Electrostatically driven vacuum-encapsulated polysilicon resonators Part I. Design and fabrication

Abstract

Basic design issues and a fabrication process based on surface-micromachining 'techniques for electrostatically driven vacuumencapsulated polysilicon resonators are presented. A novel freeze-drying method that does not require vacuum equipment is presented. Reactive sealing with LPCVD silicon nitride is used to create the evacuated cavity, resulting in cavity pressures close to the deposition pressure. Design issues regarding choice of materials, technology and layout are discussed, First experimental results, including an admittance plot of the one-port resonator and a plot indicating the dependence of the Qfactor on the resonator geometry and ambient pressure, are presented.

Thermal effect on the pull-in instability of functionally graded micro-beams subjected to electrical actuation

“…The devices are typically designed to operate in one or more energy domains due to their unique advantages such as small size, lower power consumption, lower operation cost, increased reliability and higher precision. With MEMS are used more and more widely due to their unique advantages, such as small size, lower power consumption, lower operation cost, increased reliability and higher precision, numerous analytical, numerical and experimental studies have been conducted on the pull-in instability of the MEMS devices [1][2][3][4][5].…”

“…The devices are typically designed to operate in one or more energy domains due to their unique advantages such as small size, lower power consumption, lower operation cost, increased reliability and higher precision. With MEMS are used more and more widely due to their unique advantages, such as small size, lower power consumption, lower operation cost, increased reliability and higher precision, numerous analytical, numerical and experimental studies have been conducted on the pull-in instability of the MEMS devices [1][2][3][4][5].Most recently, the use of functionally graded materials (FGMs) in MEMS structures has been proposed by Craciunescu and Wuttig [6] and Fu et al [7], since FGMs offer many advantages including improved stress distribution, enhanced thermal resistance, higher fracture toughness, and reduced stress intensity factors that make them very attractive in many engineering applications [8]. Specially, Witvrouw and his co-workers [9, 10] developed a multilayer polySiGe deposition process for fabricating MEMS structural layers that fulfill all material and economical requirements.…”

Control of MEMS Vibration Modes With Pulsed Digital Oscillators: Part I—Theory

“…The first three functions ψ 1,2,3 (ξ) (calculated according to (5) for the first three solutions of (6)) are shown in fig. 3 as functions of the axial coordinate.…”

Vacuum packaging technology using localized aluminum/silicon-to-glass bonding

“…In addition, most micromachined resonant devices have very large surface-to-volume ratios and vibrate in a very tight space. For such devices, viscous and squeeze-film damping effects can also reduce their factor [2], [3].…”