Silicon containing confinement ring for plasma processing apparatus and method of forming thereof

Abstract

A method of forming a silicon containing confinement ring for a plasma processing apparatus useful for processing a semiconductor substrate comprises inserting silicon containing vanes into grooves formed in a grooved surface of an annular carbon template wherein the grooved surface of the annular carbon template includes an upwardly projecting step at an inner perimeter thereof wherein each groove extends from the inner perimeter to an outer perimeter of the grooved surface. The step of the grooved surface and a projection at an end of each silicon containing vane is surrounded with an annular carbon member wherein the annular carbon member covers an upper surface of each silicon containing vane in each respective groove. Silicon containing material is deposited on the annular carbon template, the annular carbon member, and exposed portions of each silicon containing vane thereby forming a silicon containing shell of a predetermined thickness. A portion of the silicon containing shell is removed and the annular carbon template and the annular carbon member are removed from the silicon containing shell leaving a silicon containing confinement ring wherein the silicon containing vanes are supported by the silicon containing shell of the silicon containing confinement ring.

What is claimed is: 
     
         1 . A silicon containing confinement ring for a plasma processing apparatus comprising:
 silicon containing vanes embedded in a silicon containing shell, the silicon containing shell including an upper annular wall which extends horizontally;   a sidewall extending vertically downward from an outer end of the upper wall; and   a lower annular wall extending horizontally inward from a lower end of the sidewall, the lower annular wall including circumferentially spaced apart radially extending slots formed by the silicon containing vanes, each of the slots having a length of at least 1.0 inch and a uniform width of about 0.01 to 0.2 inch, and a height of about 0.25 inch or greater, the slots being evenly spaced at radial positions offset by no more than 2°.   
     
     
         2 . The silicon containing confinement ring of  claim 1 , wherein the upper annular wall includes an annular flange at an inner end thereof adapted to underlie an outer edge of an upper electrode of the plasma processing apparatus and wherein the lower wall includes a downwardly extending annular projection at an inner perimeter thereof. 
     
     
         3 . The silicon containing confinement ring of  claim 1 , wherein each silicon containing vane has a uniform thickness of about 0.08 inch or less and the silicon containing vanes are evenly spaced at radial positions offset by 2° or less. 
     
     
         4 . The silicon containing confinement ring of  claim 1 , wherein the silicon containing confinement ring is formed from silicon or silicon carbide. 
     
     
         5 . The silicon containing confinement ring of  claim 1 , made by a process comprising:
 inserting silicon containing vanes into grooves formed in a grooved surface of an annular carbon template wherein the grooved surface of the annular carbon template includes an upwardly projecting step at an inner perimeter thereof wherein each groove extends from the inner perimeter to an outer perimeter of the grooved surface;   surrounding the step of the grooved surface with an annular carbon member wherein the annular carbon member covers an upper surface of each silicon containing vane in each respective groove;   depositing silicon containing material on the annular carbon template, the annular carbon member, and exposed portions of each silicon containing vane thereby forming a silicon containing shell of a predetermined thickness;   removing a portion of the silicon containing shell; and   removing the annular carbon template and the annular carbon member from the silicon containing shell leaving a silicon containing confinement ring wherein the silicon containing vanes are supported by the silicon containing shell of the silicon containing confinement ring.   
     
     
         6 . The silicon containing confinement ring of  claim 5 , made by a process further comprising machining graphite to form the annular carbon template with an inner diameter of at least about 12 inches and the annular carbon member with an inner diameter larger than the inner diameter of the annular carbon template. 
     
     
         7 . The silicon containing confinement ring of  claim 5 , made by a process wherein depositing silicon containing material on the annular carbon template, annular carbon member, and exposed portions of the silicon containing vanes includes supporting the annular carbon template or the annular carbon member at a region which underlies a portion of the silicon containing shell which is removed to form the silicon containing confinement ring. 
     
     
         8 . The silicon containing confinement ring of  claim 5 , made by a process wherein the silicon containing material is deposited on the annular carbon template, the annular carbon member, and exposed portions of each silicon containing vane by chemical vapor deposition, or plasma enhanced chemical vapor deposition. 
     
     
         9 . The silicon containing confinement ring of  claim 5 , made by a process further comprising performing an oxidation process on the silicon containing confinement ring to clean the outer surfaces thereof and finishing grinding the silicon containing confinement ring to final dimensions. 
     
     
         10 . The silicon containing confinement ring of  claim 5 , made by a process further comprising forming the silicon containing vanes by electrical discharge machining a flat plate of CVD silicon containing material to form vanes with a length of about 1.5 to 4.5 inches, a height of about 0.1 to 2 inches, a thickness of about 0.08 inch or less, wherein each silicon containing vane includes a projection at an end thereof extending at least about 0.17 inch or more from an upper surface thereof. 
     
     
         11 . The silicon containing confinement ring of  claim 5 , made by a process wherein the annular carbon template and the annular carbon member are removed from the silicon containing shell by heating the silicon containing shell which contains the annular carbon template and the annular carbon member to 600° C. or greater in an oxygen-containing atmosphere to remove the carbon from the interior region of the silicon containing shell thereby leaving the silicon containing confinement ring. 
     
     
         12 . The silicon containing confinement ring of  claim 1 , wherein internally threaded bosses are attached to an upper surface of the silicon containing confinement ring. 
     
     
         13 . The silicon containing confinement ring of  claim 1 , further comprising an electrically conductive coating on a lower surface of the silicon containing confinement ring adapted to enhance electrical contact with an adjacent component when installed in the plasma processing apparatus. 
     
     
         14 . The silicon containing confinement ring of  claim 5 , made by a process wherein the silicon containing material depositing step forms the silicon containing shell to a thickness of about 0.03 to about 0.09 inch. 
     
     
         15 . The silicon containing confinement ring of  claim 1 , comprising 150 to 1000 silicon containing vanes. 
     
     
         16 . A method of processing a semiconductor substrate in a plasma processing apparatus including the silicon containing confinement ring of  claim 1 , the method comprising:
 transporting a semiconductor substrate into the plasma processing apparatus and supporting the substrate on a substrate support;   introducing a process gas into a confined chamber volume of the plasma processing apparatus wherein an outer perimeter of the confined chamber volume is defined by at least the silicon containing confinement ring;   energizing the process gas into a plasma state;   processing the semiconductor substrate with the plasma; and   withdrawing process gases and byproducts of the processing through the slots and out of the chamber.   
     
     
         17 . The method of  claim 16 , wherein the processing includes plasma etching openings in a dielectric material using fluorocarbon and/or hydrofluorocarbon etching gas. 
     
     
         18 . The method of  claim 16 , wherein the processing includes deposition of conductive or dielectric material on the semiconductor substrate.