• Proceedings of the KIEE Conference
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• 1996.11a
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• pp.425-427
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• 1996

New fabrication technique was developed to make three dimensional silicon microstructure with five fold vertical steps through entire wafer thickness. Each step is pre-defined on multiply stacked thermal oxide and silicon nitride (O/N) layers by photolithographies. Multi-stepped silicon microstructure is formed by anisotropic etch in aqueous KOH solution with the patterned nitride film as masking layer. Fabricated microstructure consists of four $16{\mu}m$ thick flexural spring beams, $290{\mu}m$ thick proof mass, mesas for overrange stop with $10{\mu}m$ height from the surface of the proof mass, and the other mesas and V grooves used for assembling this structure to the packaging frame of pendulous servo accelerometer. Using the numerical finite element method (FEM) simulator: ABAQUS, mechanical characteristics of the fabricated microstructure by the developed technique was compared with those of the same structure processed by one step silicon bulk etch followed by oxidation and patterning the etched region.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.2
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• pp.408-413
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• 1996

A self-diagnostic, air-damped, piezoresitive, cantilever-beam microaccelerometer has been designed, fabricated and tested for applications to automotive electronic airbag systems. A skew-symmetric proof-mass has been designed for self-diagnostic capability and zero transverse sensitivity. Two kinds of multi-step anisotropic etching processes are developed for beam thickness control and fillet-rounding formation, UV-curing paste has been used for sillicon-to-glass bounding. The resonant frequency of 2.07kHz has been measured from the fabricated devices. The sensitivity of 195 $\mu{V}$/g is obtained with a nonlinearity of 4% over $\pm$50g ranges. Flat amplitude response and frequency-proportional phase response have been obserbed, It is shown that the design and fabricaiton methods developed in the present study yield a simple, practical and effective mean for improving the performance, reliability as well as the reproducibility of the accelerometers.