Microelectromechanical device including an encapsulation layer of which a portion is removed to expose a substantially planar surface having a portion that is disposed outside and above a chamber and including a field region on which integrated circuits are formed, and methods for fabricating same

A method of manufacturing a microelectromechanical device, the method comprising:

• forming a micromachined mechanical structure on top of a substrate;
• providing a sacrificial layer over the micromachined mechanical structure;
• disposing a first encapsulation layer over at least a portion of the sacrificial layer, at least a portion of the micromachined mechanical structure, and at least a portion of the substrate;
• forming a plurality of vents in the first encapsulation layer;
• removing the sacrificial layer through the plurality of vents to release at least a portion of the micromachined mechanical structure, thereby forming a chamber, wherein:
• a surface of the first encapsulation layer forms a wall of the chamber,
• at least a portion of the micromachined mechanical structure is disposed in the chamber, and
• after the sacrificial layer is removed, no intervening layers reside between the micromachined mechanical structure and the first encapsulation layer;
• and
• disposing a second encapsulation layer over the first encapsulation layer to fill the plurality of vents, thereby sealing the chamber, wherein:
• no intervening layers reside between the first encapsulation layer and the second encapsulation layer, and
• the first encapsulation layer and the second encapsulation layer comprise the same material.