Characterization of Metal-Insulator-Transition (MIT) Phase Change Materials (PCM) for Reconfigurable Components, Circuits, and Systems.

摘要

Many microelectromechanical systems (MEMS) use metal contact micro-switches as part of their reconfigurable device design. These devices utilize a mechanical component that can wear down and fail over time. Metal insulator transition (MIT) materials, also known as phase change materials (PCMs), exhibit a reversible transition that can be used to replace the mechanical comp nent in reconfigurable devices. In the presence of a thermal or electric field stimuli, the PCMs will transition back and forth between a crystalline and amorphous state. During this transformation, the resistivity, reflectivity, and Young's modulus of the material drastically change. This research effort focuses on characterizing the stimuli required to transition germanium telluride (GeTe) and vanadium oxide (VOx). To do this, test structures were designed and microfabricated in AFIT's class 1000 cleanroom. The resistivity of the GeTe films underwent a volatile transition from 1.4E3Ohm-cm down to 2.28Ohm- cm and a nonvolatile transition from 1.4E3Ohm-cm to 2.43E-3Ohm-cm when a thermal stimulus was applied. The reflectivity of the film also changed significantly when crystallized, increasing over 30%. Lastly, the Young's modulus was measured and showed a 28% change during crystallization. After the materials were characterized, reconfigurable devices were designed to utilize the phase change properties of the PCMs.