Dispersion Characteristics of ScAlN and ScAlGaN HEMTs by Pulsed I-V Measurements

Kelson Chabak, Air Force Research Laboratory
Cathy Lee, Qorvo Inc.
Yu Cao, Raytheon IDS Microelectronics, Novati Technologies, Inc. IQE
Andy Xie, Qorvo
Edward Beam, QORVO
Kyle Liddy, KBR
Antonio Crespo, AFRL
Dennis Walker, Air Force Research Laboratory
Robert Fitch, AFRL
James Gillespie, Air Force Research Laboratory
Andrew Green, Air Force Research Laboratory

We report the dispersion characteristics of ScAlN/GaN high-electron-mobility transistors (HEMTs) with various epitaxial designs. Devices were fabricated on both ternary (ScAlN) and quaternary (ScAlGaN) materials. The effects of a GaN capping layer was also investigated. We report similar DC and RF performance for all wafers, but significantly worse dispersion which occurs on the quaternary samples. We observe a total gate and drain lag for the ScAlN wafer to be 49% while the ScAlGaN with and without the GaN cap had 10 and 12% dispersion, respectively.

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