Ceramic coated article and process for applying ceramic coating

Abstract

To manufacture a ceramic article, a ceramic body comprising Al 2 O 3 is roughened to a roughness of approximately 140 micro-inches (μin) to 240 μin. The ceramic body is subsequently cleaned and then coated with a ceramic coating. The ceramic coating comprises a compound of Y 4 Al 2 O 9 (YAM) and a solid solution of Y 2 -xZr x O 3 . The ceramic coating is then polished.

What is claimed is: 
     
         1 . A method of manufacturing a ceramic article, comprising:
 roughening a ceramic body comprising Al 2 O 3  to a roughness of approximately 140 micro-inches (μin) to approximately 240 μin;   cleaning the ceramic body;   coating the ceramic body with a ceramic coating, wherein the ceramic coating comprises a yttrium containing oxide; and   machining the ceramic coating, wherein the ceramic article comprises the ceramic body and the ceramic coating.   
     
     
         2 . The method of  claim 1 , wherein the roughening is performed based on blasting the ceramic body with ceramic beads having a size range of 0.2-2 mm. 
     
     
         3 . The method of  claim 1 , wherein the cleaning comprises:
 cleaning the ceramic body using a first ultrasonic cleaning process in a de-ionized (DI) water bath;   subsequently cleaning the ceramic body using a second ultrasonic cleaning process in an acetone bath; and   subsequently cleaning the ceramic body using a third ultrasonic cleaning process in the DI water bath.   
     
     
         4 . The method of  claim 1 , further comprising:
 performing an additional cleaning of the ceramic article after performing the polishing.   
     
     
         5 . The method of  claim 1 , wherein machining the ceramic coating comprises polishing the ceramic coating, and wherein the ceramic coating has an initial thickness of approximately 17.5-21.0 mil before performing the polishing and a final thickness of approximately 8-10 mil after performing the polishing. 
     
     
         6 . The method of  claim 1 , wherein coating the ceramic body comprises:
 heating the ceramic body to a temperature of approximately 50° C. to 70° C.; and   plasma spraying the ceramic body using a plasma spray power of approximately 35 W to approximately 36.5 W.   
     
     
         7 . The method of  claim 1 , further comprising:
 applying a first mask to a region of the ceramic body prior to the roughening, wherein the region of the ceramic body is not roughened;   applying a second mask to the region of the ceramic body prior to the coating, wherein the region of the ceramic body is an uncoated region after the coating, and wherein the coating causes a rough edge to form at an interface between the uncoated region and a coated region; and   trimming the coating at the interface.   
     
     
         8 . The method of  claim 7 , wherein the first mask is a hard mask and the second mask is a soft mask. 
     
     
         9 . The method of  claim 1 , wherein a roughness of the ceramic coating after performing the polishing is approximately 6-12 μin. 
     
     
         10 . The method of  claim 1 , wherein the ceramic article is a lid for a plasma etcher configured to perform a conductor etch. 
     
     
         11 . The method of  claim 1 , wherein the ceramic coating comprises a compound of Y 4 Al 2 O 9  (YAM) and a solid solution of Y 2 -xZr x O 3 . 
     
     
         12 . A method comprising:
 applying a first mask to a first region of a ceramic body, wherein the first region is along an outer edge of the ceramic body and the ceramic body comprises Al 2 O 3 ;   roughening the ceramic body to a roughness of approximately 140 micro-inches (μin) to approximately 240 μin, wherein the first region of the ceramic body covered by the first mask is not roughened;   applying a second mask to the first region of the ceramic body;   coating the ceramic body with the ceramic coating using a mixture comprising a first ceramic powder of Y 2 O 3 , a second ceramic powder of ZrO 2  and a third ceramic powder of Al 2 O 3 , wherein the ceramic coating is formed from the first ceramic powder of Y 2 O 3 , the second ceramic powder of ZrO 2  and the third ceramic powder of Al 2 O 3 , and wherein the first region of the ceramic body is an uncoated region after the coating; and   polishing the ceramic coating, wherein the ceramic body comprises a hole, and wherein walls of the hole are not coated by the ceramic coating.   
     
     
         13 . The method of  claim 12 , wherein the ceramic coating comprises a compound of Y 4 Al 2 O 9  (YAM) and a solid solution of Y 2 -xZr x O 3 . 
     
     
         14 . The method of  claim 12 , wherein the ceramic coating has a final thickness of approximately 8-10 mil after performing the polishing. 
     
     
         15 . The method of  claim 12 , wherein coating the ceramic body comprises:
 heating the ceramic body to a temperature of approximately 50° C. to 70° C.; and   plasma spraying the ceramic body using a plasma spray power of approximately 35 W to 36.5 W while the ceramic body is heated.   
     
     
         16 . The method of  claim 12 , wherein the coating causes a rough edge to form at an interface between the uncoated region and a coated region of the ceramic body, the method further comprising:
 trimming the ceramic coating at the interface to remove the rough edge.   
     
     
         17 . The method of  claim 12 , wherein the ceramic body comprises a lid for a plasma etch reactor. 
     
     
         18 . The method of  claim 12 , wherein the ceramic coating comprises 55-77 mol % Y 2 O 3 , 15-23 mol % Z 2 O 3  and 8-25 mol % Al 2 O 3 . 
     
     
         19 . The method of  claim 12 , wherein the second region is coplanar with the first region and forms a ring around the first region. 
     
     
         20 . The method of  claim 12 , wherein the ceramic coating is polished to a roughness of approximately 6-12 μin.