Patent ID: 9267605
Filing Date: 2016-02-23
CPC Classification: F16K,H01J,H01L,Y10T

Claim Text:
1. A pressure control valve assembly of a plasma processing chamber in which semiconductor substrates are processed, comprising: a housing having an inlet, an outlet and a conduit extending between the inlet and the outlet, the inlet adapted to be connected to an interior of the plasma processing chamber and the outlet adapted to be connected to a vacuum pump which maintains the plasma processing chamber at desired pressure set points during processing of a semiconductor substrate in the chamber; a fixed slotted valve plate having a first set of parallel slots therein and immovably fixed in the conduit such that gasses withdrawn from the chamber into the conduit pass through the first set of parallel slots; a movable slotted valve plate in the conduit having a second set of parallel slots therein and movable to first and second positions with respect to the fixed slotted valve plate so as to partially block the first set of parallel slots in the first position to a greater extent than in the second position; and a drive mechanism attached to the movable slotted valve plate and operable to rapidly move the movable slotted valve plate between the first and second positions to change pressure in the chamber from a higher pressure to a lower pressure or from a lower pressure to a higher pressure; wherein the fixed and movable slotted valve plates are circular, the first and second sets of slots having uniform widths W and varying lengths, and wherein the first and second slots provide an open area of 10 to 20% through the fixed slotted valve plate and the movable valve plate when the movable valve plate is positioned in the first position and the first and second slots provide an open area of 25 to 50% through the fixed slotted valve plate and the movable valve plate when the movable valve plate is positioned in the second position.