Methods for preparing void-free coatings for plasma treatment components

Abstract

Methods for preparing a void-free protective coating are disclosed herein. The void-free protective coating is used on a dielectric window having a central hole, which is used in a plasma treatment tool. A first protective coating layer is applied to the window, leaving an uncoated annular retreat area around the central hole. The first protective coating layer is polished to produce a flat surface and fill in any voids on the window. A second protective coating layer is then applied upon the flat surface of the first protective coating layer to obtain the void-free coating. This increases process uptime and service lifetime of the dielectric window and the plasma treatment tool.

What is claimed is: 
     
         1 . A plasma treatment tool, comprising:
 a housing;   an upper electrode;   a dielectric window separating the upper electrode from a wafer support surface, the dielectric window including a void-free protective coating oriented toward the wafer support surface and having an uncoated annular retreat area around a central hole therein;   a lower electrode below the wafer support surface; and   a radiofrequency (RF) generator for applying an electromagnetic field within the housing.   
     
     
         2 . The plasma treatment tool of  claim 1 , wherein the dielectric window is made from a ceramic or anodized aluminum. 
     
     
         3 . The plasma treatment tool of  claim 1 , wherein the protective coating comprises Y 2 O 3 , YOF, or YAG. 
     
     
         4 . The plasma treatment tool of  claim 1 , wherein the uncoated annular retreat area has a width of greater than 0 micrometers (μm) to about 2000 μm. 
     
     
         5 . The plasma treatment tool of  claim 1 , wherein the void-free coating has a thickness of about 100 μm or less. 
     
     
         6 . The plasma treatment tool of  claim 1 , wherein the void-free coating has a surface roughness of less than 0.5 μm. 
     
     
         7 . The plasma treatment tool of  claim 1 , wherein the void-free coating has a Vickers hardness (Hv) of about 700 or greater and a crystallinity of about 80% or greater. 
     
     
         8 . A method of plasma treating a semiconducting wafer substrate, comprising:
 placing the semiconducting wafer substrate on a wafer support surface of a plasma treatment tool that comprises a dielectric window located between the wafer support surface and an upper electrode; and   plasma treating the semiconducting wafer substrate;   wherein the dielectric window includes a void-free protective coating oriented toward the wafer support surface and has an uncoated annular retreat area around a central hole therein.   
     
     
         9 . The method of  claim 8 , wherein the dielectric window is made from a ceramic or anodized aluminum or silicon dioxide 
     
     
         10 . The method of  claim 8 , wherein the protective coating comprises Y 2 O 3 , YOF, or YAG. 
     
     
         11 . The method of  claim 8 , wherein the uncoated annular retreat area has a width of greater than 0 micrometers (μm) to about 2000 μm. 
     
     
         12 . The method of  claim 8 , wherein the void-free coating has a thickness of about 100 μm or less. 
     
     
         13 . The method of  claim 8 , wherein the void-free coating has a surface roughness of less than 0.5 μm. 
     
     
         14 . The method of  claim 8 , wherein the void-free coating has a Vickers hardness (Hv) of about 700 or greater. 
     
     
         15 . The method of  claim 8 , wherein the void-free coating has a crystallinity of about 80% or greater. 
     
     
         16 . The method of  claim 8 , wherein the void-free protective coating comprises a first protective coating layer and a second protective coating layer. 
     
     
         17 . A method of plasma treating a semiconducting wafer substrate, comprising:
 placing the semiconducting wafer substrate on a wafer support surface of a plasma treatment tool that comprises a dielectric window located between the wafer support surface and an upper electrode; and   plasma treating the semiconducting wafer substrate;   wherein the dielectric window includes a void-free protective coating oriented toward the wafer support surface and has an uncoated annular retreat area around a central hole therein; and   wherein the void-free protective coating comprises a first protective coating layer and a second protective coating layer.   
     
     
         18 . The method of  claim 17 , wherein the first protective coating layer and the second protective coating layer comprise yttrium. 
     
     
         19 . The method of  claim 18 , wherein the first protective coating layer and the second protective coating layer independently comprise Y 2 O 3 , YOF, or YAG. 
     
     
         20 . The method of  claim 17 , wherein the first protective coating layer and the second protective coating layer are applied using physical vapor deposition.