Method and apparatus for monitoring chemical mechanical polishing process

A method of monitoring a chemical mechanical polishing (CMP) apparatus, wherein the CMP apparatus comprises an arm configured to swing a polishing component, the method comprising:

• performing a CMP process;
• learning a plurality of positions of the polishing component during a normal swing motion of the polish component by an optical acceptor and a processing unit to determine an expected velocity of the normal swing motion of the polish component;
• analyzing a real velocity of the swing motion of the polishing component by the optical acceptor and the processing unit during the CMP process;
• inspecting whether an abnormal event occurs based on the analyzed real velocity and the expected velocity of the swing motion of the polishing component by the processing unit during the CMP process;
• and
• determining whether to send an alarm and stop the CMP process based on the inspecting result.

A chemical mechanical polishing (CMP) apparatus, comprising:

• a polishing pad having a polishing surface;
• a wafer carrier configured to position a surface of a wafer in contact with the polishing surface during polishing;
• a slurry supply for dispensing slurry to the polish pad;
• a conditioner having a conditioning disk in frictional engagement with the polishing surface during a CMP process;
• an optical acceptor configured to acquire an image of the CMP apparatus;
• and
• a processing unit configured to inspect whether an abnormal event occurs from the images acquired by the optical acceptor.