Mems device having conductive microstructures laterally surrounded by oxide material

Abstract

A MEMS device includes a first substrate structure and a second substrate structure. The first substrate structure has a conductive microstructure and an oxide material surrounding lateral side of the conductive microstructure. A thickness of the conductive microstructure and a thickness of the oxide material are approximately equivalent. The second substrate structure has an active region of the MEMS device, and the second substrate structure is coupled in spaced apart relationship with the first substrate structure to produce a cavity between the structures. The active region of the MEMS device is suspended above the cavity and the conductive microstructure underlies the cavity. The conductive microstructure is formed from a polysilicon structure layer and a local oxidation of silicon process is implemented to thermally grow the oxide material using the polysilicon of the structural layer. The second substrate structure may be coupled to the first substrate structure by fusion bonding.

1 - 20 . (canceled) 
     
     
         21 . A microelectromechanical systems (MEMS) device comprising:
 a first substrate structure having a conductive microstructure and an oxide material surrounding lateral sides of said conductive microstructure; and   a second substrate structure having an active region of said MEMS device formed therein, wherein said second substrate structure is coupled to said first substrate structure in spaced apart relationship with said first substrate structure to produce a cavity between said first and second substrate structures, said active region of said MEMS device being suspended above said cavity and said conductive microstructure underlying said cavity.   
     
     
         22 . The MEMS device of  claim 21  wherein said conductive microstructure has a first thickness and said oxide material has a second thickness that is approximately equivalent to said first thickness. 
     
     
         23 . The MEMS device of  claim 21  wherein a first surface of said conductive microstructure is approximately coplanar with a second surface of said oxide material. 
     
     
         24 . The MEMS device of  claim 23  wherein said first surface of said conductive microstructure is exposed from said oxide material. 
     
     
         25 . The MEMS device of  claim 21  wherein said conductive microstructure is formed from a polysilicon structural layer and a local oxidation of silicon process is implemented to thermally grow said oxide material using said polysilicon structural layer. 
     
     
         26 . The MEMS device of  claim 21  wherein said conductive microstructure is a first conductive microstructure, and said MEMS device further comprises a second conductive microstructure adjacent to said first conductive microstructure, said oxide material being located between said first and second conductive microstructures to provide electrical isolation between said first and second conductive microstructures. 
     
     
         27 . The MEMS device of  claim 21  wherein said first substrate structure comprises a first substrate, said conductive microstructure and said oxide material are formed on said first substrate, and said conductive microstructure and said oxide material are interposed between said first substrate and said second substrate structure. 
     
     
         28 . The MEMS device of  claim 21  wherein said second substrate structure is coupled to said first substrate structure by fusion bonding. 
     
     
         29 . The MEMS device of  claim 21  further comprising spacer elements interposed between said first and second substrate structures. 
     
     
         30 . The MEMS device of  claim 29  wherein said spacer elements are formed on said first substrate structure from said oxide material. 
     
     
         31 . The MEMS device of  claim 29  wherein said spacer elements are formed from said oxide material and said MEMS device further comprises an anchor structure extending through said second substrate structure and through one of said spacer elements formed from said oxide material. 
     
     
         32 . The MEMS device of  claim 21  further comprising a contact extending through said second substrate structure and in electrical contact with said conductive microstructure. 
     
     
         33 . The MEMS device of  claim 21  further comprising a cap structure coupled to said second substrate structure such that said MEMS device is interposed between said first substrate structure and said cap structure. 
     
     
         34 . A microelectromechanical systems (MEMS) device comprising:
 a first substrate structure having a conductive microstructure and an oxide material surrounding lateral sides of said conductive microstructure, wherein said conductive microstructure has a first thickness and said oxide material has a second thickness that is approximately equivalent to said first thickness, and wherein a first surface of said conductive microstructure is approximately coplanar with a second surface of said oxide material; and   a second substrate structure having an active region of said MEMS device formed therein, wherein said second substrate structure is coupled to said first substrate structure in spaced apart relationship with said first substrate structure to produce a cavity between said first and second substrate structures, said active region of said MEMS device being suspended above said cavity and said conductive microstructure underlying said cavity.   
     
     
         35 . The MEMS device of  claim 34  wherein said first surface of said conductive microstructure is exposed from said oxide material. 
     
     
         36 . The MEMS device of  claim 34  wherein said conductive microstructure is formed from a polysilicon structural layer and a local oxidation of silicon process is implemented to thermally grow said oxide material using said polysilicon structural layer. 
     
     
         37 . The MEMS device of  claim 34  wherein said conductive microstructure is a first conductive microstructure, and said MEMS device further comprises a second conductive microstructure adjacent to said first conductive microstructure, said oxide material being located between said first and second conductive microstructures to provide electrical isolation between said first and second conductive microstructures. 
     
     
         38 . The MEMS device of  claim 34  wherein said second substrate structure is coupled to said first substrate structure by fusion bonding. 
     
     
         39 . The MEMS device of  claim 34  further comprising spacer elements formed on said first substrate structure from said oxide layer, said spacer elements being interposed between said first and second substrate structures. 
     
     
         40 . A microelectromechanical systems (MEMS) device comprising:
 a first substrate structure having a conductive microstructure and an oxide material surrounding lateral sides of said conductive microstructure, wherein said conductive microstructure has a first thickness and said oxide material has a second thickness that is approximately equivalent to said first thickness, and wherein said conductive microstructure is formed from a polysilicon structural layer and a local oxidation of silicon process is implemented to thermally grow said oxide material using said polysilicon structural layer; and   a second substrate structure having an active region of said MEMS device formed therein, wherein said second substrate structure is coupled to said first substrate structure in spaced apart relationship with said first substrate structure to produce a cavity between said first and second substrate structures, said active region of said MEMS device being suspended above said cavity and said conductive microstructure underlying said cavity.