Defect Engineered Functional Properties in Ferroelectric Aluminum Nitride

The recent discovery of ferroelectricity in cation-substituted aluminum nitride has sparked significant interest within the ferroelectrics community. Aluminum nitride boasts highly desirable properties such as a wide bandgap, excellent electrical resistance, exceptional thermal conductivity, and an extremely high phase transition temperature, while also being compatible current semiconductor fabrication workflows. However, its inherent high coercive field poses a challenge for its deployment in low-energy applications. This study investigates strategies to mitigate the coercive field in boron-substituted aluminum nitride, focusing on ion irradiation and the effects of varying thin film thickness. Optical spectroscopy, scanning transmission electron microscopy, and piezoresponse force microscopy are employed to analyze the influence of defects on the coercive field. By elucidating these mechanisms, this research aims to advance our understanding of coercive field reduction strategies in boron-substituted aluminum nitride, paving the way for its broader integration into the next generation of high power electronic and optoelectronic devices.