Roger T. Howe (Advisor)

Silicon Carbide and Diamond Materials Development for Micro- and Nano-Electromechanical Systems

Jingchun Zhang
Roya Maboudian
Roger T. Howe
David B. Graves
Albert P. Pisano
2007
Microelectromechanical systems (MEMS) are miniature integrated systems including both mechanical and electronic components, which are developed based on silicon integrated circuits technology. The current trend indicates two directions of MEMS technology: (1) a scaling downward to nanometer scale as nanoelectromechanical systems (NEMS); (2) a development of advanced materials that can outperform silicon. The goal of this work is to study and develop the material properties and process flows to realize the...

Resonant Circuits for MEMS Interfaces

Baris Cagdaser
Bernhard E. Boser
Kristofer S.J. Pister
Liwei Lin
Roger T. Howe
2005
This work describes the use of resonant circuits for electrostatic actuation of MEMS devices with low voltage drive electronics. Resonant drive also offers a solution for position sensing and generates a sense signal without the need for a separate sense capacitor. Moreover, an inherent force feedback mechanism limits the drive voltage as the drive capacitor becomes larger and stabilizes parallel-plate actuators beyond the pull-in point of the...

Reactive Ion Etching of Zinc Oxide and Indium-Tin-Oxide

Eric Minami
Richard M. White
Roger T. Howe
1988

Reactive ion etch processes for zinc oxide (ZnO) and indium-tin oxide (TTO) have been characterized under various power, pressure, flow rate, and temperature conditions. We have found that the use of hydrogen iodide (HI) plasma allows 2um features with vertical sidewalls to be pattern in both materials. The etch was selective with respect to Si3N4, SiO2, and Si. In addition, the resistivity of ITO prepared by RF supttering was characterized under different deposition conditions.

Polycrystalline Silicon-Germanium Contact Resistance Study for Integrated MEMS Technology

Marie-Ange Eyoum
Tsu-Jae King
Roger T. Howe
2003

Co-fabrication of surface micromachined micro-electromechanical devices and control electronics is advantageous for reducing cost and improving performance of microsystems[l]- [8]. With the MEMS and electronic circuits on separate chips, the parasitic capacitance and resistance...

Novel Processes for Modular Integration of Silicon-Germanium MEMS with CMOS Electronics

Carrie Wing-Zin Low
Tsu-Jae King Liu
Roger T. Howe
Richard M. White
Oscar D. Dubon Jr.
2007
Equipment control, process development and materials characterization for LPCVD poly-SiGe for MEMS applications are investigated in this work. In order to develop a repeatable process in an academic laboratory, equipment monitoring methods are implemented and new process gases are explored. With the dopant gas BCl3, the design-of-experiments technique is used to study the dependencies of deposition rate, resistivity, average residual stress,...

Micromachined Electrodes for High Performance Capacitive Pressure Sensors

Vikram Shenoy
Roger T. Howe
Liwei Lin
2000

This report discusses the use of silicon micromachining to create a part for subassembly into a high performance capacitive pressure sensor. The micromachined silicon part replaces traditionally machined metal parts. The micromachined parts provide tight control of the gap between the electrode ...

Modulated Infrared Source

Peter Yung-Sen Chen
Richard S. Muller
Roger T. Howe
1993
This project considers the design and fabrication of a modulated microincandescent IR source. To reduce background noise and to improve signal amplification, most infrared applications require a modulated IR output at a fairly high frequency (above 1kHz)....

Integrated Surface Micromachined Frame Microgyroscopes

Moorthi Palaniapan
Roger T. Howe
Albert P. Pisano
Roberto Horowitz
2002
In this work, two different integrated surface-micromachined z-axis vibratory rate gyroscopes are evaluated. Frame microgyroscopes using 'Inside Sense Outside Drive' suspension design were proposed and compared with 'Inside Drive Outside Sense' design. In the 'Inside Sense Outside Drive' frame design, the outer mass (...

Fluidic Self-Assembly of Microfabricated Parts to Substrates Using Capillary Forces

Uthara Srinivasan
Roger T. Howe
Dorian Liepmann
Susan J. Muller
Jeffery A. Reimer
2001
In this work, we present a fluidic microassembly technique which uses capillary forces to self-assemble microparts onto a substrate. We have demonstrated this technique using microfabricated silicon parts and silicon and quartz substrates....

Fatigue of Polycrystilline Silicon in MEMS Devices

Angela S. Choy
Kyriakos Komvopoulos
Albert P. Pisano
Roger T. Howe
1999

A clear understanding of the mechanical properties of the structural materials used in MEMS devices is critical in the design and reliability analysis of these devices. However, it cannot be assumed that macroscale and microscale devices have the same behavior. Macroscale fatigue mathods cannot accurately predict the behavior of microscale devices because at microscale sizes, the structure size is on the same order of magnitude as the grain size of the material. Also, grain boundaries, environmental, and facrications effects, which are negligible on the macroscale, may be significant on...