Large Stroke MEMS Linear Actuators and Advanced Interconnects

Abstract

Linear actuators are used throughout the world in many applications. Microelectromechanical Systems (MEMS) linear actuators use semiconductor fabrication processes that are capable of producing small feature sizes and high precision movements. This dissertation will examine two types of mesoscale linear actuators that exhibit a very large stroke compared to the size in addition to high precision positioning. These MEMS linear actuators are designed as building blocks that can act as a stage for numerous possible applications. In addition to the linear actuators, two interconnect designs will be examined. Molybdenum is an intriguing material for use as interposers due to the close match to silicon of thermal conductivity and coefficient of thermal expansion. For molybdenum to be used as an interposer, through molybdenum vias (TMVs) would be required and is the first interconnect examined in this dissertation. The second is superconducting flip-chip bumps consisting of tin-lead and indium. These superconducting bumps or pillars can be fabricated at heights that allow for physical isolation between the substrates without the extra loss due to the superconducting material that make up the pillars.