A novel method was developed to directly measure the substrate temperature during copper chemical mechanical planarization (CMP). Using specially designed wafer carriers, substrate temperatures were obtained in real-time with an infrared camera. Results indicate that substrate temperatures are higher than pad temperatures. In addition, the substrate temperature distribution appears to be closely related to slurry flow beneath the substrate during polishing. A three-dimensional thermal model was also developed to simulate the pad and wafer temperatures. Simulations support the interpretation of the experimental data. (c) 2005 The Electrochemical Society. All rights reserved.