Electrical/optical integration scheme using direct copper bonding

Abstract

An electro-optic semiconductor package and fabrication method provides enhanced performance. An integrated circuit (IC) having one or more IC contact pads is provided, where the IC contact pads are connected to an IC on the IC wafer. An intermediate wafer having one or more intermediate contact pads is provided, where the intermediate contact pads are connected to an electro-optic arrangement on the intermediate wafer. The method further provides for direct copper bonding the IC contact pads to adjacent intermediate contact pads such that an electro-optic semiconductor package results.

It is claimed that:  
     
         1 . A method of fabricating an electro-optic semiconductor package, the method comprising: 
 providing an integrated circuit (IC) wafer having one or more IC contact pads, the IC contact pads being connected to an IC on the IC wafer;    providing an intermediate wafer having one or more intermediate contact pads, the intermediate contact pads being connected to an electro-optic arrangement on the intermediate wafer; and    direct copper bonding the IC contact pads to adjacent intermediate contact pads, the electro-optic semiconductor package resulting.    
     
     
         2 . The method of  claim 1  further including: 
 cleaning the contact pads;  
 disposing the IC contact pads adjacent to the intermediate contact pads in an oxidation-resistant environment having a predetermined ambient temperature; and  
 forcing the IC contact pads into direct contact with the adjacent intermediate contact pads at a predetermined pressure, a direct copper bond resulting.  
 
     
     
         3 . The method of  claim 2  further including cleaning the contact pads in an acid bath.  
     
     
         4 . The method of  claim 2  further including disposing the IC contact pads adjacent to the intermediate contact pads in a nitrogen environment.  
     
     
         5 . The method of  claim 1  further including: 
 disposing a waveguide within the intermediate wafer;  
 positioning an optical coupler adjacent to the waveguide within the intermediate wafer, the coupler enabling transport of an optical signal and the intermediate contact pads enabling transport of an electrical signal; and  
 positioning an electro-optic converter between the optical coupler and one or more of the intermediate pads, the converter enabling conversion between the optical signal and the electrical signal.  
 
     
     
         6 . The method of  claim 5  further including positioning an optical detector between the optical coupler and one or more of the intermediate pads, the detector enabling conversion of the optical signal into the electrical signal.  
     
     
         7 . The method of  claim 5  further including positioning an optical emitter between the optical coupler and one or more of the intermediate pads, the emitter enabling conversion of the electrical signal into the optical signal.  
     
     
         8 . The method of  claim 5  further including extending a via through the intermediate wafer to one or more of the intermediate contact pads.  
     
     
         9 . The method of  claim 5  further including: 
 coupling a release layer to a surface of the intermediate wafer; and  
 coupling a handle to the release layer.  
 
     
     
         10 . The method of  claim 9  further including removing the release layer after direct copper bonding the IC contact pads to the intermediate contact pads.  
     
     
         11 . The method of  claim 10  further includes etching away the release layer.  
     
     
         12 . The method of  claim 5  further including enabling conversion between the optical signal and a clock signal.  
     
     
         13 . The method of  claim 5  further including enabling conversion between the optical signal and an input/output (I/O) signal.  
     
     
         14 . The method of  claim 1  further including providing a computer processor wafer having one or more IC contact pads.  
     
     
         15 . The method of  claim 1  further including providing a chip interposer as the intermediate wafer.  
     
     
         16 . The method of  claim 1  further including providing a host wafer as the intermediate wafer.  
     
     
         17 . A method of fabricating an intermediate wafer, the method comprising: 
 disposing a waveguide within the intermediate wafer;    positioning an optical coupler adjacent to the waveguide within the intermediate wafer, the coupler enabling transport of an optical signal and one or more intermediate contact pads of the intermediate wafer enabling transport of an electrical signal; and    positioning an electro-optic converter between the optical coupler and the intermediate contact pads, the converter enabling conversion between the optical signal and the electrical signal.    
     
     
         18 . The method of  claim 17  further including positioning an optical detector between the optical coupler and one or more of the intermediate pads, the detector enabling conversion of the optical signal into the electrical signal.  
     
     
         19 . The method of  claim 17  further including positioning an optical emitter between the optical coupler and one or more of the intermediate pads, the emitter enabling conversion of the electrical signal into the optical signal.  
     
     
         20 . The method of  claim 17  further including: 
 coupling a release layer to a surface of the intermediate wafer; and  
 coupling a handle to the release layer.  
 
     
     
         21 . The method of  claim 20  further including removing the release layer after direct copper bonding one or more IC contact pads to the intermediate contact pads.  
     
     
         22 . The method of  claim 21  further including etching away the release layer.  
     
     
         23 . A method of fabricating an electro-optic semiconductor package, the method comprising: 
 providing a processor wafer having one or more IC contact pads, the IC contact pads being connected to a computer processor on the processor wafer;    coupling a release layer to a surface of an intermediate wafer;    coupling a handle to the release layer;    disposing a waveguide within the intermediate wafer;    positioning an optical coupler adjacent to the waveguide within the intermediate wafer, the coupler enabling receipt of an optical signal from the waveguide;    positioning optical detector between the optical coupler and one or more intermediate contact pads, the optical detector enabling transfer of an electrical signal to the intermediate contact pads based on the optical signal;    cleaning the contact pads in an acid bath;    disposing the IC contact pads adjacent to the intermediate contact pads in an oxidation-resistant environment having a predetermined ambient temperature; and    forcing the IC contact pads into direct contact with the intermediate contact pads at a predetermined pressure, a direct copper bond resulting.    
     
     
         24 . The method of  claim 23  further including removing the release layer after direct copper bonding the IC contact pads to the intermediate contact pads.  
     
     
         25 . The method of  claim 24  further including etching away the release layer.  
     
     
         26 . An electro-optic semiconductor package comprising: 
 an integrated circuit (IC) wafer having one or more IC contact pads, the IC contact pads being connected to an IC on the IC wafer;    an intermediate wafer having one or more intermediate contact pads, the intermediate contact pads being connected to an electro-optic arrangement on the intermediate wafer; and    said contact pads forming a plurality of direct copper bonds.    
     
     
         27 . The package of  claim 26  wherein the electro-optic arrangement of the intermediate wafer includes: 
 a waveguide disposed within the intermediate wafer;  
 an optical coupler positioned adjacent to the waveguide within the intermediate wafer, the coupler enabling receipt of an optical signal from the waveguide; and  
 an optical detector positioned between the optical coupler and one or more of the intermediate contact pads, the optical detector enabling transfer of an electrical signal to the intermediate contact pads based on the optical signal.  
 
     
     
         28 . The package of  claim 27  wherein the intermediate wafer further includes a via extending through the intermediate wafer to one or more of the intermediate contact pads.  
     
     
         29 . The package of  claim 26  further including: 
 a release layer coupled to a surface of the intermediate wafer; and  
 a handle coupled to the release layer.  
 
     
     
         30 . The package of  claim 29  wherein the handle is removable by etching away the release layer.