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A batch- compatible integration of micro- electro- mechanical systems ( MEMS) with nanoscale objects is demonstrated using the example of a gripping device with nanoscale end- effectors. The proposed nanofabrication technique is based on creating a certain number of nanowires/ ribbons on a planar surface, each with a known orientation, using self- assembled crack networks as a template. Since both the location and orientation of the nanowires/ ribbons are known, the gripping device can be lithographically transferred on to the substrate ensuring full integration of MEMS with nanoscale end- effectors. Two nanowires/ ribbons are attached to each MEMS solely at desired locations with a desired inclination in contrast to most other self- assembly- based techniques of growing nanoscale objects. Challenges unique to MEMS fabrication are encountered raising process requirements beyond those of the simple electrode - nanowire integration. With issues related to yield and end- effector geometry remaining to be studied further, the method proposes a true batch fabrication for nanoscale objects and their integration with MEMS, which does not require the use of nano- lithographic techniques.

A deep reactive ion etch (DRIE) process for fabrication of high aspect ratio trenches has been developed. Trenches with aspect ratios exceeding 20 and vertical sidewalls with low roughness have been demonstrated. The process has successfully been used in the fabrication of silicon-on-insulator (SOI) released comb drive based resonators and tunable capacitors for MEMS applications. Brief characterizations of the devices are presented.

This paper presents experimental results on MEMS metallic add-on post-fabrication effects on complementary metal oxide semiconductor (CMOS) transistors. Two versions of add-on processing, that use either e-beam evaporation or magnetron sputtering, are compared through investigation of the electrical parameters of n-channel and p-channel transistors. The magnetron sputtering technique is shown to be compatible with standard CMOS electronics without any restriction of the metal types and annealing requirements.

A micro electromechanical tunable capacitor with a low control voltage, a wide tuning range and high electrical quality factor is presented with detailed characterizations. A 50μm thick single-crystalline silicon layer was etched using deep reactive ion etching (DRIE) for obtaining high-aspect ratio (>20) parallel comb-drive structures with vertical sidewalls. Consisting of only one lithographic mask step, the process sequence can be completed in a short time. Having 1 pF of nominal capacitance, the device offers an electrical quality factor of 100 at 100MHz and a self resonance at 4.08 GHz, enabling the usage as a passive component in the RF band. The mechanical settling time of the varactor is measured to be 200 μs in ambient air. For control voltages ranging from 1.5V to 5V, tuning ratios of 2:1, 1.7:1 and 1.5:1 are obtained from different capacitor designs. It was found that the device is a suitable passive component to be used in band-pass filtering, voltage controlled oscillator or impedance matching applications on the very high frequency(VHF) and ultra high frequency (UHF) bands.

We present a microelectromechanical tunable capacitor with a low control voltage, a wide tuning range and adequate electrical quality factor. The device is fabricated in a single-crystalline silicon layer using deep reactive ion etching (DRIE) for obtaining high-aspect ratio (> 20) parallel comb-drive structures with vertical sidewalls. The process sequence for fabrication of the devices uses only one lithographic masking step and can be completed in a short time. The fabricated device was characterized with respect to electrical quality factor, tuning range, self-resonance frequency and transient response and it was found that the device is a suitable passive component to be used in impedance matching applications, band-pass filtering or voltage controlled oscillators in the Very High Frequency (VHF) and Ultra High Frequency (UHF) bands.

We present the first SU-8 based piezoresistive mechanical sensor. Conventionally, silicon has been used as a piezoresistive material due to its high gauge factor and thereby high sensitivity to strain changes in a sensor. By using the fact that SU-8 is much softer than silicon and that a gold resistor is easily incorporated in SU-8, we have proven that a SU-8 based cantilever sensor is almost as sensitive to stress changes as the silicon piezoresistive cantilever. We demonstrate the chip fabrication, and characterization with respect to sensitivity, noise and device failure.