System for measuring the temperature of a semiconductor wafer during thermal processing

A method of monitoring the temperature of a semiconductor wafer in a thermal processing chamber during thermal treatment comprising the steps of:

• placing a semiconductor wafer in a thermal processing chamber;
• placing a shield member adjacent to said semiconductor wafer in said thermal processing chamber without contacting said semiconductor wafer, said shield member being made from a ceramic material that increases in temperature as said semiconductor wafer is heated, said shield member having a predetermined temperature relationship with said semiconductor wafer;
• exposing said semiconductor wafer to light energy for directly heating said wafer and indirectly heating said shield member in said thermal processing chamber;
• monitoring the temperature of said shield member while said semiconductor wafer is heated;
• and
• determining the temperature of said semiconductor wafer based on the temperature of said shield member according to the predetermined relationship between the shield member and the wafer.