Saturday 01 March 2025
The pursuit of faster, more efficient data processing has long driven innovation in computing architecture. One promising approach is the development of non-volatile memory technologies, which can store and retrieve data quickly without the need for power-hungry batteries or slow mechanical mechanisms. Among these, ferroelectric materials have shown great potential due to their unique ability to maintain a polarization state even when an electric field is removed.
Ferroelectric AlScN thin films are a particularly exciting area of research, as they offer a combination of high polarization and low leakage currents that make them well-suited for use in non-volatile memory applications. However, the synthesis of these materials has proven to be a significant challenge, with previous methods often resulting in films with compromised properties.
Researchers at Empa, Switzerland, have made significant strides in this area by developing a novel synthesis approach using high-power impulse magnetron sputtering (HiPIMS). This technique allows for the deposition of AlScN thin films with enhanced polarization and low leakage currents, making them more suitable for use in non-volatile memory devices.
The team’s method involves depositing the AlScN films on silicon substrates using a combination of argon and nitrogen gases. By carefully controlling the flow rates and pressure during the deposition process, they were able to achieve a high degree of texture and crystallinity in the resulting films. This was facilitated by the use of a synchronized bias pulse, which helped to enhance adatom mobility at low temperatures.
The resulting films exhibited significantly improved properties compared to previous methods. The team found that the polarization values of the AlScN films were comparable to those of state-of-the-art materials, with remanent polarization values reaching as high as 158-172 microcoulombs per square centimeter. Additionally, the leakage current densities were found to be extremely low, making these films well-suited for use in non-volatile memory applications.
The researchers also investigated the effects of substrate bias and scandium concentration on the properties of the AlScN films. They found that increasing the negative bias during deposition led to greater ion bombardment, which resulted in more compressive stress in the film. The team also observed a significant impact of scandium concentration on the polarization values, with higher concentrations leading to increased polarization.
To further evaluate the potential of these materials, the researchers deposited isolated samples with homogeneous scandium concentrations and characterized their properties using piezoresponse force microscopy (PFM).
Cite this article: “High-Performance Ferroelectric AlScN Thin Films Synthesized via HiPIMS”, The Science Archive, 2025.
Ferroelectric, Alscn, Thin Films, Non-Volatile Memory, Hipims, Magnetron Sputtering, Polarization, Leakage Current, Silicon Substrates, Piezoresponse Force Microscopy
