Fabrication of stacked die and structures formed thereby

Abstract

Methods of forming a microelectronic structure are described. Those methods comprise forming a bond between a non-device side of a first die and a non-device side of a second die, wherein forming the bond between the non-device side of the first die and the non-device side of the second die does not comprise using an interfacial glue.

1 . A method of forming a microelectronic structure comprising; 
 forming a bond between a non-device side of a first individual die and a non-device side of a second individual die, wherein forming the bond between the non-device side of the first individual die and the non-device side of the second individual die does not comprise using an interfacial glue.    
     
     
         2 . The method of  claim 1  wherein forming a bond comprises forming a silicon to silicon bond comprising Van der Waal forces.  
     
     
         3 . The method of  claim 1  wherein forming a bond comprises: 
 bringing the non-device side of the first individual die and the non-device side of the second individual die in contact with each other; and    heating the non-device side of the first individual die and the non-device side of the second individual die to a temperature between about 250 to about 450 degrees Celsius.    
     
     
         4 . The method of  claim 1  wherein not using an interfacial glue comprises not using an interfacial glue selected from the group consisting of solder, organic adhesives and polymer adhesives.  
     
     
         5 . The method of  claim 1  wherein the non-device side of the first individual die and the non-device side of the second individual die are thinned prior to forming the bond.  
     
     
         6 . The method of  claim 5  wherein the non-device side of the first individual die and the non-device side of the second individual die are thinned to a thickness of about 50 microns to about 100 microns prior to forming the bond.  
     
     
         7 . The method of  claim 5  wherein the non-device side of the first individual die and the non-device side of the second individual die are thinned by at least one of polishing or grinding.  
     
     
         8 . A method of forming a microelectronic structure comprising: 
 thinning a non-device portion of a wafer, wherein the wafer comprises a plurality of die;    separating the wafer into a plurality of individual die;    bringing the non-device side of a first individual die and the non-device side of a second individual die into contact with each other; and    forming a bond between the non-device side of the first individual die and the non-device side of the second individual die without using an interfacial glue.    
     
     
         9 . The method of  claim 8  wherein forming a bond comprises heating the non-device side of the first individual die and the non-device side of the second individual die to a temperature between about 250 to about 450 degrees Celsius.  
     
     
         10 . The method of  claim 8  wherein without using an interfacial glue comprises without using an interfacial glue selected from the group consisting of solder, organic adhesives and polymer adhesives.  
     
     
         11 . The method of  claim 8  wherein separating the wafer comprises sawing the wafer.  
     
     
         12 . The method of  claim 8  further comprising attaching a first land grid array to a device side of the first individual die and a second land grid array to a device side of the second individual die.  
     
     
         13 . The method of  claim 12  wherein attaching a first land grid array to the device side of the first individual die and a second land grid array to the device side of the second individual die comprises attaching a first organic land grid array to the device side of the first individual die and a second organic land grid array to the device side of the second individual die.