A system for and method of controlling the temperature of a flat workpiece
such as a semiconductor wafer are disclosed. The workpiece is mounted on a
workpiece chuck which is mounted over a base between the chuck and a host
machine such as a wafer prober used to test integrated circuits on a
wafer. The chuck includes an upper portion on which the workpiece is
mounted. The temperature of the upper portion of the chuck is controlled
to control the temperature of the workpiece. The temperature of the base
is controlled to reduce the amount of heat flow between the chuck and the
host machine. A power and control system includes a switching power supply
which provides power to system components including heaters in the chuck
used to heat the workpiece. A series of filters removes electrical noise
generated by the switching power supply such that low-noise operation is
realized.
