Laser release process for very thin Si-carrier build

Abstract

A laser release and glass chip removal process for a integrated circuit module avoiding carrier edge cracking is provided.

1 . An article comprising a semi-conductor carrier or device wafer, comprising: 
 a semi-conductor substrate having CMOS BEOL wiring defined thereon;    a layer of a synthetic resin release adhesive applied and cured on the said substrate, or on a glass handler wafer, or both; wherein the adhesive upon curing can withstand temperatures of at least 400° C.; and    a glass handler wafer laminated with the adhesive located between the semiconductor substrate and glass handler wafer.    
     
     
         2 . The article, according to  claim 1 , wherein the glass handler wafer has radiation transmission properties which allow adequate transmission of the selected laser wavelength to effect ablation of the adhesive.  
     
     
         3 . The article according to  claim 1  wherein the adhesive is a polyimide.  
     
     
         4 . The article according to  claim 1  wherein the adhesive is coated on either the substrate or the glass handler wafer, and another high temperature stable polymer is coated on the other wafer.  
     
     
         5 . The article according to  claim 1  wherein said carrier is a silicon-carrier wafer.  
     
     
         6 . An integrated circuit module comprising the article according to  claim 1  further comprising C4 balls deposited on the carrier wafer; wherein the article is diced to a pre-determined size; and a substrate having the article joined thereon by the C4 balls.  
     
     
         7 . The module of  claim 6  wherein the carrier wafer has a thickness that corresponds to the thickness of CMOS BEOL wiring.  
     
     
         8 . The module according to  claim 6  wherein the carrier wafer has a thickness greater than the CMOS BEOL but less than about 15 μm.  
     
     
         9 . The article of  claim 3  which further comprises an adhesion promoter between the adhesive and carrier wafer.  
     
     
         10 . The article of  claim 9  wherein the promoter comprises a silane.  
     
     
         11 . The article of  claim 9  wherein the promoter comprises aminopropyltriethoxy silane.  
     
     
         12 . A process of fabricating an integrated circuit module on a glass handle wafer; 
 obtaining a semiconductor substrate having CMOS BEOL wiring defined thereon;    obtaining a glass handler wafer; applying a layer of a synthetic adhesive on the said substrate or on the said glass handler wafer or both; and curing said adhesive, wherein the adhesive upon curing can withstand temperatures of at least 400° C.;    laminating the glass handler wafer to the semiconductor substrate with the adhesive located between the semiconductor substrate and glass handler wafer;    thinning the semiconductor-carrier wafer to the thickness of the CMOS BEOL wiring or greater than the thickness of the CMOS BEOL wiring but less than about 150 μm;    carryout out processing on the backside of the semiconductor-carrier wafer after the thinning;    depositing C4 balls on the semiconductor-carrier wafer;    then dicing the carrier wafer with the glass-handler wafer to a pre-determined carrier size;    joining the diced semiconductor carrier-laminated glass handler wafer to a substrate using the C4 balls.    
     
     
         13 . A process of fabricating an integrated circuit module which comprises subjecting the supported module fabricated according to  claim 12  to an eximer laser release process to degrade the release adhesive and separating the glass handler wafer from the module.  
     
     
         14 . The process of  claim 13  which further comprises placing the module onto a vacuum chuck of a X-Y translation stage to minimize module jitter during ablation/release; 
 wherein the edges of the carrier/adhesive/glass handler module are exposed first on tilt stage to the laser radiation; and    wherein the bulk carrier/adhesive/glass handler module is exposed to laser radiation at 0 degree tilt.    
     
     
         15 . The process according to  claim 14  which further comprises 
 placing the carrier/adhesive/glass handler module that has been exposed to laser radiation on a vacuum stage of a glass handler removal tool; applying vacuum to hold the module in place;    manually bringing down the glass handler removal vacuum head assembly into contact with the module, wherein the glass handler removal vacuum head assembly is micrometer controlled;    applying vacuum to the glass handler chips;    pulling off the glass handler chip in a controlled manner to avoid cracking of the carrier edges.    
     
     
         16 . The process according to  claim 15  which further comprises 
 treating the module after removing the handler glass chip with a soap-containing rinse for removing carbon ash; then rinsing with water; then drying; and then removing residual adhesive by plasma etching.    
     
     
         17 . The process according to  claim 16  wherein the drying is a N 2 -drying process.  
     
     
         18 . The process according to  claim 16  which further comprises cleaning after the plasma etching by a super-critical CO 2  dry cleaning process.  
     
     
         19 . The process according to  claim 13  which further comprises: 
 placing the module onto a vacuum which of a X-Y translation stage to minimize module jitter during ablation/release;    wherein the edges of the carrier/adhesive/glass handler module are exposed first on tilt state to the laser radiation;    wherein the tilt stage may vary in angle from 90 degrees to zero degrees normal to the optical axis of the laser beam;    where the bulk Si-carrier/adhesive/glass handler module is exposed to the optical axis of the laser radiation at 90 degrees.    
     
     
         20 . The process according to  claim 19  which further comprises 
 placing the carrier/adhesive/glass handler module that has been exposed to laser radiation on a vacuum stage of a glass handler removal tool; applying vacuum to hold the module in place;    manually bringing down the glass handler removal tool into contact with the module, wherein the glass handler removal tool is micrometer controlled;    applying vacuum to the glass handler chip;    pulling off the glass handler chip in a controlled manner to avoid cracking of the carrier edge.    
     
     
         21 . The process according to  claim 20  which further comprises 
 treating the module after removing the handler glass chip with a soap-containing rinse for removing carbon ash; then rinsing with water; then drying; and then removing residual adhesive by plasma etching.    
     
     
         22 . The process according to  claim 21  wherein the drying is a N 2 -drying process  
     
     
         23 . The process according to  claim 21  which further comprises cleaning after the plasma etching by a super-critical CO 2  dry cleaning process.  
     
     
         24 . The module according to  claim 6  which farther comprises an underfill comprising epoxy resin and silicon filler.