Cmp method and system with nanobubble cleaning

Abstract

A chemical mechanical planarization (CMP) system utilizes a high-pressure rinsing fluid with nanobubbles to assist in conditioning of a CMP pad. The CMP system generates nanobubbles in the rinsing fluid prior to dispensing the rinsing fluid onto the CMP pad or while the rinsing fluid is on the CMP pad. The CMP system includes a pad dresser that dresses or conditions the CMP pad while the rinsing fluid and the nanobubbles are present.

What is claimed is: 
     
         1 . A method, comprising:
 rotating a chemical mechanical planarization (CMP) pad positioned on a platen;   supplying a rinsing fluid onto the CMP pad while the CMP pad rotates;   generating nanobubbles in the rinsing fluid with ultrasonic waves; and   dressing the CMP pad with a CMP pad dresser while the rinsing fluid and the nanobubbles are present.   
     
     
         2 . The method of  claim 1 , comprising:
 performing a CMP process on a wafer with the CMP pad after dressing the CMP pad; and   supplying, with a slurry arm, a slurry onto the CMP pad while performing the CMP process on the wafer.   
     
     
         3 . The method of  claim 2 , comprising supplying the rinsing fluid onto the CMP pad with the slurry arm. 
     
     
         4 . The method of  claim 1 , wherein dressing the CMP pad includes sweeping the CMP pad dresser across the CMP pad with a dresser arm, the method comprising supplying the rinsing fluid onto the CMP pad via one or more outlets in the dresser arm. 
     
     
         5 . The method of  claim 1 , comprising:
 generating the nanobubbles in the rinsing fluid while the rinsing fluid is in an ultrasonic tank; and   supplying the rinsing fluid with the nanobubbles onto the CMP pad from the ultrasonic tank.   
     
     
         6 . The method of  claim 1 , comprising generating the nanobubbles in the rinsing fluid while the rinsing fluid is on the CMP pad. 
     
     
         7 . The method of  claim 6 , comprising generating the nanobubbles with a rotating dresser head of the CMP pad dresser while the rinsing fluid is on the CMP pad. 
     
     
         8 . The method of  claim 7 , wherein generating the nanobubbles includes generating ultrasonic waves with an ultrasonic generator embedded in the rotating dresser head. 
     
     
         9 . The method of  claim 7 , wherein generating the nanobubbles includes generating ultrasonic waves with a plurality of ultrasonic generators embedded in the rotating dresser head. 
     
     
         10 . The method of  claim 9 , comprising selectively generating ultrasonic waves with multiple frequencies with the ultrasonic generators. 
     
     
         11 . The method of  claim 9 , comprising:
 generating ultrasonic waves of a first frequency with a first ultrasonic generator of the plurality of ultrasonic generators; and   generating ultrasonic waves of a second frequency different from the first frequency with a second ultrasonic generator of the plurality of ultrasonic generators.   
     
     
         12 . The method of  claim 1 , wherein the rinsing fluid includes water and a surfactant. 
     
     
         13 . A system, comprising:
 a chemical mechanical planarization (CMP) platen;   a CMP pad dresser head configured to dress a CMP pad on the CMP platen;   a rinsing fluid tank configured to hold a rinsing fluid;   a dispensing arm configured to dispense the rinsing fluid onto the CMP pad while the CMP pad dresser head dresses the CMP pad; and   an ultrasonic generator configured to generate nanobubbles in the rinsing fluid while the CMP pad dresser head dresses the CMP pad.   
     
     
         14 . The system of  claim 13 , comprising a slurry supply system including a slurry tank, wherein the dispensing arm is configured to supply a slurry onto the CMP pad during a CMP process and to supply the rinsing fluid onto the CMP pad while the CMP pad dresser head dresses the CMP pad. 
     
     
         15 . The system of  claim 13 , wherein the dispensing arm is coupled to the CMP dresser head and is configured to sweep the CMP dresser head across the CMP pad. 
     
     
         16 . The system of  claim 13 , wherein the ultrasonic generator is part of or is coupled to the rinsing fluid tank. 
     
     
         17 . The system of  claim 13 , wherein the ultrasonic generator is part of the CMP pad dresser head. 
     
     
         18 . A device comprising:
 a chemical mechanical planarization (CMP) dresser head including:
 a plurality of hard particles configured to dress a CMP pad during a CMP pad dressing process; and 
 an ultrasonic generator configured to generate ultrasonic waves during the CMP pad dressing process. 
   
     
     
         19 . The device of  claim 18 , comprising a dresser arm configured to sweep the CMP dresser head across the CMP pad during the CMP pad dressing process and to supply a rinsing fluid onto the CMP pad during the CMP pad dressing process. 
     
     
         20 . The device of  claim 18 , wherein the CMP dresser head includes a plurality of ultrasonic generators each configured to generate ultrasonic waves during the CMP pad dressing process.