Abstract: A slit assembly for use in a charged particle beam system wherein a charged particle beam is directed along a beam path. The slit assembly may be a mass resolving slit assembly for an ion implanter. The slit assembly includes first and second cylinders spaced apart from each other. Opposing surfaces of the first and second cylinders adjacent to the beam path define a slit for passing the charged particle beam. The first and second cylinders have first and second central axes, respectively. The slit assembly further includes a drive system for rotating the first cylinder about the first central axis and for rotating the second cylinder about the second central axis. The slit assembly provides low contamination and a long operating life. The slit assembly may include a system for adjusting the width of the slit. The slit assembly may further include a cooling system for controlling the temperatures of the first and second cylinders.

Abstract: Apparatus for providing thermal transfer between a semiconductor wafer and a heat sink or source in a vacuum processing chamber includes a platen against which the wafer is sealed to define a thermal transfer region therebetween. The platen includes a passage for gas flow between the chamber and the thermal transfer region and a conduit for circulation of a cooling fluid. The platen further includes a fluid-actuated valve responsive to the pressure of the cooling fluid for closing the passage. When the pressure in the chamber reaches a predetermined value, the cooling fluid is turned on and closes the valve. Gas at the predetermined pressure, typically in the range of 0.5 to 100 Torr, is trapped in the thermal transfer region and conducts thermal energy. In a preferred embodiment, a plurality of platens are positioned on a rotating disc in an ion implantation system.