| abstract |
A method for adjusting with high precision the width of gaps between micromachinednstructures or devices in an epitaxial reactor environment. Providing a partially formednmicromechanical device, comprising a substrate layer, a sacrificial layer includingnsilicon dioxide deposited or grown on the substrate and etched to create desired holesnand/or trenches through to the substrate layer, and a function layer deposited on thensacrificial layer and the exposed portions of the substrate layer and then etched tondefine micromechanical structures or devices therein. The etching process exposesnthe sacrificial layer underlying the removed function layer material. Cleaningnresidues from the surface of the device, then epitaxially depositing a layer of gapnnarrowing material selectively on the surfaces of the device. The selection ofndeposition surfaces determined by choice of materials and the temperature andnpressure of the epitaxy carrier gas. The gap narrowing epitaxial deposition continuesnuntil a desired gap width is achieved, as determined by, for example, an opticalndetection arrangement. Following the gap narrowing step, the micromachinednstructures or devices may be released from their respective underlying sacrificialnlayer. |