Patent ID: 7859067

Claim:
A microelectromechanical device, comprising: a substrate; a chamber; a micromachined mechanical structure at least partially disposed in the chamber; a first encapsulation layer comprising a permeable material having a plurality of pores; and a second encapsulation layer comprising a semiconductor material disposed over the first encapsulation layer and sealing the chamber by filling the plurality of pores; wherein: the first encapsulation layer is disposed over both the micromachined mechanical structure and the substrate; the first encapsulation layer forms at least a portion of a wall of the chamber; the first encapsulation layer comprises a polycrystalline semiconductor material doped with a first impurity with a first conductivity type; the semiconductor material of the second encapsulation layer is doped with a second impurity with a second conductivity type; the first conductivity type is different than the second conductivity type; a portion of the second encapsulation layer having been removed to expose a substantially planar surface; the substantially planar surface is adapted to provide a base upon which integrated circuits are formed; and a first portion of the substantially planar surface is disposed outside and above the chamber and includes a field region comprising a monocrystalline material and upon which the integrated circuits are formed.