Light-up prevention in electrostatic chucks

Abstract

An electrostatic chuck assembly is provided comprising a ceramic contact layer, a patterned bonding layer, an electrically conductive base plate, and a subterranean arc mitigation layer. The ceramic contact layer and the electrically conductive base plate cooperate to define a plurality of hybrid gas distribution channels formed in a subterranean portion of the electrostatic chuck assembly. Individual ones of the hybrid gas distribution channels comprise surfaces of relatively high electrical conductivity presented by the electrically conductive base plate and relatively low electrical conductivity presented by the ceramic contact layer. The subterranean arc mitigation layer comprises a layer of relatively low electrical conductivity and is formed over the relatively high conductivity surfaces of the hybrid gas distribution channels in the subterranean portion of the electrostatic chuck assembly. Semiconductor wafer processing chambers are also provided.

1 . An electrostatic chuck assembly comprising a ceramic contact layer, a patterned bonding layer, an electrically conductive base plate, and a subterranean arc mitigation layer, wherein:
 the patterned bonding layer is configured to secure the ceramic contact layer to the electrically conductive base plate;   the ceramic contact layer and the electrically conductive base plate cooperate to define a plurality of hybrid gas distribution channels formed in a subterranean portion of the electrostatic chuck assembly;   the ceramic contact layer comprises a contact face and a plurality of coolant ports formed in the contact face of the ceramic contact layer;   the coolant ports are in fluid communication with the hybrid gas distribution channels of the electrostatic chuck assembly;   individual ones of the hybrid gas distribution channels comprise surfaces of relatively high electrical conductivity presented by the electrically conductive base plate and relatively low electrical conductivity presented by the ceramic contact layer; and   the subterranean arc mitigation layer comprises a layer of relatively low electrical conductivity and is formed over the relatively high conductivity surfaces of the hybrid gas distribution channels in the subterranean portion of the electrostatic chuck assembly.   
     
     
         2 . An electrostatic chuck assembly as claimed in  claim 1  wherein the subterranean arc mitigation layer comprises a dielectric layer characterized by a thickness that is at least approximately 75 μm but less than approximately 350 μm. 
     
     
         3 . An electrostatic chuck assembly as claimed in  claim 1  wherein the subterranean arc mitigation layer comprises a dielectric layer characterized by a thickness that is less than approximately 35% of a thickness of the ceramic contact layer. 
     
     
         4 . An electrostatic chuck assembly as claimed in  claim 1  wherein the subterranean arc mitigation layer comprises a spray-on dielectric coating. 
     
     
         5 . An electrostatic chuck assembly as claimed in  claim 1  wherein the subterranean arc mitigation layer comprises a spray-on alumina coating. 
     
     
         6 . An electrostatic chuck assembly as claimed in  claim 1  wherein the subterranean arc mitigation layer comprises a spray-on alumina dielectric layer characterized by a thickness less than approximately 350 μm. 
     
     
         7 . An electrostatic chuck assembly as claimed in  claim 1  wherein the subterranean arc mitigation layer comprises a continuous or discontinuous anodized layer or a layer of alumina, Yttria, YAG, or combinations thereof. 
     
     
         8 . An electrostatic chuck assembly as claimed in  claim 1  wherein the subterranean arc mitigation layer comprises a discontinuous layer comprising portions of relatively low conductivity material limited to the hybrid gas distribution channels or regions disposed relatively adjacent thereto. 
     
     
         9 . An electrostatic chuck assembly as claimed in  claim 1  wherein the hybrid gas distribution channels formed in the subterranean portion of the electrostatic chuck assembly comprise counter-bored grooves formed in a surface of the electrically conductive base plate, a surface of the ceramic contact layer, or both. 
     
     
         10 . An electrostatic chuck assembly as claimed in  claim 1  wherein gas distribution channel surfaces of relatively high electrical conductivity are presented by counter-bored grooves formed in a surface of the electrically conductive base plate. 
     
     
         11 . An electrostatic chuck assembly as claimed in  claim 10  wherein gas distribution channel surfaces of relatively low electrical conductivity are presented by a backside face of the ceramic contact layer. 
     
