Date of Award
Summer 2022
Document Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
Department
Electrical and Computer Engineering
First Advisor
Coutu, Ronald A.
Second Advisor
Hayat, Majeed
Third Advisor
Richie, James
Abstract
Microelectromechanical systems (MEMS) switch is considered as a better alternative than the conventional solid-state DC and RF switches due to their low contact resistance approximately 1 Ω, near-zero power consumption approximately 0 W, low insertion loss approximately 0.2 dB, and high isolation approximately -30 dB. However, reliability is a great concern for them to be ubiquitously used by the industry for specific applications. Switching dynamics and microcontact surface physics play the critical role in determining their reliability. A simple, quick, and efficient test fixture is required to study the contact surface physics as well as to optimize the switching dynamics.In this dissertation, we design and assemble a novel, fast, and efficient test fixture to study reliability and performance associated with a MEMS switch. The test fixture consists of an actuation system and a microcontact support structure to mimic a MEMS switch operation. The actuation system is used to provide actuated force, nanometric positioning and precise alignment between the upper and lower microcontact area on three orthogonal axes. The microcontact support structure (MSS) is fabricated using silicon on insulator (SOI) MEMS processing to facilitate efficient post-mortem analysis relevant to contact materials and contact geometry study. To evaluate the test fixture’s performance, we analyze performance of actuators, force sensors and National instrument’s (NI) circuit cards. The test fixture is capable of performing Initial Contact Test (ICT), Cold Switching Test (CST), and Hot Switching Test (HST) which are critical for a MEMS switch reliability testing. The entire test setup is placed in a dry nitrogen (N2) chamber to minimize contact surface contamination. LabView programming is used to automate nano-positioning, actuation and collect microcontact data at the rate of 5 KHz. We fabricate microcontact support structures (MSS) with gold (Au) and ruthenium oxide (RuO) metal contact materials. The contact resistance associated with a RuO on Au microcontact is collected with respect to the contact force, and number of switching cycles. The data collected from the test fixture provides significant information to design a robust and reliable MEMS switch for 5G and beyond as well as for internet of things (IOT) applications.