Meng Qi, Guowang Li, Satyaki Ganguly, Pei Zhao, Xiaodong Yan, Jai Verma, Bo Song, Mingda Zhu, Kazuki Nomoto, Huili Xing, Debdeep Jena. 2016-11-27. Strained GaN Quantum-Well FETs on Single Crystal Bulk AlN Substrates. https://doi.org/10.1063/1.4975702

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