Plasma etch resistant coating and process

Abstract

A protective coating is provided herein and methods of using the protective coating for susceptors used in semiconductor deposition chambers are described. In the preferred embodiments, CVD chamber equipment, such as a susceptor, is protected from plasma etch cleaning. Prior to CVD of silicon nitride, the chamber equipment is first coated with an emissivity-stabilizing layer, such as silicon nitride. This layer is then superficially oxidized. After repeated cycles of deposited silicon nitride upon different substrates in sequence, the chamber is emptied of wafers and a plasma cleaning process is conducted. Plasma cleaning is preferably selective against the silicon oxynitride protective coating. After the plasma cleaning process, the emissivity-stabilizing layer is reapplied, oxidized, and a plurality of deposition cycles can commence again.

We claim:  
     
         1 . A susceptor for a semiconductor reactor configured for plasma etch processing, the susceptor comprising a silicon oxynitride coating.  
     
     
         2 . The susceptor of  claim 1  wherein the susceptor is a SiC-coated graphite susceptor.  
     
     
         3 . The susceptor of  claim 1  wherein the reactor is configured for silicon nitride deposition.  
     
     
         4 . The susceptor of  claim 3  wherein the reactor is configured for plasma cleaning of reactor surfaces after a plurality of cycles of silicon nitride deposition.  
     
     
         5 . The susceptor of  claim 1 , wherein the silicon oxynitride coating directly overlies a silicon nitride coating.  
     
     
         6 . The susceptor of  claim 5 , wherein the silicon nitride coating has a thickness between about 500 Å and 2.0 μm.  
     
     
         7 . The susceptor of  claim 6 , wherein the silicon nitride coating has a thickness between about 0.5 μm and 1.0 μm.  
     
     
         8 . The susceptor of  claim 5 , wherein the silicon oxynitride coating has a thickness between about 5 Å and 200 Å.  
     
     
         9 . The susceptor of  claim 8 , wherein the silicon oxynitride coating has a thickness between about 10 Å and 15 Å.  
     
     
         10 . A chemical vapor deposition reactor, comprising: 
 a deposition chamber;    a substrate support within the chamber, the support having a silicon oxynitride coating;    a plurality of sources chemical vapor deposition reactant gases communicating selectively with the deposition chamber; and    a source of cleaning gas communicating selectively with the deposition chamber.    
     
     
         11 . The reactor of  claim 10 , further comprising an excited species generator communicating with the source of cleaning gas.  
     
     
         12 . The reactor of  claim 11 , wherein the excited species generator comprises a remote plasma generator.  
     
     
         13 . The reactor of  claim 11 , wherein the source of cleaning gas is selected to etch silicon nitride.  
     
     
         14 . The reactor of  claim 13 , wherein the source of cleaning gas comprises NF 3  and Cl 2 .  
     
     
         15 . The reactor of  claim 10 , wherein the plurality of source of chemical vapor deposition reactant gases are selected to deposit silicon nitride.  
     
     
         16 . The reactor of  claim 15 , further comprising a source of oxidizing gas.  
     
     
         17 . The reactor of  claim 14 , wherein the source of oxidizing gas is selected from the group consisting of oxygen, nitric oxide and nitrous oxide.  
     
     
         18 . The reactor of  claim 10 , wherein the support comprises a silicon carbide base below the silicon oynitride coating.  
     
     
         19 . The reactor of  claim 18 , wherein the silicon carbide base comprises a coating over a graphite core.  
     
     
         20 . The reactor of  claim 18 , wherein the support comprises a silicon nitride layer between the silicon carbide base and the silicon oxynitride coating.  
     
     
         21 . The reactor of  claim 20 , wherein the silicon nitride layer has a thickness between about 500 Å and 2.0 μm.  
     
     
         22 . The reactor of  claim 20 , further comprising a second layer of silicon nitride over the silicon oxynitride coating.  
     
     
         23 . The reactor of  claim 10 , wherein the silicon oxynitride coating has a thickness between about 5 Å and 200 Å.  
     
     
         24 . The reactor of  claim 10 , further comprising an additional structure comprising silicon carbide within the deposition chamber, the additional structure configured to remain stationary during chemical vapor deposition, the additional structure comprising an additional silicon oxynitride coating over the silicon carbide.  
     
     
         25 . The reactor of  claim 24 , wherein additional structure comprises a temperature compensation ring surrounding the substrate support.  
     
     
         26 . The reactor of  claim 24 , wherein the additional silicon oxynitride coating is non-uniform across the additional structure.  
     
     
         27 . The reactor of  claim 24 , wherein the additional silicon oxynitride coating has a thickness between about 5 Å and 200 Å.  
     
     
         28 . A structure in a radiantly heated chemical vapor deposition reactor, the structure comprising: 
 a silicon carbide base;    a silicon nitride layer overlying the silicon carbide base; and    a silicon oynitride layer overlying the silicon nitride layer.    
     
     
         29 . The structure of  claim 28 , wherein the silicon carbide base comprises a coating over a graphite core.  
     
     
         30 . The structure of  claim 28 , comprising a susceptor.  
     
     
         31 . The structure of  claim 28 , comprising a temperature compensation ring.  
     
     
         32 . The structure of  claim 28 , wherein the silicon nitride layer has a thickness between about 500 Å and 2.0 μm and the silicon oxynitride layer has a thickness between about 5 Å and 200 Å.