Slurry enhancement for polishing system

Abstract

The present disclosure describes a method and an apparatus that can enhance the slurry oxidizability for a chemical mechanical polishing (CMP) process. The method can include securing a substrate onto a carrier of a polishing system. The method can further include dispensing, via a feeder of the polishing system, a first slurry towards a polishing pad of the polishing system. The method can further include forming a second slurry by enhancing an oxidizability of the first slurry, and performing a polishing process, with the second slurry, on the substrate.

What is claimed is: 
     
         1 . A method, comprising:
 securing a substrate onto a substrate carrier and against a polishing pad;   dispensing a slurry onto the polishing pad;   increasing an oxidizability of the slurry via a irradiation source, while moving the irradiation source to follow the substrate carrier; and   performing a polishing process, with the slurry, on the substrate.   
     
     
         2 . The method of  claim 1 , wherein increasing the oxidizability of the slurry comprises irradiating the slurry with an ultraviolet light. 
     
     
         3 . The method of  claim 1 , wherein increasing the oxidizability of the slurry comprises generating, via the irradiation source, a light with a wavelength from about 200 nm to about 500 nm. 
     
     
         4 . The method of  claim 1 , wherein increasing the oxidizability of the slurry comprises irradiating the slurry within a proximity of the substrate carrier. 
     
     
         5 . The method of  claim 1 , further comprising:
 detecting a polishing rate of the polishing process; and   adjusting a wavelength or a power of an irradiation of the irradiation source based on the polishing rate.   
     
     
         6 . The method of  claim 1 , wherein performing the polishing process comprises:
 before increasing the oxidizability of the slurry, performing a first polishing process using the slurry; and   after increasing the oxidizability of the slurry, performing a second polishing process using the slurry.   
     
     
         7 . The method of  claim 1 , wherein increasing the oxidizability of the slurry comprises controlling a separation between the irradiation source and the substrate carrier. 
     
     
         8 . The method of  claim 1 , wherein increasing the oxidizability of the slurry comprises determining an irradiation angle of the irradiation source with respect to the polishing pad. 
     
     
         9 . A method, comprising:
 moving a substrate on a polishing pad to perform a polishing process on the substrate;   providing a slurry towards the polishing pad;   irradiating the slurry by an irradiation source, while moving the irradiation source to follow the substrate;   detecting a polishing rate of the polishing process; and   adjusting the polishing rate based on a comparison between the polishing rate and a reference.   
     
     
         10 . The method of  claim 9 , wherein adjusting the polishing rate comprises adjusting a wavelength or a power of an irradiation of the irradiation source, wherein the irradiation enhances an oxidizability of the slurry. 
     
     
         11 . The method of  claim 8 , wherein irradiating the slurry comprises irradiating the slurry with an ultraviolet light. 
     
     
         12 . The method of  claim 8 , wherein irradiating the slurry comprises irradiating the slurry within a proximity of a substrate carrier securing the substrate against the polishing pad. 
     
     
         13 . The method of  claim 8 , wherein irradiating the slurry comprises controlling a separation between the irradiation source and the substrate from about 5 mm to about 100 mm. 
     
     
         14 . The method of  claim 8 , wherein irradiating the slurry comprises controlling an irradiation power of the irradiation source from about 0 Watts to about 500 Watts. 
     
     
         15 . An apparatus, comprising:
 a polishing pad configured to polish a substrate;   a substrate carrier configured to hold the substrate against the polishing pad;   a feeder configured to dispense a slurry towards the polishing pad; and   an irradiation source configured to:
 increase an oxidizability of the slurry; 
 move across a top surface of the polishing pad; and 
 follow the substrate carrier. 
   
     
     
         16 . The apparatus of  claim 15 , wherein the irradiation source comprises an ultraviolet (UV) light source configured to irradiate the slurry within a proximity of the substrate carrier. 
     
     
         17 . The apparatus of  claim 15 , wherein the irradiation source is further configured to follow the substrate carrier within a distance, wherein a ratio between the distance and a diameter of the polishing pad is from about 0.01 to about 0.8. 
     
     
         18 . The apparatus of  claim 15 , wherein the irradiation source is further configured to follow the substrate carrier within a separation between about 5 mm and about 100 mm. 
     
     
         19 . The apparatus of  claim 15 , further comprising a detection module configured to measure a polishing rate of the substrate. 
     
     
         20 . The apparatus of  claim 15 , wherein the irradiation source is further configured to adjust an irradiation angle with respect to the polishing pad.