Integrated in-line temperature measurement system for silicon wafer semiconductor manufacturing

Lithography is a major process in wafer manufacturing. With increasing wafer size and decreasing feature size, it is important to have precise control of temperature and other environmental variables. In particular, control of the spatial distribution of temperature across the wafer is crucial. In current practice, wafer temperature is not usually measured inline during the baking, chilling and developing steps in the lithography process. This paper describes the development of an inline temperature measurement system which will measure the wafer's spatial temperature distribution during these steps. Data obtained will be used to design and realize closed loop control for the desired spatial temperature uniformity.