Chemical mechanical polishing pad

Abstract

The present disclosure relates to a radiance decomposable CMP pad, and an associated method to refresh the CMP pad. In some embodiments, the CMP pad has a polymer layer and some macro pores disposed therein. A monomer of the polymer layer has a photoactive compound unit.

What is claimed is: 
     
         1 . A chemical mechanical polishing (CMP) pad comprising a polymer layer and macro pores disposed therein, wherein a monomer of the polymer layer comprises a photoactive compound (PAC) unit. 
     
     
         2 . The CMP pad of  claim 1 , wherein the polymer layer is decomposable through exposure to a radiance source. 
     
     
         3 . The CMP pad of  claim 2 , wherein the radiance source is an ultraviolet (UV) source. 
     
     
         4 . The CMP pad of  claim 1 , wherein the PAC unit comprises carboxylic of sulfonic acid with aromatic ring. 
     
     
         5 . The CMP pad of  claim 4 , wherein the PAC unit comprises 9-anthracene carboxylic acid or 1,2-naphthoquinonediazide-5-sulfonic acid. 
     
     
         6 . The CMP pad of  claim 1 , wherein the polymer layer comprises polyurethane. 
     
     
         7 . The CMP pad of  claim 1 , wherein the polymer layer comprises a polyol unit (Ω) and a diisocyanate unit (Σ) wherein a PAC unit is bonded to the polyol unit or the diisocyanate. 
     
     
         8 . The CMP pad of  claim 1 , wherein a polymer chain of the polymer layer comprises a structure of: 
       
         
           
           
               
               
           
         
         wherein x and y are positive integers, PAC 1  and PAC 2  are same or different units. 
       
     
     
         9 . The CMP pad of  claim 1 , wherein the polymer layer comprises polyol units (Ω), diisocyanate units (Σ) and PAC units in order of:
   (Σ) z −(Ω) x −(PAC) y  
 
   or (Σ) z −(PAC) y −(Ω) x  
 
 wherein x, y, z and n are integers. 
 
     
     
         10 . The CMP pad of  claim 1 , wherein the polymer layer comprises a copolymer. 
     
     
         11 . A chemical mechanical polishing (CMP) system, comprising:
 a rotatable wafer carrier to hold a wafer face down to be processed;   a CMP pad disposed uniformly on a rotatable polishing platen comprising a polymer layer; and   a CMP dispenser to dispense a slurry between the CMP pad and the wafer;   wherein a monomer of the polymer layer comprises a photoactive compound (PAC) unit.   
     
     
         12 . The CMP system of  claim 11  wherein the system is evidenced by an absence of a pad conditioning disk. 
     
     
         13 . The CMP system of  claim 11 , wherein a plurality of macro pores are disposed in the polymer layer. 
     
     
         14 . The CMP system of  claim 11 , further comprising a radiance source disposed above the CMP pad. 
     
     
         15 . The CMP system of  claim 14 , wherein the radiance source is an ultraviolet source. 
     
     
         16 . The CMP system of  claim 15 , wherein the ultraviolet source has a wavelength range from approximately 100 nm to approximately 380 nm. 
     
     
         17 . The CMP system of  claim 15 , wherein the ultraviolet source has an energy range from approximately 10 mJ/cm 2  to approximately 100 mJ/cm 2 . 
     
     
         18 . A method of chemical mechanical polishing (CMP), the method comprising:
 placing a wafer face down on a CMP pad;   applying a slurry between the wafer and the CMP pad;   planarizing the wafer by applying a pressure between the wafer and the CMP pad; wherein a residue is formed on the CMP pad during the planarization;   irradiating the CMP pad by a radiance source, wherein a top portion of the CMP pad is decomposed uniformly and removed together with the residue; and   cleaning the CMP pad by applying an aqueous solution.   
     
     
         19 . The method according to  claim 18 , wherein the CMP pad is cleaned by applying high pressure deionized water. 
     
     
         20 . The method according to  claim 18 , wherein the radiance source is ultraviolet source and having an irradiation time in a range of from approximately 5 seconds to approximately 40 seconds for an irradiating cycle.