Revealing the Defect‐Driven Ferroelectric Mechanisms of Aluminum Nitride
Abstract
ABSTRACT Wurtzite III‐nitride compounds are CMOS‐compatible with widespread industrial interest to exercise ferroelectricity, despite their polar structure being highly resistant to polarization reversal. Here, we induce and tune ferroelectric properties in w‐AlN via direct‐write ion‐beam processing, using nanoscale patterned defect engineering as a post‐growth alternative to conventional cation substitution. Nanometric piezoresponse spectroscopy of the focused He + beam patterned defect concentrations in ferroelectric Al 0.92 B 0.08 N measures a localized 10x enhancement in effective piezoresponse and 40% reduction in switching barrier. The irradiation‐induced point defects convert piezoelectric AlN into a ferroelectric system with site‐saturated nucleation and raise the dielectric susceptibility, switched polarization, and effective piezoelectric coefficient. Enhanced defect‐lattice interactions in AlN increase carrier conduction and phonon scattering loss but preserve long‐range crystallinity. Based on atomistic analysis of nudged elastic band density functional theory calculations and reactive force field simulations, both nitrogen vacancies and defect complexes disrupt bond ordering, facilitating a line‐by‐line low‐barrier switching of pristine AlN.
Article Details
Authors (22)
Bogdan Dryzhakov
Chloe Skidmore
Department of Materials Science and Engineering, The Pennsylvania State University 1 , University Park, Pennsylvania 16802,
Drew Behrendt
Sebastian Calderon
Leonard C. Jacques
Department of Engineering Science & Mechanics The Pennsylvania State University University Park Pennsylvania USA
Erdem Ozdemir
Department of Material Science and Engineering The Pennsylvania State University University Park Pennsylvania USA
John Hayden
Ian Mercer
Department of Materials Science and Engineering The Pennsylvania State University University Park Pennsylvania USA
Ali Mohammadi Dinani
Department of Chemical Engineering The Pennsylvania State University University Park Pennsylvania USA
Ilia Ivanov
Center For Nanophase Materials Sciences Oak Ridge National Laboratory Oak Ridge Tennessee USA
John Lasseter
Center For Nanophase Materials Sciences Oak Ridge National Laboratory Oak Ridge Tennessee USA
Bernadeta Srijanto
Alireza Sepehrinezhad
Department of Engineering Science & Mechanics The Pennsylvania State University University Park Pennsylvania USA
GaUn Jeong
Department of Mechanical Engineering The Pennsylvania State University University Park Pennsylvania USA
Betul Akkopru Akgun
Department of Material Science and Engineering The Pennsylvania State University University Park Pennsylvania USA
Andrew M. Rappe
Adri C. T. van Duin
Department of Materials Science and Engineering, The Pennsylvania State University 1 , University Park, Pennsylvania 16802,
Susan Trolier‐McKinstry
Department of Material Science and Engineering The Pennsylvania State University University Park Pennsylvania USA
Elizabeth C. Dickey
Steven J. Randolph
Center For Nanophase Materials Sciences Oak Ridge National Laboratory Oak Ridge Tennessee USA
Jon‐Paul Maria
Department of Materials Science and Engineering The Pennsylvania State University University Park Pennsylvania USA
Kyle P. Kelley