Two step method and apparatus for polishing metal and other films in semiconductor manufacturing

Abstract

A method and apparatus for removing a metal or conductive film from over a surface of a semiconductor wafer provides a two step process carried out within a single wafer processing apparatus. A first step is a wet chemical or mechanical removal process that removes an upper portion of the film at a high removal rate and is followed by a second step of a lower removal rate, the second step being CMP, chemical mechanical polishing.

1 . A wafer processing apparatus comprising:
 a first processing chamber comprising at least one of (a) a wet chemical etching apparatus; and (b) a mechanical polishing apparatus that removes material from a semiconductor wafer by relative motion between said semiconductor wafer and a cutting member;   a second processing chamber comprising a chemical mechanical polishing (CMP) apparatus; and   a wafer transfer apparatus that transfers said semiconductor wafer from said first processing chamber to said second processing chamber.   
   
   
       2 . The wafer processing apparatus as in  claim 1 , wherein each of said first processing chamber, said second processing chamber and said wafer transfer apparatus are internally disposed within a common housing of said wafer processing apparatus. 
   
   
       3 . The method as in  claim 2 , further comprising a wafer cleaning apparatus disposed within said housing. 
   
   
       4 . The wafer processing apparatus as in  claim 1 , wherein said first processing chamber comprises each of said wet chemical etching apparatus and said mechanical polishing apparatus. 
   
   
       5 . The wafer processing apparatus as in  claim 1 , wherein said wet chemical etching apparatus comprises a rotatable chuck and an input line that directs a stream of a wet chemical etching solution to said rotatable chuck. 
   
   
       6 . The wafer processing apparatus as in  claim 1 , wherein said first processing chamber comprises said mechanical polishing apparatus and said cutting member comprises a diamond grit. 
   
   
       7 . The wafer processing apparatus as in  claim 1 , wherein said first processing chamber comprises said mechanical polishing apparatus, said cutting member comprises at least one of a wheel, a blade and a tooth, and said mechanical polishing apparatus includes a chuck for retaining said semiconductor wafer, thereon. 
   
   
       8 . The wafer processing apparatus as in  claim 1 , wherein said first processing chamber is capable of removing a first metal from said semiconductor wafer at a removal rate that is about 2-10 times faster than a removal rate of said first metal in said second processing chamber 
   
   
       9 . A wafer processing apparatus comprising:
 a first processing chamber comprising a wet chemical etching apparatus;   a second processing chamber comprising a mechanical polishing apparatus that removes material from a semiconductor wafer seated on a chuck therein by relative motion between said chuck and a cutting member;   a third processing chamber comprising a chemical mechanical polishing (CMP) apparatus; and   a wafer transfer apparatus that transfers said semiconductor wafer from said first processing chamber to said third processing chamber and from said second processing chamber to said third processing chamber,   wherein said first, second and third processing chambers and said wafer transfer apparatus are each internally disposed within a common housing of said wafer processing apparatus.   
   
   
       10 . A method for processing a semiconductor wafer within a single apparatus comprising:
 providing a semiconductor wafer with a bulk material layer formed over a surface thereof;   removing an upper portion of said bulk material layer from said semiconductor wafer using wet chemical etching or mechanical cutting in a first processing chamber of said apparatus; and   thereafter, polishing in a second processing chamber of said apparatus thereby removing a remaining portion of said bulk material layer and exposing said surface, said polishing comprising chemical mechanical polishing (CMP).   
   
   
       11 . The method as in  claim 10 , wherein each of said first and second processing chambers are disposed within a common housing and further comprising internally transferring said semiconductor wafer from said first process chamber to said second process chamber within said common housing. 
   
   
       12 . The method as in  claim 10 , wherein said bulk material layer comprises metal and said removing an upper portion comprises a removal rate within the range of about 3-4 um/min. 
   
   
       13 . The method as in  claim 10 , wherein said material comprises metal and said removing an upper portion comprises said wet chemical etching using a mixture of deionized water, H 3 PO 4  and H 2 O 2 . 
   
   
       14 . The method as in  claim 13 , wherein said deionized water, H 3 PO 4  and H 2 O 2  are present in about a 20:1:1 ratio. 
   
   
       15 . The method as in  claim 10 , wherein said removing an upper portion comprises said mechanical cutting and includes using a diamond grit cutting surface that rotates relative said semiconductor wafer. 
   
   
       16 . The method as in  claim 10 , wherein said bulk material layer comprises a copper layer having a thickness of about 9 microns and wherein said removing an upper portion includes removing about 6-7 microns of said copper layer. 
   
   
       17 . The method as in  claim 10 , wherein said bulk material layer comprises a bulk metal layer, said bulk metal layer further filling openings that extend downward from said surface and wherein said polishing further comprises producing metal interconnect structures within said openings and having respective top surfaces being essentially coplanar with said surface. 
   
   
       18 . The method as in  claim 10 , wherein said bulk material layer comprises a bulk metal layer and said removing an upper portion includes a first removal rate and said polishing comprises a second removal rate, said first removal rate being about 2-10 times greater than said second removal rate. 
   
   
       19 . The method as in  claim 18 , wherein said bulk metal layer comprises copper and said first removal rate is about 3-4 micros/minute.