Research
Prof. Zonghoon Lee’s Atomic-Scale Electron Microscopy Lab
Prof. Zonghoon Lee’s Atomic-Scale Electron Microscopy Lab
Abstract
With the acceleration of the scaling down of integrated circuits, it has become very challenging to fabricate a metal–insulator–metal (MIM) capacitor with a high capacitance density and low leakage current for nanoscale dynamic random access memory. Yttria-stabilized-zirconia (YSZ) thin films, one of the insulators in the constitution of MIM capacitors, have been reported to have various crystal structures from the monoclinic phase to the cubic phase according to different Y doping levels. The electrical characteristics depend on the crystal structure of the YSZ thin film. Here, we report the local crystallization of YSZ thin films via Joule heating and the leakage current induced during in situ transmission electron microscopy biasing tests. We studied the crystallization process and the increase in the leakage current using experimental and simulation results. It is important to understand the relationship between the crystallinity and electrical properties of YSZ thin films in MIM capacitors.
Our research focuses on atomic-scale characterization, design, and synthesis as well as the properties of advanced materials including 2D materials, carbon materials, and soft matter by means of aberration-corrected transmission electron microscopy and spectroscopy. In situ experiments at both the atomic and nano scales are implemented for our study.
Advanced TEM Characterization