Method and apparatus for controlling temperature of a substrate

Abstract

A pedestal assembly and method for controlling temperature of a substrate during processing is provided. In one embodiment, the pedestal assembly includes a support member that is coupled to a base by a material layer. The material layer has at least two regions having different coefficients of thermal conductivity. In another embodiment, the support member is an electrostatic chuck. In further embodiments, a pedestal assembly has channels formed between the base and support member for providing cooling gas in proximity to the material layer to further control heat transfer between the support member and the base, thereby controlling the temperature profile of a substrate disposed on the support member.

1 . A substrate pedestal assembly comprising: 
 a substrate support member;    a base having a first surface; and    a material layer disposed between and contacting the first surface and the support member, wherein the material layer comprises a plurality of material regions, at least two of the material regions having different coefficients of thermal conductivity.    
   
   
       2 . The substrate pedestal assembly of  claim 1 , wherein at least one region of the plurality of material regions has an anisotropic coefficient of thermal conductivity.  
   
   
       3 . The substrate pedestal assembly of  claim 1 , wherein at least one region of the plurality of material regions is separated by a gap from an adjacent material region.  
   
   
       4 . The substrate pedestal assembly of  claim 1 , wherein the material layer couples the support member to the first surface of the base.  
   
   
       5 . The substrate pedestal assembly of  claim 4 , wherein at least one region of the material layer is thermally conductive adhesive material.  
   
   
       6 . The substrate pedestal assembly of  claim 4 , wherein at least one region of the material layer comprises at least one thermally conductive adhesive tape.  
   
   
       7 . The substrate pedestal assembly of  claim 4 , wherein the material layer is at least one of an acrylic based compound and silicon based compound.  
   
   
       8 . The substrate support pedestal assembly of  claim 1 , wherein the material layer further comprises a ceramic filler selected from the group consisting of aluminum oxide (Al 2 O 3 ), aluminum nitride (AlN), titanium diboride (TiB 2 ), and combinations thereof.  
   
   
       9 . The substrate pedestal assembly of  claim 1 , wherein the regions of the material layer have coefficients of thermal conductivity in a range from 0.01 to 200 W/mK.  
   
   
       10 . The substrate pedestal assembly of  claim 1  further comprising at least one channel adapted to provide a heat transfer medium between the base and support member.  
   
   
       11 . The substrate pedestal assembly of  claim 10 , wherein the at least one channel is at least partially formed in the base.  
   
   
       12 . The substrate pedestal assembly of  claim 10 , wherein the at least one is at least partially formed in the support member.  
   
   
       13 . The substrate pedestal assembly of  claim 10 , wherein the pressure of the heat transfer medium in the at least one channel may be selectively controlled in a range from about 760 to about 10 Torr.  
   
   
       14 . The substrate pedestal assembly of  claim 10 , wherein the heat transfer medium is He.  
   
   
       15 . The substrate pedestal assembly of  claim 10 , wherein the at least one channel is formed in the material layer.  
   
   
       16 . The substrate pedestal assembly of  claim 1 , wherein the base comprises at least one conduit fluidly coupled to a heat transfer liquid source.  
   
   
       17 . The substrate pedestal assembly of  claim 10 , wherein the channel is formed between material regions having different coefficients of thermal expansion.  
   
   
       18 . The substrate pedestal assembly of  claim 1 , wherein the base comprises at least one embedded heater electrically coupled to a controlled power supply.  
   
   
       19 . The substrate pedestal assembly of  claim 1 . wherein the base comprises at least one embedded insert formed from a material having a different coefficient of thermal conductivity than a material of an adjacent region of the base.  
   
   
       20 . The substrate pedestal assembly of  claim 19 , wherein the material of the at least one embedded insert has a lower coefficient of thermal conductivity than the material of the adjacent region of the base.  
   
   
       21 . The substrate pedestal assembly of  claim 19 , wherein the material of the at least one embedded insert has an anisotropic coefficient of thermal conductivity.  
   
   
       22 . The substrate pedestal assembly of  claim 1 , wherein the support member comprises at least one embedded insert formed from a material having a different coefficient of thermal conductivity than a material of an adjacent region of the support member.  
   
   
       23 . The substrate pedestal assembly of  claim 22 , wherein the material of the at least one embedded insert has a lower coefficient of thermal conductivity than the material of the adjacent region of the support member.  
   
   
       24 . The substrate pedestal assembly of  claim 22 , wherein the material of the at least one embedded insert has an anisotropic coefficient of thermal conductivity.  
   
   
       25 . The substrate pedestal assembly of  claim 1 , wherein a support member is an electrostatic chuck.