Apparatus for shielding process chamber port having dual zone and optical access features

Abstract

A port in a window member provides first access to a process chamber interior for gas injection and second optical access for process analysis and measurement. Plasma-induced etching and deposition in a bore of a gas injector integral with the window member is reduced by a grounded shield surrounding an access region, and coatings reduce particle flaking from walls of a first clear optical aperture of the injector and from a second clear optical aperture of a gas and optical access fitting,. The shield surrounds the region, and is configured with couplers to hold the gas and optical access fitting to the window member for access to the injector. The couplers compress seals so that a gas bore in the fitting is sealed to a plenum of the injector, while allowing optical access into the chamber through the first clear optical aperture and the second clear optical aperture.

1 . A window for protecting an access region for access to a process chamber from an electric field generated adjacent to the process chamber window, the window comprising: 
 a window member configured with outer and chamber sides and a groove extending from the outer side into the member parallel to the axis, the groove defining a first section of the access region to be protected from the electric field, the window member being further configured with a clear optical aperture having an annular wall configured with an axial length between the outer side and the chamber side, the clear optical aperture being partly surrounded by the groove, the clear optical aperture being further configured with a diameter; and    a coating on the annular wall of the clear optical aperture, the annular wall with the coating having an inner coating diameter that is substantially the same as a value of the axial length of the clear optical aperture, the material from which the coating is fabricated being taken from the group consisting of cerium oxide, zirconium oxide, yttria-stabilized zirconia, thermally-sprayed aluminum oxide, yttrium oxide, and yttrium oxide having pores, wherein the pores are sealed with a material taken from the group consisting of methacylate ester and polymer.    
   
   
       2 . A process chamber window as recited in  claim 1 , wherein the window member is further configured from one piece of ceramic.  
   
   
       3 . A process chamber window as recited in  claim 1 , wherein the window member is further configured with an annular gas plenum and a plurality of nozzles, each of the nozzles being connected to the annular gas plenum.  
   
   
       4 . A process chamber window as recited in  claim 1 , wherein the chamber side of the window member is configured with a flat surface.  
   
   
       5 . A process chamber window as recited in  claim 3 , wherein the chamber side of the window member is configured with a projection defined by an axially-extending surface and a flat surface parallel to the chamber side, the nozzles intersecting the axially-extending surface.  
   
   
       6 . A multi-function process chamber window assembly for protecting an access region for access to a process chamber from an electric field generated adjacent to the process chamber window, for admitting at least one gas to the process chamber, and for providing optical access to the chamber, the assembly comprising: 
 a three-dimensional shield having a length extending parallel to an access region axis and being fabricated from material adapted to substantially block the electric field;    a window member configured with respect to the access region axis, the member being configured with outer and chamber sides and a groove extending from the outer side into the member, the groove extending parallel to the axis, the groove defining a first section of the access region to be protected from the electric field, the groove being configured to receive a portion of the shield to protect the first section of the access region from the electric field, the groove receiving the portion of the shield so that the shield extends out of the groove and away from the outer side so that a second section of the access region is defined within the shield, the shield protecting the second section from the electric field, the window member being further configured with a first clear optical aperture defined by a first annular wall extending co-axially with the axis and configured with an axial length between the outer side and the chamber side, the first clear optical aperture being partly surrounded by the groove, the first clear optical aperture being further configured with a diameter for clear optical access; and    a first coating on the first annular wall, the first annular wall with the coating having an inner coating diameter that is substantially the same as a value of the axial length of the first clear optical aperture, the coating protecting the first clear optical aperture from effects of the electric field so that the protection extends past the shield in the groove to the chamber side of the window member, the material from which the first coating is fabricated being taken from the group consisting of cerium oxide, zirconium oxide, yttria-stabilized zirconia, thermally-sprayed aluminum oxide, yttrium oxide, and yttrium oxide having pores, wherein the pores are sealed with a material taken from the group consisting of methacylate ester and polymer.    
   
