Plasma spray coating enhancement using plasma flame heat treatment

Abstract

A method for forming a plasma resistant ceramic coating on an article includes placing the article into a chamber or spray cell of a plasma spraying system. A ceramic powder is then fed into the plasma spraying system at a powder feed rate, and a plasma resistant ceramic coating is deposited onto at least one surface of the article in a plasma spray process by the plasma spray system. The plasma spray system is then used to perform an in-situ plasma flame heat treatment of the plasma resistant ceramic coating to form crust on the plasma resistant ceramic coating.

What is claimed is: 
     
         1 . A chamber component for a plasma etch reactor, the chamber component comprising:
 a plasma resistant ceramic coating on at least one surface of a body of the chamber component, wherein the plasma resistant ceramic coating has a porosity of 1-5%, and wherein the plasma resistant ceramic coating consists essentially of a material selected from a group consisting of Er 2 O 3 , Gd 2 O 3 , Er 3 Al 5 O 12 , Gd 3 Al 5 O 12 , and Nd 2 O 3 , and wherein the plasma resistant ceramic coating does not comprise Y 2 O 3 , Y 3 Al 5 O 12 , or YF 3 ; and   a crust on a surface of the plasma resistant ceramic coating, the crust having a thickness of less than about 50 microns and a porosity that is lower than the porosity of the plasma resistant ceramic coating.   
     
     
         2 . The chamber component of  claim 1 , wherein the crust has a surface roughness of about 100-150 micro-inches. 
     
     
         3 . The chamber component of  claim 1 , wherein the plasma resistant ceramic coating consists of Er 2 O 3 . 
     
     
         4 . The chamber component of  claim 1 , wherein the plasma resistant ceramic coating consists of Er 3 Al 5 O 12 . 
     
     
         5 . The chamber component of  claim 1 , wherein the body comprises at least one of a metal or a sintered ceramic. 
     
     
         6 . The chamber component of  claim 1 , wherein the plasma resistant ceramic coating comprises at least one of loosely bonded particles, partially melted surface nodules, or surface cracks, and wherein the crust is free of the at least one of the loosely bonded particles, the partially melted surface nodules, or the surface cracks. 
     
     
         7 . The chamber component of  claim 1 , wherein the chamber component is formed by:
 depositing the plasma resistant ceramic coating on the at least one surface of the body in a plasma spray process by a plasma spraying system; and   performing an in-situ plasma flame heat treatment of the plasma resistant ceramic coating by the plasma spraying system to form the crust on the plasma resistant ceramic coating.   
     
     
         8 . The chamber component of  claim 7 , the in-situ plasma flame heat treatment having been performed for approximately 0.5-20 minutes. 
     
     
         9 . The chamber component of  claim 7 , wherein performing the in-situ plasma flame heat treatment comprises:
 adjusting at least one of a plasma power, a gun moving speed or a gun distance of the plasma spraying system; and   reducing a powder feed rate of ceramic powder to zero.   
     
     
         10 . The chamber component of  claim 7 , wherein the plasma spraying system is an atmospheric pressure plasma spray system. 
     
     
         11 . A chamber component for a plasma etch reactor, the chamber component having a plasma resistant ceramic coating on at least one surface, the plasma resistant ceramic coating having been formed by a process comprising:
 depositing a plasma resistant ceramic coating on at least one surface of an article in a plasma spray process, wherein the plasma resistant ceramic coating consists essentially of a material selected from a group consisting of Er 2 O 3 , Gd 2 O 3 , Er 3 Al 5 O 12 , Gd 3 Al 5 O 12 , and Nd 2 O 3 , and wherein the plasma resistant ceramic coating does not comprise Y 2 O 3 , Y 3 Al 5 O 12 , or YF 3 ; and   performing an in-situ plasma flame heat treatment of the plasma resistant ceramic coating to form a crust on the plasma resistant ceramic coating.   
     
