Exploring the underlying mechanisms of ferroelectric behavior in metal-doped aluminum nitride: an in-depth review

This review explores the intricate relationship between metal doping and the polarization-switching dynamics of wurtzite-phase aluminum nitride (AlN) thin films. We examine how the dopant type, concentration, and resulting crystal structure affect the ferroelectric characteristics of AlN. Particular emphasis is placed on scandium-doped AlN (AlScN), a leading candidate for next-generation ferroelectric applications. We investigate the fundamental mechanisms underlying polarization switching, emphasizing the roles of local chemical interactions, structural modifications, and domain wall dynamics. In addition, we present a comparative analysis of key synthesis techniques - including magnetron sputtering, molecular beam epitaxy, atomic layer deposition, and pulsed laser deposition - highlighting their respective advantages and limitations in fabricating high-quality ferroelectric films. By elucidating the core principles governing ferroelectricity in doped AlN, this review provides valuable insights for the design and optimization of advanced ferroelectric devices aimed at improving performance and energy efficiency.