System, control method and apparatus for chemical mechanical polishing

Abstract

Disclosed are a chemical mechanical polishing apparatus, a control method for the chemical mechanical polishing apparatus and a chemical mechanical polishing system. In one embodiment, the chemical mechanical polishing apparatus includes a polishing pad, a sensor, a polishing head and a conditioner. The sensor is configured to obtain surface roughness of the polishing pad. The polishing head is located above the polishing pad and configured to polish a wafer which is push against the polishing pad. The conditioner is located on the polishing pad and configured to recondition the polishing pad, wherein the conditioner is operated according to at least one polishing condition, and the polishing condition is tuned according to the surface roughness of the polishing pad.

1 . A chemical mechanical polishing apparatus, comprising:
 a polishing pad;   a sensor configured to obtain surface roughness of the polishing pad;   a polishing head located above the polishing pad and configured to polish a wafer which is push against the polishing pad; and   a conditioner located on the polishing pad and configured to recondition the polishing pad, wherein the conditioner is operated according to at least one polishing condition, and the polishing condition is tuned according to the surface roughness of the polishing pad.   
     
     
         2 . The chemical mechanical polishing apparatus according to  claim 1 , wherein the sensor is configured to capture images of the polishing pad to obtain surface roughness of the polishing pad. 
     
     
         3 . The chemical mechanical polishing apparatus according to  claim 2 , wherein the sensor comprises confocal microscopy or a three-dimensional image sensor. 
     
     
         4 . The chemical mechanical polishing apparatus according to  claim 1 , wherein a field of view of the sensor is smaller than an area of the polishing pad, and
 wherein the chemical mechanical polishing apparatus further comprises:   a robotic arm configured to move the sensor between a center and an edge of the polishing pad so that the sensor is able to capture images correspond to regions between the center and the edge of the polishing pad.   
     
     
         5 . The chemical mechanical polishing apparatus according to  claim 4 , wherein the robotic arm is further configured to move the conditioner between the center and the edge of the polishing pad so that the conditioner is able to polish the polishing pad from the center to the edge of the polishing pad. 
     
     
         6 . The chemical mechanical polishing apparatus according to  claim 1 , wherein the at least one polishing condition comprises at least one of a rotational speed of the conditioner, a downward force of the conditioner that pushes the wafer against the polishing pad and a polishing time of the conditioner. 
     
     
         7 . A control method for chemical mechanical polishing apparatus having a polishing pad, a sensor, a polishing head and a conditioner, the control method comprising:
 capturing, by the sensor, images of the polishing pad to obtain surface roughness of the polishing pad;   tuning at least one polishing condition according to the surface roughness of the polishing pad;   polishing a wafer which is push against the polishing pad by the polishing head; and   reconditioning, by the conditioner, the polishing pad according to the at least one polishing condition.   
     
     
         8 . The control method according to  claim 7 , wherein the sensor comprises confocal microscopy or a three-dimensional image sensor. 
     
     
         9 . The control method according to  claim 7 , wherein a field of view of the sensor is smaller than an area of the polishing pad, and wherein capturing the images of the polishing pad comprises:
 moving the sensor between a center and an edge of the polishing pad so that the sensor is able to capture images correspond to regions between the center and the edge of the polishing pad.   
     
     
         10 . The control method according to  claim 9 , wherein reconditioning the polishing pad comprises:
 moving the conditioner between the center and the edge of the polishing pad so that the conditioner is able to polish the polishing pad from the center to the edge of the polishing pad.   
     
     
         11 . The control method according to  claim 10 , wherein the sensor and the conditioner are moved synchronously. 
     
     
         12 . The control method according to  claim 7 , wherein the at least one polishing condition comprises at least one of a rotational speed of the conditioner, a downward force of the conditioner that pushes the wafer against the polishing pad and a polishing time of the conditioner. 
     
     
         13 . The control method according to  claim 7 , wherein the step of reconditioning the polishing pad is performed prior to the step of polishing the wafer. 
     
     
         14 . The control method according to  claim 13 , wherein the step of reconditioning the polishing pad is performed again after the step of polishing the wafer. 
     
     
         15 . The control method according to  claim 14 , wherein the step of reconditioning the polishing pad is performed again synchronously with the step of polishing the wafer. 
     
     
         16 . The control method according to  claim 15 , wherein the step of reconditioning the polishing pad is performed for the third time after the step of polishing the wafer. 
     
     
         17 . The control method according to  claim 7 , wherein the step of reconditioning the polishing pad is performed synchronously with the step of polishing the wafer. 
     
     
         18 . The control method according to  claim 17 , wherein the step of reconditioning the polishing pad is performed again after the step of polishing the wafer. 
     
     
         19 . A chemical mechanical polishing system, comprising:
 a chemical mechanical polishing apparatus, comprising:
 a polishing pad; 
 a sensor configured to obtain surface roughness of the polishing pad; 
 a polishing head located above the polishing pad and configured to polish a wafer which is push against the polishing pad; and 
 a conditioner located on the polishing pad and configured to recondition the polishing pad; and 
   a controller coupled to the chemical mechanical polishing apparatus, and is configured to tune at least one polishing condition according to the surface roughness of the polishing pad and control the conditioner according to the at least one polishing condition.   
     
     
         20 . The chemical mechanical polishing system according to  claim 19 , wherein the sensor comprises confocal microscopy or a three-dimensional image sensor.