     
         12 . The chamber component of  claim 11 , wherein depositing the plasma resistant ceramic coating comprises:
 feeding a ceramic powder into an atmospheric pressure plasma spraying system at a powder feed rate.   
     
     
         13 . The chamber component of  claim 12 , wherein performing the in-situ plasma flame heat treatment comprises:
 adjusting at least one of a plasma power, a gun moving speed or a gun distance of the atmospheric plasma spraying system; and   reducing the powder feed rate of the ceramic powder to zero.   
     
     
         14 . The chamber component of  claim 11 , wherein the plasma resistant ceramic coating has a porosity of 1-5% and a thickness of at least 100 microns, and wherein the crust has a lower porosity than the plasma resistant ceramic coating and a thickness of greater than 0 microns to less than about 50 microns. 
     
     
         15 . The chamber component of  claim 11 , wherein the crust has a surface roughness of about 100-150 micro-inches. 
     
     
         16 . The chamber component of  claim 11 , wherein the plasma resistant ceramic coating consists of Er 2 O 3 . 
     
     
         17 . The chamber component of  claim 11 , wherein the plasma resistant ceramic coating consists of Er 3 Al 5 O 12 . 
     
     
         18 . The chamber component of  claim 11 , wherein the article comprises at least one of a metal or a sintered ceramic. 
     
     
         19 . The chamber component of  claim 11 , wherein the plasma resistant ceramic coating comprises at least one of loosely bonded particles, partially melted surface nodules, or surface cracks, and wherein the crust is free of the at least one of the loosely bonded particles, the partially melted surface nodules, or the surface cracks. 
     
     
         20 . A chamber component for a plasma etch reactor, the chamber component having a plasma resistant ceramic coating on at least one surface, the plasma resistant ceramic coating having been formed by a process comprising:
 feeding a ceramic powder into a plasma spraying system at a powder feed rate of 5-200 grams per minute;   depositing a plasma resistant ceramic coating on a surface of an article in a plasma spray process by the plasma spraying system, wherein the plasma spray process is performed using a plasma power of 9-300 kW, a gun current of 300-1000 Amps, a gun voltage of 30-300 Volts, the powder feed rate of 5-200 grams per minute, a torch offset distance of 50-200 mm and a gas flow rate of 30-500 Liters per minute, wherein the plasma resistant ceramic coating consists essentially of a material selected from a group consisting of Er 2 O 3 , Gd 2 O 3 , Er 3 Al 5 O 12 , Gd 3 Al 5 O 12 , and Nd 2 O 3 , wherein the plasma resistant ceramic coating does not comprise Y 2 O 3 , Y 3 Al 5 O 12 , or YF 3 , and wherein the plasma resistant ceramic coating has a thickness of about 100 microns to about 650 microns, has a porosity of 1-5%, has a surface roughness of about 160-250 micro-inches, and comprises a plurality of loosely bonded particles, a plurality of partially melted surface nodules, a plurality of surface cracks and a plurality of pores at the surface of the article;   reducing the powder feed rate of the ceramic powder to zero grams per minute; adjusting at least one of the plasma power, a gun moving speed or the torch offset distance of the plasma spraying system; and   performing an in-situ plasma flame heat treatment of the plasma resistant ceramic coating by the plasma spraying system to cause a surface of the plasma resistant ceramic coating to melt and reflow to form a crust on the plasma resistant ceramic coating, wherein the in-situ plasma flame heat treatment is performed using 35-300 kW for the plasma power, 500-1000 Amps for the gun current, 70-300 Volts for the gun voltage, 20-100 mm for the torch offset distance and 50-500 Liters per minute for the gas flow rate, wherein the crust has a thickness of above 0 microns to less than about 50 microns, has a porosity that is less than the porosity of the plasma resistant ceramic coating, has a surface roughness of about 100-150 micro-inches, and lacks at least some of the plurality of loosely bonded particles, at least some of the plurality of partially melted surface nodules, at least some of the plurality of surface cracks and at least some of the plurality of pores at the surface of the article.