Patent ID: 8062497

Claim:
A method of forming a sealed cavity, the method comprising: providing a sacrificial layer onto a substrate lying in a plane; providing a seed layer on the sacrificial layer, the seed layer being formed from an electrically conductive material; providing on the seed layer at least one structure extending in a direction substantially perpendicular to the plane of the substrate, the structure being formed from a non-conductive material; after providing the at least one structure, providing a membrane layer such that the at least one structure is at least partially encompassed by the membrane layer along its height; after providing the at least one structure and the membrane layer, providing a sealing layer on the membrane layer, the sealing layer covering the membrane layer and having one or more openings at the location of the at least one structure; after providing the membrane layer and the sealing layer, removing the at least one structure, hereby forming at least one hole through the membrane layer in a direction substantially perpendicular to the plane of the substrate; removing at least part of the sacrificial layer through the at least one hole, hereby forming a cavity; and sealing the at least one hole in the membrane layer.