Apparatus for use in processing a semiconductor workpiece

Abstract

The present invention provides a chuck for receiving and supporting a semiconductor workpiece for processing. The chuck includes a body for supporting the workpiece. The body is porous or has a plurality of openings, apertures or channels. A compressible corrosion resistant member is disposed around the outer periphery of the supporting body. The chuck includes a means for evacuating air from the pores or plurality of openings, apertures or channels in the body to create a vacuum. In operation, a workpiece is placed onto the supporting body. The device side of the workpiece is preferably placed on the compressible corrosion resistant member. Upon evacuating the air (or other gas) from the pores or openings in the supporting body, a vacuum is created, drawing the workpiece toward the supporting body. A seal is created and maintained between the device side of the workpiece and the compressible corrosion resistant member. Consequently, the entire backside of the workpiece is exposed for processing while at the same time the device side of the workpiece is protected from any potentially damaging process fluids. By exposing the backside of the workpiece to a chemical etchant, semiconductor workpieces can be thinned to a desired thickness.

1 . A chuck for supporting a semiconductor workpiece having a back side and a device side, the chuck comprising: 
 a porous body for supporting the device side of the workpiece, the porous body having a compressible member attached at an outer periphery thereof;    means for evacuating air from the porous body to create a vacuum, the vacuum maintaining the workpiece adjacent to porous body and forming a seal between the compressible member and the workpiece.    
   
   
       2 . The chuck of  claim 1 , wherein the porous body comprises a material selected from the group consisting of polyethylene, polypropylene, polytetrafluoroethylene, and ceramic.  
   
   
       3 . The chuck of  claim 1 , wherein the compressible member comprises an elastomeric material selected from the group consisting of fluoroelastomers, perfluoroelastomers, silicone, perfluorinated hydrocarbons, chloroprene, ethylene propylene diene terpolymer, nitrile rubber, copolymers of tetrafluoroethylene and propylene, epichlorohydrin copolymer, and blends thereof.  
   
   
       4 . The chuck of  claim 1 , wherein the means for evacuating air from the porous body comprises a poppet valve located in a cavity in a bottom side of the porous body.  
   
   
       5 . The chuck of  claim 1 , wherein the means for evacuating air from the porous body comprises a diaphragm and compression assembly connected to a bottom side of the porous body.  
   
   
       6 . The chuck of  claim 1 , wherein the means for evacuating air from the porous body comprises a pump.  
   
   
       7 . The chuck of  claim 1 , further comprising a retainer connected to the porous body.  
   
   
       8 . The chuck of  claim 7 , wherein the retainer engages the compressible member.  
   
   
       9 . The chuck of  claim 7 , wherein the retainer wraps around the periphery of the chuck.  
   
   
       10 . The chuck of  claim 7 , wherein the retainer comprises a thermoplastic polymer.  
   
   
       11 . The chuck of  claim 10 , wherein the thermoplastic polymer is a fluoropolymer.  
   
   
       12 . The chuck of  claim 1 , wherein the compressible member includes a shoulder for receiving the periphery of the workpiece.  
   
   
       13 . A chuck for supporting a semiconductor workpiece, the chuck comprising: 
 a body for supporting the workpiece;    a plurality of openings extending through body;    a retainer connected to an outer edge of the body, the retainer having a compressible member attached thereto;    means for evacuating air from the openings in the body to create a vacuum, the vacuum maintaining the workpiece against the body and forming a seal between the compressible member in the retaining ring and the workpiece.    
   
   
       14 . The chuck of  claim 13 , wherein the body has a semiconductor workpiece support surface having a step formed therein to center the semiconductor workpiece on the workpiece support surface.  
   
   
       15 . The chuck of  claim 13 , wherein the workpiece has a back side and a device side and the body supports the entire device side of the workpiece.  
   
   
       16 . The chuck of  claim 13 , wherein the compressible member is comprised of a corrosion resistant material.  
   
   
       17 . The chuck of  claim 13 , wherein the retainer comprises an engagement member and the body comprises a recess configured to accept the engagement member and engage the retainer to the body.  
   
   
       18 . The chuck of  claim 13 , wherein the body comprises an engagement member and the retainer comprises a recess configured to accept the engagement member and engage the retainer to the body.  
   
   
       19 . A chuck for supporting a semiconductor workpiece having a back side and a device side, the chuck comprising: 
 a body for supporting the workpiece;    a plurality of openings extending through the body;    a compressible member attached to the body;    means for evacuating air from the openings in the body to create a vacuum, the vacuum maintaining the workpiece against the body and forming a seal between the compressible member and the workpiece.    
   
   
       20 . A chuck for supporting a semiconductor workpiece having a back side and a device side, the chuck comprising: 
 an upper body removeably connected to a lower body,    a cavity formed between the upper and lower bodies;    a channel formed in a surface of the upper body, the channel being in fluid communication with the cavity;    a compressible member attached to the upper body; and    means for evacuating air from the cavity and the channel in the surface of the upper body to create a vacuum, the vacuum maintaining the workpiece adjacent the surface of the upper body and forming a seal between the compressible member and the workpiece.    
   
   
       21 . The chuck of  claim 20 , further comprising a second compressible member positioned between the upper body and the lower body.  
   
   
       22 . The chuck of  claim 20 , wherein a plurality of cavities is formed between the upper and lower bodies.  
   
   
       23 . The chuck of  claim 20 , further comprising a pin for connecting the upper body and the lower body.  
   
   
       24 . The chuck of  claim 20 , wherein the seal is formed between the compressible member and the device side of the workpiece.  
   
   
       25 . The chuck of  claim 20 , wherein the upper body and the lower body are formed from a corrosion resistant thermoplastic polymer.  
   
   
       26 . The chuck of  claim 25 , wherein the corrosion resistant thermoplastic polymer is polyvinylidene fluoride.  
   
   
       27 . The chuck of  claim 25 , wherein the corrosion resistant thermoplastic polymer is polytetrafluoroethylene.