Epitaxial high-K barrier AlBN/GaN HEMTs
Abstract
We report a polarization-induced 2D electron gas (2DEG) at an epitaxial AlBN/GaN heterojunction grown on a SiC substrate. Using this 2DEG in a long conducting channel, we realize ultra-thin barrier AlBN/GaN high electron mobility transistors that exhibit current densities > 0.25 A/mm, clean current saturation, a low pinch-off voltage of −0.43 V, and a peak transconductance of ∼0.14 S/mm. Transistor performance in this preliminary realization is limited by the contact resistance. Capacitance–voltage measurements reveal that introducing ∼7% B in the epitaxial AlBN barrier on GaN boosts the relative dielectric constant of AlBN to ɛrAlBN∼16, higher than the AlN dielectric constant of ɛrAlN∼9. Epitaxial high-K barrier AlBN/GaN HEMTs can thus extend performance beyond the capabilities of current GaN transistors.
Article Details
Journal Info
Applied Physics Letters
American Institute of Physics
Authors (11)
Chandrashekhar Savant
Department of Materials Science and Engineering, Cornell University 2 , Ithaca, New York 14853,
Thai-Son Nguyen
Department of Materials Science and Engineering, Cornell University 2 , Ithaca, New York 14853,
Kazuki Nomoto
School of Electrical and Computer Engineering, Cornell University 3 , Ithaca, New York 14850,
Saurabh Vishwakarma
School for Engineering of Matter, Transport and Energy, Arizona State University 3 , Tempe, Arizona 85287,
Siyuan Ma
Department of Chemistry and the MOE Key Lab of Spectrochemical Analysis & Instrumentation, College of Chemistry and Chemical Engineering
Akshey Dhar
Department of Materials Science and Engineering, Cornell University 1 , Ithaca, New York 14853,
Yu-Hsin Chen
Joseph Casamento
David J. Smith
Department of Physics, Arizona State University 1 , Tempe, Arizona 85287,
Huili Grace Xing
Institute of Materials and Systems for Sustainability, Nagoya University 1 , Nagoya 464-8601,
Debdeep Jena
School of Electrical and Computer Engineering, Cornell University 2 , Ithaca, New York 14853,