Method and apparatus for polishing a substrate

Abstract

A subtract such as a semiconductor wafer, a glass substrate, or a liquid crystal display is polished to a flat mirror finish, and then is cleaned to a high degree of cleanliness. A polishing section having at least one polishing unit performs primary polishing and secondary polishing of the substrate by pressing the substrate against a polishing surface. A cleaning section cleans the substrate which has been polished to remove particles attached to the substrate by a scrubbing cleaning. Metal ions are removed from the substrate by supplying an etching liquid.

What is claimed is:  
     
         1 . A polishing apparatus for polishing and then cleaning a substrate, said apparatus comprising: 
 a polishing section to polish a substrate by pressing the substrate against a polishing surface;    at least two first cleaning units to clean the substrate that has been polished, each of said at least two first cleaning units being operable to perform a first cleaning operation; and    a common second cleaning unit to clean substrates that have been cleaned by any of said at least two first cleaning units.    
     
     
         2 . The apparatus according to  claim 1 , wherein said at least two first cleaning units are operable to perform the same cleaning function.  
     
     
         3 . The apparatus according to  claim 1 , wherein each of said at least two first cleaning units is operable to clean one substrate at a time.  
     
     
         4 . The apparatus according to  claim 1 , further comprising a drying unit to dry the substrate after the substrate is cleaned by said common second cleaning unit.  
     
     
         5 . The apparatus according to  claim 1 , wherein one of said cleaning units is operable to supply an etching liquid to the substrate.  
     
     
         6 . The apparatus according to  claim 1 , wherein each of said at least two first cleaning units has a processing time that is longer than a processing time of said common second cleaning unit.  
     
     
         7 . The apparatus according to  claim 1 , wherein one of said cleaning units is to use ionic water, ozone water, or hydrogen water as a cleaning liquid.  
     
     
         8 . The apparatus according to  claim 1 , wherein said at least two first cleaning units are arranged in parallel.  
     
     
         9 . The apparatus according to  claim 1 , further comprising a conveyor to deliver a substrate from either one of said at least two first cleaning units to said common second cleaning unit.  
     
     
         10 . The apparatus according to  claim 1 , further comprising a conveyor to deliver a substrate from said polishing section to either one of said at least two first cleaning units.