Low particulate slit valve system and method for controlling same

A method for controlling a closure pressure applied to a closure covering an aperture in a barrier, said closure having a face provided with an O-ring sealing member adapted to surround said aperture, said method comprising:

• measuring a first fluid pressure on a first side of said barrier;
• measuring a second fluid pressure on a second side of said barrier;
• and
• setting a separation between said closure face and a barrier seat portion surrounding said aperture which is related to the pressure differential between said first fluid pressure and said second fluid pressure.

A variable closure pressure slit valve system for use in semiconductor processing chamber comprising:

• barrier means provided with an aperture;
• seat means surrounding said aperture;
• closure means movable toward and away from said seat means;
• means for determining a first fluid pressure on a first side of said barrier means and for determining a second fluid pressure on a second side of said barrier means;
• actuator means for selectively moving said closure means toward and away from said seat means;
• and
• control means responsive to said first fluid pressure and said second fluid pressure and operative to develop discrete actuator control signals for controlling said actuator means and causing it to apply a closure force to said closure means which is related in a predetermined manner to the pressure differential between said first fluid pressure and said second fluid pressure.