Ultrafast Phase-Change for Data Storage Applications

Abstract

Phase-change random access memory (PCRAM) is one of the leading candidates for next-generation data-storage devices, but the trade-off between crystallization speed and amorphous-phase stability presents a key challenge. In this thesis, nanoscale effects in phase-change (PC) materials and functional materials were exploited to achieve fast-speed, low-power, and high-endurance in PCRAM cells. Incubations of nanostructural units in PC materials were studied to control the crystallization kinetics by the application of a constant low-voltage. To change the PC mechanisms, nanostructured PC materials were also investigated by controlling feature sizes. Thermal effects in nanoscale PC materials with superlattice-like (SLL) structures were further examined to control the thermal-confinement properties by varying device sizes. To enhance thermal-confinement, thermal properties of nanoscale SLL dielectric materials were studied by varying the number of periods in SLL dielectric. These studies pave the way for achieving a broadly applicable memory device, capable of non-volatile operations beyond GHz data-transfer rates.