Plasma etch techniques for fabricating silicon structures from a substrate

Abstract

Provided is a method for producing a silicon element. A substrate configuration is provided that includes a silicon layer having a first face and a thickness corresponding to a specified thickness of the silicon element to be formed. The configuration includes a layer of an electrically-insulating material located below and adjacent to the silicon layer. A substantially vertical trench is etched from the first face in the silicon layer to a depth that exposes the insulating layer. Then the trench in the silicon layer is exposed to a gaseous environment that is reactive with silicon, to substantially lateral etch the silicon layer preferentially at the depth of the insulating layer along a surface of the insulating layer. This lateral etch is continued for a duration that results in release of a silicon element over the insulating layer. Also provided is a process for etching an angled trench in a silicon layer. Here, a substrate configuration is provided including a first silicon layer having at least one trench etched through the first silicon layer, and layer of an electrically-insulating material located below and adjacent to the silicon layer. The insulating layer includes an aperture that is located at a non-central location with respect to the trench and that corresponds to a prespecified trench angle. Included is a second silicon layer, in which the angled trench is to be formed, below and adjacent to the insulating layer. The trench in the first silicon layer is exposed to a gaseous environment that is reactive with silicon to etch that region of the second silicon layer that is exposed by the aperture in the insulating layer to a selected angled trench depth and prespecified trench angle.

Dependencies are inferred from the claim text.