   
       7 . An assembly as recited in  claim 6 , the assembly further comprising: 
 a multi-function fitting received within the second section of the access region defined by the shield for protection from the electric field, the fitting being configured with a second clear optical aperture having a second annular wall extending co-axially with the axis and aligned with the coated first clear optical aperture to supply gas to the first clear optical aperture and allow clear optical access to the chamber through the first and second clear optical apertures.    
   
   
       8 . An assembly as recited in  claim 7 , wherein: 
 the window member is configured with a plenum extending from the outer side into the member and with a plurality of nozzles extending from the plenum to the chamber side to supply gas to the chamber; and    the fitting is further configured with a gas supply bore extending parallel to the axis and aligned with the plenum.    
   
   
       9 . An assembly as recited in  claim 8 , the assembly further comprising a seal structure between the fitting and the window member.  
   
   
       10 . An assembly as recited in  claim 9 , wherein: 
 the shield is configured with opposite ends, each of the ends being configured with a coupler, one coupler securing the shield to the window member with the shield in the groove, the other coupler securing the fitting to the shield so that the fitting is urged toward the window member; and    the seal structure is configured so that in response to the other coupler urging the fitting toward the window member the seal structure seals to the window member so that gas flows from the gas supply bore into the plenum separately from the first and second clear optical apertures and gas flows from the second clear optical aperture into the first clear optical aperture separately from the gas supply bore and the plenum.    
   
   
       11 . An assembly as recited in  claim 7 , wherein the fitting is configured with an end, the assembly further comprising: 
 a first seal structure between the end of the fitting and the window member; and    wherein the end is configured with a seat adjacent to the seal structure and co-axial with the access region axis;    the assembly further comprising an optical window received in the seat and a second seal structure between the seat and the optical window to prevent gas from leaking past the second optical aperture while allowing optical access through the second clear optical aperture and the first clear optical aperture into the chamber.    
   
   
       12 . An assembly as recited in  claim 11 , wherein the fitting is further configured with at least one access port in the second annular wall to provide access to the optical window, the port being located on a side of the optical window that is away from the window member.  
   
   
       13 . An assembly as recited in  claim 7 , wherein the second clear optical aperture is configured so that the second annular wall is open from a first end that is adjacent to the window member to a second end spaced from the window member, the second end of the fitting being further configured with a sealing seat, the assembly further comprising: 
 the assembly further comprising an optical window received in the sealing seat and a second seal structure between the seat and the optical window to prevent gas from leaking past the second optical aperture while allowing optical access through the second clear optical aperture and the first clear optical aperture into the chamber;    the spacing of the second end from the window member enabling location of the optical window where the strength of the electric field is substantially reduced as compared to the electric field strength adjacent to the process chamber window.    
   
   
       14 . An assembly as recited in  claim 13 , the assembly further comprising: 
 a second coating on the second annular wall, the second coating extending from the first end for a distance about equal to the diameter of the second annular wall; and    a third coating on the second annular wall, the second coating extending from the second end for a distance about equal to the diameter of the second annular wall;    the second and third coatings being fabricated from the same material as the first coating.    
   
   
       15 . An assembly as recited in  claim 6 , wherein: 
 the window member is configured with an annular plenum extending from the outer side into the member and with a plurality of nozzles extending from the annular plenum to the chamber side to supply gas to the chamber;    the assembly further comprises a multi-function fitting received within the second section of the access region defined by the shield for protection from the electric field, the fitting being configured with a second clear optical aperture having a second annular wall extending co-axially with the axis and aligned with the coated first clear optical aperture to supply gas to the first clear optical aperture and allow clear optical access to the chamber through the first and second clear optical apertures, the fitting is further configured with a gas supply bore extending parallel to the axis and aligned with the annular plenum;    the shield is configured with opposite ends, each of the ends being configured with a coupler, one coupler securing the shield to the window member with the shield in the groove, the other coupler securing the fitting to the shield so that the fitting is urged toward the window member, the end configured with the one coupler being configured with a seat that is co-axial with the access region axis; and    the assembly further comprises a first seal structure between the window member and the one end of the fitting that is configured with the one coupler, the first seal structure sealing the gas supply bore to the plenum, an optical window received in the seat, a second seal structure between the seat and the optical window to prevent gas from leaking past the second optical aperture while allowing optical access through the second clear optical aperture and the first clear optical aperture into the chamber.    
   
