Apparatus and methods for controlling process chamber pressure

摘要

The present invention provides an apparatus and methods for controlling gas pressure within a semiconductor process chamber. The apparatus comprises a throttle valve 32 positioned downstream of the process chamber outlet for controlling gas flow therethrough. The throttle valve includes a valve body 41 having a through-hole and a plug 44 movably disposed within the valve body for controlling gas flow through the through-hole. The throttle valve incorporates an abrasive element 86 disposed within the valve body in abrading contact with an exposed surface 89 of the plug. The abrasive element effectively removes gas deposited onto the exposed surface of the valve plug during operation of the throttle valve. In another aspect of the invention, the valve body comprises one or more heating elements 77, 78 thermally coupled to the exposed surface of the valve plug for conductively transferring heat to the exposed surface of the valve plug, thereby inhibiting solidification of process gases that may have deposited on this surface.