Method for conditioning polishing pad

A method, comprising:

• performing a CMP process to a wafer using a polishing pad;
• obtaining a surface profile of a polishing pad through at least one sensor;
• based on the surface profile of the polish pad, calculating a thickness difference between a first location and a second location of a polishing pad;
• sweeping a conditioner across a surface of the polishing pad;
• and
• modifying a downforce or a sweeping speed of the conditioner that urges the conditioner against the polishing pad according to the thickness difference, wherein the CMP process and modifying the downforce or the sweeping speed of the conditioner are performed at least partially simultaneously.

A method, comprising:

• performing a CMP process to a wafer using a polishing pad;
• obtaining a surface profile of a polishing pad through a sensor;
• based on the surface profile of the polish pad, calculating a thickness difference between a first location and a second location of a polishing pad;
• sweeping a conditioner across a surface of the polishing pad by rotating the conditioner through a scan arm, wherein the sensor is fixed on the scan arm;
• and
• modifying a downforce or a sweeping speed of the conditioner that urges the conditioner against the polishing pad according to the thickness difference.