Method for Sealing a Micro-Cavity

Abstract

A method for sealing a cavity is disclosed. The method includes depositing a membrane layer on top of a sacrificial layer, etching release holes into the membrane layer, and removing at least a portion of the sacrificial layer through the release holes to form a cavity. Prior to removing the sacrificial layer portion, the method includes producing a narrowing layer on the side walls of the release holes. The narrowing layer can be a sealing layer that seals off the release holes after a reflow step. Alternatively, the narrowing layer can be a layer that does not have a sealing function and is used to narrow the holes, allowing the holes to be sealed without a sealing or other material entering the cavity. The narrowing layer may be deposited by conformal deposition followed by an anisotropic etch or by direct deposition on the side walls of the release holes.

Dependencies are inferred from the claim text.