Self-sealing membrane for MEMS devices

摘要

Embodiments of the present disclosure are related to MEMS devices having a suspended membrane that are secured to and spaced apart from a substrate with a sealed cavity therebetween. The membrane includes openings with sidewalls that are closed by a dielectric material. In various embodiments, the cavity between the membrane and the substrate is formed by removing a sacrificial layer through the openings. In one or more embodiments, the openings in the membrane are closed by depositing the dielectric material on the sidewalls of the openings and the upper surface of the membrane.

主权项

1. A method of forming a flexible membrane, comprising:
forming a sacrificial layer over a surface of a substrate; forming a conductive electrode over the sacrificial layer, the conductive electrode including a plurality of openings with sidewalls; forming a cavity between the conductive electrode and the substrate by removing the sacrificial layer through the plurality of openings in the conductive electrode; and closing the openings by depositing a dielectric material on the sidewalls of the openings and on an upper surface of the portion of the conductive electrode, and continuing to deposit the dielectric material for a time period after the openings are closed to seal the cavity from atmosphere, wherein depositing the dielectric material includes alternatingly directing the dielectric material between a first angle of incidence and a second angle of incidence, the second angle of incidence being different from the first angle of incidence, the deposited dielectric material and the conductive electrode together forming the flexible membrane.