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A 1 × 8 MEMS (micro-electronic mechanical system(-based flexible integrated optical device with optical switch and variable optical power attenuating functions has been proposed to optimally serve optical fiber-based networking applications.The device manipulates the light with binary-slope mirrors driven by compound electrostatic actuator. The optical models for switching and attenuating are investigated, respectively. Performances of the fabricated devices assembled with ball-lensed fibers are measured and discussed. Measurements reveal that the insertion loss of the device is less than 2.8 dB and the controllable attenuation range is up to 39 dB, respectively. Moreover, polarization-dependent loss is less than 0.8 dB in the whole attenuation range. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:231-236, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27293 [ABSTRACT FROM AUTHOR]

This paper reports a micro electro mechanical system (MEMS) 16×16 free space optical switch based on high-reflectivity mirrors. The mirror monolithically integrated with the fiber grooves can enlarge its rotation angles up to 90°, and keep this as a steady state to steer the optical signal. The reflectivity of the mirror is measured to be 93.1 ∼ 96.3%. The smallest fiber-mirror-fiber insertion loss is 2.1 dB by utilizing optiFocusTM collimating lensed fibers. Moreover, only about ±0.01 dB oscillating amplitude of insertion loss is provoked after the device is tested for 15 min for 5 ∼ 90 Hz in the vertical vibration amplitude of 3 mm. In addition, excellent antifatigue performance of the mirror, which can endure more than 109 cycles of actuation, has been proven. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 3012–3016, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23879 [ABSTRACT FROM AUTHOR]

We have developed a novel (silicon-on-insulator (SOI), microelectromechanical systems (MEMS)) SOI–MEMS technology combined with anodic bonding process. A metal layer on the glass substrate can provide out-of-plane electrodes and interconnects. More importantly, a wafer-level package of mechanical structures constructed by the top layer of the SOI wafer can be formed by the glass substrate and the substrate layer of the SOI wafer simultaneously. The package can protect fragile mechanical structures during post-release processes, such as dicing, mounting and wire bonding as an ordinary IC wafer. In addition, the wafer-level package can directly provide a specialized package, such as a vacuum package for gyroscopes. No special process other than micromachining is needed. [Copyright &y& Elsevier]

Abstract: A novel out-of-plane MEMS tunneling accelerometer is designed, fabricated and characterized. ICP process, which can generate large proof mass, is used for the first time to fabricate an out-of-plane tunneling accelerometer. To reduce the high Hooke''s constant in out-of-plane direction of the ICP etching structure, the beams and the proof mass are dry-etched by double mask ICP process, which reduce the Hooke''s constant, thereby enhance the sensitivity of the device. The tunneling current of open loop is tested in the air by HP4145B semiconductor analyzer, which verifies the presence of tunneling current and shows the needed driving voltage. The close-loop test shows sensitivity of 811mV/g for feedback voltage (the sensitivity of actuate voltage is about 200mV/g) and nonlinearity of 1% in the measurement range of 0 to +1g. The spectrum measurement is performed in general environment and the resolution of the device is 0.5mg/rtHz (1.25¿100Hz), which shows better low frequency property. [Copyright &y& Elsevier]

Abstract: Corrosion of polysilicon occurs in the hydrofluoric acid (HF), which may change the surface morphology, film thickness and even its mechanical strength; furthermore, long time exposure to HF and the presence of Au metallization appear to promote this corrosion. This unusual phenomenon was observed during the releasing of the clamped–clamped beams with a capacitive gap of 100nm, where obvious color change of the surface polysilicon was revealed. Then the influence on electrical performance of the structure was evaluated as well as the relationship between the maximum releasing time and the concentration of HF acid. After that, a novel protective coating was developed to prevent the corrosion. Parylene was demonstrated to be an effective protection mask in HF wet-etching process, where thickness dominated the yield because parylene film swelled in HF etchant. With a parylene protection layer of 0.5–2μm, Al pads can withstand 40min exposure to 40% HF. Finally, a parylene layer of 2μm was deposited and patterned on top of the metal electrode, which proved to be very effective for isolating the polysilicon from galvanic corrosion during releasing. [Copyright &y& Elsevier]

This paper presents the compatibility of ZnO piezoelectric films with the process of micromachining. As a reactive material, ZnO films are sensitive to temperature, acids, bases, and even water. These films may easily be damaged in the subsequent process steps. Therefore, different from most of the present investigations that focus on how to fabricate ZnO films with good performance, this paper discusses how to protect ZnO films against degradation in subsequent micromachining processes. The main micromachining processes related to ZnO films, including cleaning, photolithography, etching, photoresist stripping, metal layer patterning, passivation and dielectric layer deposition, and reaction ion etching (RIE), are investigated. How these subsequent micromachining processes change ZnO films performance and how to minimize or avoid such performance changes is presented. Some suggestions about the subsequent micromachining process steps are given. [Copyright &y& Elsevier]