Ferroelectric AlScN thin films with enhanced polarization and low leakage enabled by high-power impulse magnetron sputtering

The demand for efficient data processing motivates a shift toward in-memory computing architectures. Ferroelectric materials, particularly AlScN, show great promise for next-generation memory devices. However, their widespread application is limited due to challenges such as high coercive fields, le...

Full description

Saved in:
Bibliographic Details
Main Authors: Federica Messi, Jyotish Patidar, Nathan Rodkey, Christoph W. Dräyer, Morgan Trassin, Sebastian Siol
Format: Article
Language:English
Published: AIP Publishing LLC 2025-05-01
Series:APL Materials
Online Access:http://dx.doi.org/10.1063/5.0267904
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The demand for efficient data processing motivates a shift toward in-memory computing architectures. Ferroelectric materials, particularly AlScN, show great promise for next-generation memory devices. However, their widespread application is limited due to challenges such as high coercive fields, leakage currents, and limited stability. Our work introduces a novel synthesis approach for ferroelectric AlScN thin films using high-power impulse magnetron sputtering (HiPIMS). Through a combinatorial study, we investigate the effect of scandium content and substrate bias on the ferroelectric properties of AlScN films deposited using metal-ion synchronized (MIS) HiPIMS. Leveraging the high ionization rates of HiPIMS and optimally timed substrate bias potentials, we enhance the adatom mobility at low temperatures. Our films exhibit a high degree of texture and crystallinity as well as low roughness at temperatures as low as 250 °C. Most importantly, the films exhibit coercive fields comparable to state-of-the-art values (5 MV/cm) with significantly enhanced remanent polarization (158–172 μC/cm2). Notably, the remanent polarization remains stable across varying scandium concentrations. We further evaluate cycling stability and leakage current to assess suitability for memory applications. This study demonstrates HiPIMS as a scalable and CMOS compatible technique for synthesizing high-quality ferroelectric AlScN films, paving the way for their application in non-volatile memory applications.
ISSN:2166-532X