Semiconductor assembly with conductive rim and method of producing the same

Abstract

An apparatus has first and second wafers, and a conductive rim between the first and second wafers. The conductive rim electrically and mechanically connects the first and second wafers. In addition, the conductive rim and second wafer at least in part seal an area on the surface of the first wafer.

1 . A method of forming a MEMS device, the method comprising: 
 placing rim material between a first wafer and a second wafer to form an intermediate apparatus, the rim material forming a closed loop defining an area on the first wafer;    applying pressure to the intermediate apparatus; and    heating the intermediate apparatus,    after heating and applying pressure, the rim material cooperating with the first and second wafers to seal the area on the first wafer and electrically connect the first and second wafers.    
   
   
       2 . The method as defined by  claim 1  wherein the second wafer is substantially parallel with the first wafer.  
   
   
       3 . The method as defined by  claim 1  wherein the rim material cooperates with the first and second wafers by integrating with the first and second wafers to form a composite material comprising the rim material.  
   
   
       4 . The method as defined by  claim 1  wherein the rim material diffuses into the first and second wafers to form a silicide material.  
   
   
       5 . The method as defined by  claim 1  further comprising: 
 forming MEMS structure within the area on the first wafer.    
   
   
       6 . The method as defined by  claim 1  further comprising forming circuitry on the first wafer capable of applying a bias voltage to the second wafer through the rim material.  
   
   
       7 . A MEMS device formed by the method defined by  claim 1 .  
   
   
       8 . The method as defined by  claim 1  wherein rim material cooperates with the first and second wafers to hermetically seal the area on the first wafer.  
   
   
       9 . The method as defined by  claim 1  wherein the closed loop forms an irregular shape.