Semiconductor Wafer Chuck-Closing Force Gauge
Original Publication Date: 1983-Dec-01
Included in the Prior Art Database: 2005-Feb-07
An apparatus for accurately measuring the closing force for a wafer semiconductor centering chuck is disclosed. The closing force for centering a chuck on a photolithographic exposure machine should be maintained within the prescribed limits for the machine. If the force is too low, a wafer will not register properly on the wafer pedestal and pattern centrality will be affected. If the force is too high, there is a possibility of chipping or otherwise damaging the wafer. This disclosure describes a gauge for measuring the closing force of a chuck which is convenient to use, easy to adjust and which can measure the chuck closing force accurately. The gauge shown in Figs. 1 and 2, includes a thin metal disc 1 which is notched at approximately the same diameter as the wafer.