Micromechanical structure with bonded cover

Abstract

A semiconductor layer having an opening and a MEMS resonator formed in the opening is disposed between first and second substrates to encapsulate the MEMS resonator. An electrical contact that extends from the opening to an exterior of the MEMS device is formed at least in part within the semiconductor layer and at least in part within the first substrate.

1 . (canceled) 
     
     
         2 . A device comprising:
 a first substrate;   a second substrate;   in between the first substrate and the second substrate, at least intermediate layer, the at least one intermediate layer comprising a semiconductor layer patterned to defined a microelectromechanical systems (MEMS) resonant structure, the at least one intermediate layer also providing a frame that encircles the MEMS resonant structure;   wherein the first substrate, the second substrate and the frame cooperate to hermetically seal the MEMS resonant structure within an interior chamber of said device; and   one or more electrical contacts on an exterior of said device, to provide an output signal representing a resonance frequency of the MEMS resonant structure.   
     
     
         3 . The device of  claim 2  wherein the second substrate is bonded to an outermost layer of the at least one intermediate layer, in a manner such that a bonding interface is defined at a region of contact between the second substrate and the outermost layer. 
     
     
         4 . The device of  claim 2  wherein:
 the second substrate has a first surface, which faces towards the first substrate, and a second surface, which faces away from the first substrate: 
 the at least one intermediate layer comprises an electrode which lies in between the first substrate and the first surface; 
 the one or more electrical contacts comprise a contact mounted by the second surface; and 
 the device comprises an electrical pathway which conductively connects the electrode with the contact mounted by the second surface. 
 
     
     
         5 . The device of  claim 4  wherein:
 the MEMS structure and the electrical pathway each comprise respective, doped portions of a common semiconductor layer between the first substrate and the second substrate; and 
 the respective, doped portions comprise a commonly-doped layer of silicon that is patterned so as to form part of the MEMS structure and part of the electrical pathway. 
 
     
     
         6 . The device of  claim 5  wherein the respective, doped portions of the common semiconductor layer comprise a silicon layer of a silicon-on-insulator wafer, heavily doped with at least one of phosphorus or antimony, and wherein the chamber is at least partially formed by a volume corresponding to a section of insulator material that has been removed from the silicon-on-insulator wafer. 
     
     
         7 . The device of  claim 5  wherein the common semiconductor layer comprises single crystal silicon. 
     
     
         8 . The device of  claim 2  wherein the chamber defines a partial vacuum relative to an ambient atmosphere external to said device. 
     
     
         9 . The device of  claim 2  wherein the first substrate and the second substrate each are composed primarily of silicon. 
     
     
         10 . The device of  claim 2  wherein at least one of the first substrate or the second substrate is bonded relative to the other via at least one of a metallic bond, an anodic bond or a glass frit bond. 
     
     
         11 . The device of  claim 2  wherein the one or more intermediate layers comprises at least one insulator layer. 
     
     
         12 . A method of manufacturing a device, the method comprising:
 providing a first substrate;   forming at least intermediate layer to lie above the first substrate, wherein forming comprises patterning a semiconductor layer to defined a microelectromechanical systems (MEMS) resonant structure, and providing a frame that encircles the MEMS resonant structure;   providing a second substrate to lie above the first substrate and the at least one intermediate layer, such that the first substrate, the second substrate and the frame cooperate to hermetically seal the MEMS resonant structure within an interior chamber of said device; and   forming one or more electrical contacts on an exterior of said device, to provide an output signal representing a resonance frequency of the MEMS resonant structure.   
     
     
         13 . An integrated circuit device comprising:
 a first substrate;   a second substrate;   in between the first substrate and the second substrate, at least intermediate layer, the at least one intermediate layer comprising a semiconductor layer patterned to defined a microelectromechanical systems (MEMS) resonant structure, the at least one intermediate layer also providing a frame that encircles the MEMS resonant structure; and   a substrate supporting at least one complementary metal oxide semiconductor (CMOS) device.