CAREER: High-Temperature Thermal Transport in LPCVD Polysilicon for MEMS

Regents Of The University Of Michigan - Ann Arbor, Ann Arbor MI

Investigators

Abstract

This research program investigates the impact of high-temperature microstructural changes in Low Pressure Chemical Vapor Deposited (LPCVD) polysilicon on microscale thermal transport phenomena in microelectromechanical systems (MEMS). An application of thermal conduction physics, materials science, and silicon micromachining is made for generating new scientific knowledge needed for the design of polysilicon-based thermal sensors and actuators, and for their reliability predictions. To achieve studies at high-temperatures, a novel on-chip instrument is developed using MEMS techniques. The instrument is to measure thermal transport property of polysilicon films and allows for in situ observation of grain size evolution. Based on the acquired experimental data, theoretical work is performed to model thermal transport by accounting for grain size, grain configuration, impurity concentrations, and microstructural kinetics. The developed model is to serve for understanding scaling laws and design rules for polysilicon-based MEMS devices and CMOS transistors. The education program addresses the significant demands on heat transfer education for MEMS engineers with the purpose of preparing students for "optimizing a product design." Using on-campus information technology resources, this program develops a new heat transfer course based on a MEMS thermal design competition. The thermal design project asks student teams to propose a MEMS design that should yield a better figure of merit for a particular device, which is strongly influenced by heat transfer phenomena. The course is designed for senior and graduate students from various engineering programs. A web-page-based instruction is implemented for this course to promote effective communications among the participants.