685725 event 1760562370 1760562440 <![CDATA[Ph.D. Proposal Oral Exam - Nashrah Afroze]]> Title:  Thermal Reliability with Oxygen reservoir layer and Atomic-Scale Insights in Fluorite ferroelectrics for memory-on-logic applications

Committee: 

Dr. Khan, Advisor 

Dr. Yu, Chair

Dr. Datta

]]> The objective of this study is to advance ferroelectric memory for AI-era, memory-bound systems by uniting interface engineering with atomic-scale characterization. Motivated by growing bottlenecks in capacity, bandwidth, and reliability, we focus on ferroelectric devices and demonstrate that inserting an ultrathin WO3-x oxygen-reservoir layer at the ferroelectric/electrode interface activates a thermally driven self-healing mechanism that markedly improves endurance. By tuning the oxygen content of WO3-x, we further achieve nearly wake-up-free operation at 125˚C—the JEDEC qualifying temperature for 3D integration—while preserving the orthorhombic ferroelectric phase under thermal stress, in agreement with first-principles predictions. Complementing these device-level advances, plan-view scanning transmission electron microscopy directly visualizes nanoscale polarization textures in ultrathin ferroelectrics, revealing sub-nanometer ferroelectric domains bounded by alternating head-to-head and tail-to-tail 180˚ domain walls. These highly charged walls map the dipolar self-organization landscape that governs polarization switching in HfO₂-based ferroelectrics. Collectively, the results establish a materials-todevices pathway for reliable, high-temperature, wake-up-free ferroelectric operation and provide micro-to-macro insight that informs process/design co-optimization for nonvolatile tiers (e.g., Fe-NAND, FeRAM, FeFETs) in memory-on-logic architectures.

]]> <![CDATA[]]> https://teams.microsoft.com/l/meetup-join/19%3ameeting_YjI1MDMxM2UtYjBlYi00YWUzLWE2OTktZmY4OWQ3MWJmNjcx%40thread.v2/0?context=%7b%22Tid%22%3a%22482198bb-ae7b-4b25-8b7a-6d7f32faa083%22%2c%22Oid%22%3a%22caac1375-b515-4160-8f2d-e92b36099b24%22%7d 434371 1788 100811 1808