In Situ STEM with Electrical Bias for Next-Generation Microelectronics Systems

For emerging memory and logic applications, materials with phase transitions that control their electronic properties are actively pursued. Thus, understanding dynamic processes of the phase transitions is indispensable for next-generation microelectronics applications as they determine the microstructure and consequently the desirable electronic properties. In situ (scanning) transmission electron microscopy ((S)TEM) uniquely captures short-lived transient states and time-dependent changes in structure-property relations at atomic resolution during the phase transition, providing important information and opportunities to engineer material properties.

In this talk, I will discuss several examples of nanoscale phase transitions in which the changes in structure and properties are probed by in situ (S)TEM (cooling, liquid synthesis, heating, and electrical biasing). These examples will include discovery of metastable and transient intermediate phases during synthesis of nanomaterials, emergence of new electronic phases via intercalation in two-dimensional (2D) materials, and effects of nanoscale confinement on phase transitions of 2D quantum materials. In each example, unexpected nanoscale effects and the unique advantages of in situ S/TEM will be highlighted. Looking to the future, the need for in situ cryo STEM with electrical bias to study nanoscale quantum materials will be emphasized.