Hermetic pacakging and method of manufacture and use therefore

Abstract

An embodiment of the present invention provides a method of manufacturing hermetic packaging for devices on a substrate wafer, comprising forming a plurality of adhesive rings on a cap wafer or the substrate wafer, bonding the cap wafer to the substrate wafer with an adhesive layer, forming trenches in the cap wafer and the adhesive rings along outer rim of the adhesive rings, and covering sidewall of the trenches by at least one deposited film to provide a diffusion barrier to moisture or gas.

1 . (canceled) 
   
   
       2 . A method of manufacturing hermetic packaging for MEMS devices on a substrate wafer before being diced into individual chips, comprising:
 forming separate adhesive rings on a top wafer with a gap between each other;   bonding said top wafer to said substrate wafer with said adhesive rings to form a bonded wafer;   Etching, sawing, or cutting through said top wafer along the edges of said gaps, but not through said adhesive rings, on both sides of said gap with a pattern, thereby exposing said gaps and outer rims of said adhesive rings to the open air, and forming a matrix of trenches on said bonded wafer, wherein the said trenches are centered at the middle of said gaps and have a width substantially larger than said gaps, to form a plurality of islands of cavity enclosures having said adhesive rings as sidewalls, said top wafer as cap; and said substrate as bottom;   depositing and patterning a diffusion barrier on the outer surface of said sidewalls.   
   
   
       3 . The method of  claim 2 , further comprises a stop of etching and patterning said diffusion barrier. 
   
   
       4 . The method of  claim 2 , wherein said diffusion barrier comprises a metal or a ceramic layer. 
   
   
       5 . The method of  claim 2 , wherein said trenches are formed by cutting with a dicing saw. 
   
   
       6 . The method of  claim 2 , further comprising a step of forming metal or dielectric pillars on said top wafer or on said substrate wafer prior to said bonding said top wafer to said substrate wafer. 
   
   
       7 . The method of  claim 2 , further comprising forming via holes through said cap wafer and said adhesive rings underneath, and forming interconnect through said via hole. 
   
   
       8 . The method of  claim 2 , wherein said diffusion barrier further comprises a getter. 
   
   
       9 . The method of  claim 2 , further comprising:
 (a) Depositing a structural layer on said sidewall;   (b) forming etch-access holes on said structural layer;   (c) removing part or all of said adhesive rings through said etch-access holes;   
   
   
       10 - 20 . (canceled) 
   
   
       21 . The method of  claim 9 , further comprising a step of sealing said etch-access holes with said diffusion barrier.