     
         12 . An electrostatic chuck assembly as claimed in  claim 10  wherein gas distribution channel surfaces of relatively low electrical conductivity are presented by one or more sidewall faces of the ceramic contact layer. 
     
     
         13 . An electrostatic chuck assembly as claimed in  claim 1  wherein gas distribution channel surfaces of relatively low electrical conductivity are presented by counter-bored grooves formed in the ceramic contact layer. 
     
     
         14 . An electrostatic chuck assembly as claimed in  claim 13  wherein gas distribution channel surfaces of relatively high electrical conductivity are presented by a frontside face of the electrically conductive base plate. 
     
     
         15 . An electrostatic chuck assembly as claimed in  claim 1  wherein the ceramic contact layer comprises an alumina dielectric, an alumina and titanium dioxide dielectric, aluminum nitride, silicon nitride, silicon carbide, boron nitride, yttria, yttrium aluminate, or any combination thereof, with or without trace impurities. 
     
     
         16 . An electrostatic chuck assembly as claimed in  claim 1  wherein the patterned bonding layer comprises a pattern of voids aligned with the hybrid gas distribution channels. 
     
     
         17 . An electrostatic chuck assembly as claimed in  claim 1  wherein the patterned bonding layer comprises silicone. 
     
     
         18 . An electrostatic chuck assembly as claimed in  claim 1  wherein the patterned bonding layer comprises an adhesive. 
     
     
         19 . An electrostatic chuck assembly comprising a ceramic contact layer, a silicone patterned bonding layer, an electrically conductive base plate, and a subterranean arc mitigation layer, wherein:
 the patterned bonding layer is configured to secure the ceramic contact layer to the electrically conductive base plate;   the ceramic contact layer and the electrically conductive base plate cooperate to define a plurality of hybrid gas distribution channels formed in a subterranean portion of the electrostatic chuck assembly;   the hybrid gas distribution channels comprise counter-bored grooves formed in a surface of the electrically conductive base plate, a surface of the ceramic contact layer, or both;   the ceramic contact layer comprises a contact face and a plurality of coolant ports formed in the contact face of the ceramic contact layer;   the coolant ports are in fluid communication with the hybrid gas distribution channels of the electrostatic chuck assembly;   individual ones of the hybrid gas distribution channels comprise surfaces of relatively high electrical conductivity presented by the electrically conductive base plate and relatively low electrical conductivity presented by the ceramic contact layer;   the subterranean arc mitigation layer comprises a spray-on alumina dielectric layer characterized by a thickness less than approximately 350 μm formed over the relatively high conductivity surfaces of the hybrid gas distribution channels in the subterranean portion of the electrostatic chuck assembly.   
     
     
         20 . A semiconductor wafer processing chamber comprising an electrostatic chuck assembly, a processing chamber, a voltage source, and a supply of coolant gas, wherein:
 the electrostatic chuck assembly is positioned in the processing chamber and comprises a ceramic contact layer, a patterned bonding layer, an electrically conductive base plate, and a subterranean arc mitigation layer;   the voltage source is coupled electrically to the electrically conductive base plate;   the patterned bonding layer is configured to secure the ceramic contact layer to the electrically conductive base plate;   the ceramic contact layer and the electrically conductive base plate cooperate to define a plurality of hybrid gas distribution channels formed in a subterranean portion of the electrostatic chuck assembly;   the supply of coolant gas is coupled fluidly to the hybrid gas distribution channels;   the ceramic contact layer comprises a contact face and a plurality of coolant ports formed in the contact face of the ceramic contact layer;   the coolant ports are in fluid communication with the hybrid gas distribution channels of the electrostatic chuck assembly;   individual ones of the hybrid gas distribution channels comprise surfaces of relatively high electrical conductivity presented by the electrically conductive base plate and relatively low electrical conductivity presented by the ceramic contact layer; and   the subterranean arc mitigation layer comprises a layer of relatively low electrical conductivity and is formed over the relatively high conductivity surfaces of the hybrid gas distribution channels in the subterranean portion of the electrostatic chuck assembly.