Microelectromechanical systems having stored charge and methods for fabricating and using same
Many inventions are disclosed. Some aspects are directed to MEMS, and/or methods for use with and/or for fabricating MEMS, that supply, store, and/or trap charge on a mechanical structure disposed in a chamber. Various structures may be disposed in the chamber and employed in supplying, storing and/or trapping charge on the mechanical structure. In some aspects, a breakable link, a thermionic electron source and/or a movable mechanical structure are employed. The breakable link may comprise a fuse. In one embodiment, the movable mechanical structure is driven to resonate. In some aspects, the electrical charge enables a transducer to convert vibrational energy to electrical energy, which may be used to power circuit(s), device(s) and/or other purpose(s). In some aspects, the electrical charge is employed in changing the resonant frequency of a mechanical structure and/or generating an electrostatic force, which may be repulsive.
1. A method for use in association with an electromechanical device having a mechanical structure, the method comprising:
depositing a sacrificial layer over the mechanical structure;
depositing a first encapsulation layer over the sacrificial layer;
forming at least one vent through the first encapsulation layer to allow removal of at least a portion of the sacrificial layer;
removing at least a portion of the sacrificial layer to form the chamber;
depositing a second encapsulation layer over or in the vent to seal the chamber;
supplying electrical charge to at least one portion of the mechanical structure; and
storing at least a portion of the electrical charge on the at least one portion of the mechanical structure after depositing the second encapsulation layer and for a period of at least one day.
2. The method of claim 1 , wherein the first encapsulation layer comprises a polycrystalline silicon, amorphous silicon, germanium, silicon/germanium or gallium arsenide.
3. The method of claim 1 , wherein the second encapsulation layer comprises polycrystalline silicon, amorphous silicon, silicon carbide, silicon/germanium, germanium, or gallium arsenide.