This paper describes the fabrication techniques and characterization of silicon dioxide micromechanical components with a layer of porous aluminum oxide which results in novel properties. An aqueous SOL process has been developed to obtain a layer of porous aluminum oxide on the silicon dioxide. The micro-porous surface, so realized, can be used as sensitive moisture and gas detectors. Various parts fabricated in silicon dioxide are cantilever, cross beam, spiral spring and resonator, coated with porous aluminum oxide, and micro-probes, coated with chromium-gold for electrical contacts. This paper also demonstrates the use of the trapezoidal pit etched in silicon during micromachining as a radiation concentrator. The results of derivation of the concentrator efficiency clearly shows the advantage of the reflections from the trapezoidal cavity.
|