Slit valve assembly having a spacer for maintaining a gap

Abstract

A spacer for maintaining a gap between a slit valve door and a sealing surface of a slit valve body, such as a metallic insert is described. The spacer can extend the life of a seal by limiting the line of sight exposure of the seal to corrosive gases within a wafer processing chamber, for example, and by controlling the compression percentage of the seal. The spacer may be located on an outer ambient side of the slit valve away from any corrosive gasses that may exist in the chamber. The spacer may be attached to the slit valve door partially in a depression therein, and may be integral with the seal. Further, the present invention provides improvements to a standard slit valve assembly that enhance the effectiveness of the slit valve and the spacer. These improvements include a barrier material to protect the seal, a labyrinth to reduce particle energy, a skew-plane slit valve door, and a recess with sidewalls to continue the geometry of the process chamber in order to move the collision plane away from the seal plane.

1 . A slit valve assembly comprising:
 a slit valve body having a slit valve opening and a facing surface surrounding the slit valve opening;   a slit valve door for use in a slit valve assembly moveable between open and closed positions to respectively permit and block flow through the slit valve opening, the slit valve door having a facing surface for sealing against the facing surface of the slit valve body;   an actuation device that effectuates movement of the slit valve door;   an annular seal disposed in a groove in one of the facing surfaces and interposed therebetween to effectuate the sealing; and   a spacer interposed between the facing surfaces for maintaining a minimum gap between the facing surfaces when the door is in a closed position;   wherein the facing surfaces form interiorly of the seal a labyrinth between the facing surfaces for increasing the path length of plasma particles.   
     
     
         2 . The slit valve assembly of  claim 1 , wherein the labyrinth comprises at least one groove on at least one of the facing surfaces and a mating tongue with substantially complimentary geometry to the at least one groove, wherein the mating tongue fits inside the groove when the slit valve door is in the closed position. 
     
     
         3 . The slit valve assembly of  claim 2 , wherein the mating tongue and at least one groove are not in contact with each other during operation of the slit valve assembly. 
     
     
         4 . The slit valve assembly of  claim 2 , wherein the mating tongue and the at least one groove have substantially rectangular cross-sections. 
     
     
         5 . The slit valve assembly of  claim 2 , wherein the mating tongue is removably coupled to a groove on at least one of the facing surfaces. 
     
     
         6 . The slit valve assembly of  claim 1 , wherein an area of the slit valve door opposite the slit valve opening when the slit valve door is in the closed position is recessed. 
     
     
         7 . The slit valve assembly of  claim 1 , wherein the facing surface surrounding the valve opening is a surface of a slit valve insert removably coupled to the slit valve body. 
     
     
         8 . The slit valve assembly of  claim 1 , further comprising:
 a barrier on at least one of the facing surfaces disposed between the seal and the slit valve opening at least when the slit valve door is in the closed position.   
     
     
         9 . The slit valve assembly of  claim 1 , wherein the slit valve door is moveable along an axis for opening and closing the opening of the slit valve body, the annular seal resides on a facing surface in a plane oriented non-orthogonally to the axis, and the spacer is located transaxially outward from a relatively adjacent part of the annular seal and resides in one or more planes oriented substantially perpendicular to the axis. 
     
     
         10 - 18 . (canceled) 
     
     
         19 . A slit valve door moveable by an actuation device along an axis for opening and closing an opening of a slit valve body, comprising:
 an annular seal residing on a facing surface in a plane inclined to the axis;   one or more spacers located transaxially outward from a relatively adjacent part of the annular seal and residing in one or more planes oriented substantially perpendicular to the axis, wherein the one or more spacers are configured to maintain a minimum gap between the facing surface and a corresponding sealing surface.   
     
     
         20 . The slit valve door, of  claim 19 , wherein the slit valve door is actuated using linear motion perpendicular to the flow of wafers into and out of a mating slit valve body. 
     
     
         21 . The slit valve door of  claim 19 , further comprising:
 a barrier on the facing surface disposed between the seal and a slit valve opening.   
     
     
         22 . The slit valve door of  claim 19 , wherein the facing surface forms a labyrinth with a corresponding facing surface when the slit valve door is in a closed position. 
     
     
         23 . A slit valve assembly, comprising:
 a slit valve body having a slit valve opening and a facing surface surrounding the slit valve opening;   a slit valve door moveable between open and closed positions to respectively permit and block flow through the slit valve opening, the slit valve door having a facing surface juxtaposed the facing surface of the slit valve body;   an actuation device that effectuates movement of the slit valve door;   an annular seal on at least one of the facing surfaces that seals between the facing surfaces;   a barrier on at least one of the facing surfaces and protruding therefrom, disposed between the seal and the slit valve opening at least when the slit valve door is in the closed position; and   a spacer for maintaining a minimum gap between the facing surfaces, the spacer having a thickness sufficient to prevent compression or over compression of the barrier.   
     
     
         24 . The slit valve assembly of  claim 23 , wherein the spacer has a thickness greater than or equal to the thickness of the barrier. 
     
     
         25 . The slit valve assembly of  claim 23 , wherein the facing surfaces form a labyrinth between the seal and the slit valve opening. 
     
     
         26 . The slit valve assembly of  claim 23 , wherein an area of the slit valve door opposite the slit valve opening when the slit valve door is in the closed position is recessed. 
     
     
         27 . (canceled) 
     
     
         28 . The slit valve assembly of  claim 23 , wherein the slit valve door is moveable along an axis for opening and closing the opening of the slit valve body, the annular seal resides on a facing surface in a plane oriented non-orthogonally to the axis, and the spacer is located transaxially outward from a relatively adjacent part of the annular seal and resides in one or more planes oriented substantially perpendicular to the axis. 
     
     
         29 . (canceled) 
     
     
         30 . The slit valve assembly of  claim 19 , wherein the facing surface is a multi-plane facing surface wherein the multi-plane facing surface includes a plurality of component facing surfaces substantially perpendicular to the flow through the slit valve opening, and the actuation device effectuates movement of the slit valve door along an axis of movement substantially perpendicular to the flow through the slit valve opening. 
     
     
         31 . The slit valve door, of  claim 19 , wherein the annular seal residing on a facing surface in a plane oriented obliquely to the axis.