ESE PhD Thesis Defense – “Design and Characterization of AlScN-Based Ferroelectric Devices for Non-Volatile Memory Applications”

Ferroelectric materials have emerged as promising candidates for next-generation non-volatile memory technologies due to their intrinsic remnant polarization and fast switching dynamics. Among them, aluminum scandium nitride (AlScN) stands out for its CMOS compatibility, low growth temperature, exceptional thermal stability and high remnant polarization compared to conventional perovskite and hafnia-based ferroelectrics.

In this dissertation, I present a comprehensive study of AlScN-based ferroelectric devices for non-volatile memory applications. I first demonstrate ferroelectric field-effect transistors (FeFETs) by integrating AlScN with 2D materials, where the Sc composition in AlScN is controlled. Through systematic electrical characterization, including current–voltage (I–V), polarization–voltage (P–V) loops, and pulsed positive up negative down (PUND) measurements, I elucidate device physics, endurance, and wake-up/fatigue behavior. By engineering the contact interface, I further realize n-type, p-type, and ambipolar FeFETs with enhanced ferroelectric gating efficiency and substantially improved on-state current.

Next, I investigate highly scaled AlScN-based ferroelectric diodes (Fe-diodes) and highlight their potential for high-density memory integration. Taken together, these studies establish AlScN as a robust material platform for ferroelectric device technologies, bridging fundamental materials science with device- and circuit-level opportunities in memory and beyond.