Method of producing a MEMS device

Abstract

A method of producing a MEMS device removes the bottom side of a device wafer after its movable structure is formed. To that end, the method provides the device wafer, which has an initial bottom side. Next, the method forms the movable structure on the device wafer, and then removes substantially the entire initial bottom side of the device wafer. Removal of the entire initial bottom side effectively forms a final bottom side.

1 . A method of producing a MEMS device, the method comprising:
 providing a device wafer having an initial bottom side and a top side;   forming movable structure on top of the device wafer;   coupling a cap wafer to the device wafer, the cap wafer encapsulating the moveable structure; and   removing substantially the entire initial bottom side of the device wafer after the movable structure is formed on the device wafer, removing forming a final bottom side;   after removing substantially the entire initial bottom side of the device wafer, singulating the cap wafer to form individual caps on the device wafer; and   dicing the device wafer into individual MEMS devices.   
   
   
       2 . The method as defined by  claim 1  wherein removing includes backgrinding the initial bottom side. 
   
   
       3 . The method as defined by  claim 1  wherein removing includes using a chemical to chemically etch the initial bottom side, the structure being sealed from the chemical. 
   
   
       4 . The MEMS device as defined by  claim 1  wherein removing is performed before coupling. 
   
   
       5 . A method of producing a MEMS device, the method comprising:
 providing a device wafer having an initial bottom side, a top side, a movable structure, and a cap wafer encapsulating the moveable structure;   removing substantially the entire initial bottom side of the device wafer to form a final bottom side, the operation of the movable structure being substantially unaffected by removal of substantially the entire initial bottom side of the device wafer,   after removing substantially the entire initial bottom side, singulating the cap wafer to form individual caps on the device wafer; and   dicing the device wafer into individual MEMS devices.   
   
   
       6 . The method as defined by  claim 5  wherein removing includes backgrinding the initial bottom side. 
   
   
       7 . The method as defined by  claim 5  wherein removing includes using a chemical to chemically etch the initial bottom side, the structure being sealed from the chemical. 
   
   
       8 . The MEMS device produced in accordance with the method of  claim 5 . 
   
   
       9 . A method of producing a MEMS device, the method comprising:
 providing a device wafer having an initial bottom side and movable structure;   fixing the device wafer to a protective plastic film having a clearance hole, the movable structure being sealed within the clearance hole; and   after the device wafer is fixed to the protective plastic film, removing substantially the entire initial bottom side of the device wafer to form a final bottom side, removing including at least one of backgrinding and chemically etching the initial bottom side.   
   
   
       10 . The method as defined by  claim 9  further including:
 removing the plastic film; and   coupling a cap wafer to the device wafer.   
   
   
       11 . The method as defined by  claim 10  further comprising:
 singulating the cap wafer before removing the initial bottom side.   
   
   
       12 . The method as defined by  claim 10  further comprising:
 singulating the cap wafer after removing the initial bottom side.   
   
   
       13 . The method as defined by  claim 12  further comprising:
 after singulating the cap wafer, dicing the device wafer into individual MEMS devices.   
   
   
       14 . The MEMS device produced in accordance with the method of  claim 9 .