   
       16 . An assembly as recited in  claim 15 , wherein: 
 the fitting is further configured with a second gas supply bore extending relative to the axis to supply gas to the first clear optical aperture;    the first seal structure seals the second gas supply bore to the first clear optical aperture when the fitting is urged toward the window member while allowing the optical access through the second clear optical aperture and the first clear optical aperture into the chamber.    
   
   
       17 . A multi-function process chamber window assembly for protecting an access region for access to a process chamber from an electric field generated adjacent to the process chamber window while providing at least two gas inlets to the process chamber and allowing optical access to the chamber, the assembly comprising: 
 an integrated shield and gas supply unit for protecting the access region from the electric field, the unit having a thin three-dimensional protrusion at a first end and being configured with a body that is thicker than the protrusion, the body being further configured to extend from the first end parallel to an access region axis to a second end, the body being further configured with a first annular wall defining a unit clear aperture extending along the axis from the first end to the second end, the body being further configured with a first gas supply bore extending parallel to the axis and intersecting the unit clear optical aperture adjacent to the first end, the body being further configured with a first coupler, the unit being fabricated from material adapted to substantially block the electric field so that the unit clear optical aperture is protected from the electric field;    a window member configured with respect to the access region axis, the member being configured with outer and chamber sides and a groove extending from the outer side into the member, the groove extending parallel to the axis, the groove being configured to receive the thin protrusion to protect a first section of the access region from the electric field, the member being further configured with a second coupler configured to cooperate with the first coupler to hold the protrusion in the groove with the unit extending away from the outer side of the member so that a second section of the access region is defined by and is protected by the body from the electric field, the window member being further configured with a window member clear optical aperture having a second annular wall extending co-axially with the axis and configured with an axial length between the outer side and the chamber side, the window member clear optical aperture being partly surrounded by the thin protrusion received in the groove, the window member clear optical aperture being further configured with a diameter; and    a coating on the second annular wall, the second annular wall with the coating having an inner coating diameter that is substantially the same as a value of the axial length of the window member clear optical aperture, the coating protecting the window member clear optical aperture from the electric field, the material from which the coating is fabricated being taken from the group consisting of cerium oxide, zirconium oxide, yttria-stabilized zirconia, thermally-sprayed aluminum oxide, yttrium oxide, and yttrium oxide having pores, wherein the pores are sealed with a material taken from the group consisting of methacylate ester and polymer.    
   
   
       18 . An assembly as recited in  claim 17 , wherein: 
 the body of the unit is further configured with a second gas supply bore extending parallel to the axis and to the first end; and    the window member is further configured with a plenum extending from the outer side into the member, plenum receiving gas from the second gas supply bore, the window member being configured with a plurality of nozzles that are spaced around the axis and receive the gas from the plenum.    
   
   
       19 . An assembly as recited in  claim 17 , wherein: 
 the body of the unit is further configured with a pair of co-axial annular recesses, a first of the recesses is between the unit clear optical aperture and the second gas supply bore, a second of the recesses is between the second gas supply bore and the annular groove;    the assembly further comprises a seal member received in each of the recesses in opposition to the outer side of the window member; and    with the couplers holding the protrusion in the groove the outer side of the window member is held opposed to the seal members in the recesses to seal the second gas supply bore to the plenum and seal the unit clear optical aperture to the window member clear optical aperture while allowing optical access through the unit clear optical aperture and the window member clear optical aperture into the chamber.    
   
   
       20 . An assembly as recited in  claim 17 , wherein: 
 the second end of the body of the integrated unit is further configured with a seat;    the assembly further comprises an optical window configured for reception in the seat and a clamp for holding the optical window in the seat; and    the second end is spaced from the first end to locate the seat for the optical window where a strength of the electric field is substantially reduced as compared to an electric field strength adjacent to the process chamber window.