Method and apparatus for temporary bonding of ultra thin wafers

Abstract

An apparatus for temporary bonding first and second wafers includes, a first coating chamber configured to apply a first adhesive layer upon a first surface of a first wafer; a second coating chamber configured to apply a second adhesive layer upon a first surface of a second wafer; a curing chamber configured to cure the first adhesive layer of the first wafer; a bonder module comprising an upper chuck assembly and a lower chuck assembly arranged below and opposite the upper chuck assembly. The upper chuck assembly is configured to hold the first wafer so that its first surface with the cured first adhesive layer faces down. The lower chuck assembly is configured to hold the second wafer so that the second adhesive layer faces up and is opposite to the cured first adhesive layer. The lower chuck assembly is configured to move upwards and thereby to bring the second adhesive layer in contact with the cured first adhesive layer. The curing chamber is further configured to cure the second adhesive layer after it is brought in contact with the cured first adhesive layer, thereby forming a temporary bond between the first and second wafers.

1 . An apparatus for temporary bonding two wafer surfaces comprising:
 a first coating chamber configured to apply a first adhesive layer upon a first surface of a first wafer;   a second coating chamber configured to apply a second adhesive layer upon a first surface of a second wafer;   a curing chamber configured to cure the first adhesive layer of the first wafer;   a bonder module comprising an upper chuck assembly and a lower chuck assembly arranged below and opposite the upper chuck assembly;   wherein said upper chuck assembly is configured to hold said first wafer so that its first surface with the cured first adhesive layer faces down;   wherein said lower chuck assembly is configured to hold said second wafer so that said second adhesive layer faces up and is opposite to said cured first adhesive layer;   wherein said lower chuck assembly is configured to move upwards and thereby to bring said second adhesive layer in contact with said cured first adhesive layer; and   wherein said curing chamber is further configured to cure said second adhesive layer, thereby forming a temporary bond between said first and second wafers.   
     
     
         2 . The apparatus of  claim 1 , wherein said curing chamber is configured to cure said second adhesive layer by bringing a hot plate in contact with a second surface of the second wafer. 
     
     
         3 . The apparatus of  claim 1 , wherein said curing chamber is configured to cure said first and second adhesive layers via at least one of Ultraviolet (UV), thermal, pressure, catalytic, chemical or time induced curing process. 
     
     
         4 . The apparatus of  claim 1 , wherein the upper and lower chuck assemblies comprise low force upper and lower chucks, respectively, and wherein the second adhesive layer is brought in contact with said cured first adhesive layer by first evacuating the bonder module and then bringing the bonder module to atmospheric pressure via purging. 
     
     
         5 . The apparatus of  claim 1 , wherein said first adhesive layer is applied upon said first surface of the first wafer via spin coating. 
     
     
         6 . The apparatus of  claim 1 , wherein said first adhesive layer comprises a silicone elastomer. 
     
     
         7 . The apparatus of  claim 1 , wherein said curing of the first and second adhesive layers occurs at a curing temperature in the range of 80° C. to 160° C. and a curing time in the range of 1 to 15 minutes. 
     
     
         8 . The apparatus of  claim 1 , wherein said curing chamber is further configured to cure said temporary bonded first and second wafers. 
     
     
         9 . The apparatus of  claim 8 , wherein said curing of said temporary bonded first and second wafers occurs at a curing temperature in the range of 120° C. to 220° C. and a curing time in the range of 1 to 15 minutes. 
     
     
         10 . The apparatus of  claim 1 , wherein said first adhesive layer comprises a thickness of less than 110 micrometers and wherein said second adhesive layer comprises a thickness of less than 30 micrometers.