Heated substrate support and method of fabricating same

Abstract

A method and apparatus for forming a substrate support is provided herein. In one embodiment, the substrate support includes a body having a support surface and at least one groove. A heater element clad with a malleable heat sink is disposed in the groove. Substantially no air is trapped between the clad heater element and the groove. An insert is disposed in the groove above the heater. The insert substantially completely covers and contacts the clad heater element and the sides of the groove. A cap is disposed in the groove above the insert. The cap covers and contacts the insert and has an upper surface disposed substantially flush with the support surface.

1 . A substrate support comprising: 
 a body having a support surface;    at least one groove formed in the body;    a heater element disposed within the groove; and    a heat sink circumscribing the heater element and in contact with the heater element and the body.    
   
   
       2 . The substrate support of  claim 1 , wherein the heat sink comprises: 
 aluminum having a greater thermal conductivity than the body.    
   
   
       3 . The substrate support of  claim 1 , wherein the heat sink comprises: 
 an aluminum alloy selected from series 1100 to series 3000-100 aluminum.    
   
   
       4 . The substrate support of  claim 1 , wherein the heat sink comprises aluminum 3004.  
   
   
       5 . The substrate support of  claim 1 , wherein the heat sink is annealed.  
   
   
       6 . The substrate support of  claim 1 , wherein substantially no air is disposed between the heat sink and the heater element.  
   
   
       7 . The substrate support of  claim 1 , wherein opposing walls of the groove are flared outward.  
   
   
       8 . The substrate support of  claim 7 , wherein the walls of the groove are angled outward at an enclosed angle of less than about three degrees.  
   
   
       9 . The substrate support of  claim 1 , further comprising: 
 a channel formed proximate the bottom of the groove, wherein the channel is substantially filled with the heat sink.    
   
   
       10 . The substrate support of  claim 1 , further comprising: 
 an insert disposed in the groove above the heater element.    
   
   
       11 . The substrate support of  claim 10  further comprising: 
 one or more air relief holes formed through the insert.    
   
   
       12 . The substrate support of  claim 10 , wherein the insert comprises the same material as the heat sink.  
   
   
       13 . The substrate support of  claim 1 , further comprising: 
 a cap disposed in the groove.    
   
   
       14 . The substrate support of  claim 13 , wherein the cap has an outer surface disposed substantially co-planar with the support surface.  
   
   
       15 . The substrate support of  claim 13 , wherein the cap comprises the same material as the body.  
   
   
       16 . The substrate support of  claim 13 , wherein the cap is at least one of welded or forged in place.  
   
   
       17 . The substrate support of  claim 13 , wherein the cap forms a pressure seal between the heater element and an atmosphere outside of the substrate support.  
   
   
       18 . The substrate support of  claim 1 , further comprising: 
 a pressure seal disposed between the heater element and an atmosphere disposed outside of the substrate support.    
   
   
       19 . The substrate support of  claim 1 , wherein a bottom surface of the groove is roughened.  
   
   
       20 . The substrate support of  claim 1 , wherein the support surface has a support area that is greater than or equal to about 550 by about 650 millimeters.  
   
   
       21 . The substrate support of  claim 1 , wherein the support surface has a support area that is greater than or equal to about 1500 by about 1800 millimeters.  
   
   
       22 . The substrate support of  claim 1 , wherein the support surface has a support area that is substantially polygonal.  
   
   
       23 . The substrate support of  claim 1 , wherein the body comprises aluminum.  
   
   
       24 . A substrate support, comprising: 
 an aluminum body having a support surface and at least one groove;    a heater element clad with a malleable heat sink and press fit into the groove;    an insert disposed in the groove, wherein the insert contacts the heater element and the sides of the groove; and    a cap disposed in the groove, the cap having an outer surface disposed substantially flush with the body.    
   
   
       25 . The substrate support of  claim 24 , wherein the heat sink comprises: 
 an aluminum alloy in the range of from about aluminum 1100 to about aluminum 3000-100 series.    
   
   
       26 . The substrate support of  claim 24 , wherein the heat sink comprises: 
 aluminum 3004.    
   
   
       27 . A method of forming a substrate support, comprising: 
 providing a body having at least one groove formed in a surface thereof;    inserting a heater element into the groove, wherein the heater element is encased in an outer cladding having substantially no air pockets trapped between the cladding and the heater element, the cladding adapted to be a heat sink;    disposing an insert in the groove over the clad heater element; and    inserting a cap into the groove, wherein an outer surface of the cap is disposed substantially flush with the body.    
   
   
       28 . The method of  claim 27 , wherein the cladding comprises: 
 an aluminum alloy in the range of from about aluminum 1100 to about aluminum 3000-100 series.    
   
   
       29 . A method of forming a substrate support, comprising: 
 providing a body having at least one groove formed in a support surface thereof;    inserting a heater element into the groove, the heater element clad with a material softer than the body and adapted to be a heat sink;    covering the clad heater element with an insert disposed in the groove; and    capping the groove with a cap having an upper surface disposed substantially flush with the upper support surface.    
   
   
       30 . The method of  claim 29 , further comprising: 
 venting gas from between the heater element and the body through a channel provided proximate a bottom of the groove.    
   
   
       31 . The method of  claim 29 , further comprising: 
 venting gas from between the heater element and the insert through a plurality of holes formed in and extending through the insert.    
   
   
       32 . The method of  claim 29 , wherein the step of providing a body further comprises: 
 providing a body having at least one groove, the groove having walls that taper outwardly from a bottom of the groove to the upper support surface.    
   
   
       33 . The method of  claim 32 , wherein the outwardly taping walls of the groove form an enclosed angle less than about three degrees.  
   
   
       34 . The method of  claim 29 , wherein the step of cladding the heater element further comprises: 
 wrapping a conformable sheet of cladding material around the heater element.    
   
   
       35 . The method of  claim 29 , wherein the step of cladding the heater element further comprises: 
 drawing a tubing of the cladding material having a larger diameter than the heating element through a die and swaging the tubing around the heater element.    
   
   
       36 . The method of  claim 29 , wherein the step of cladding the heater element further comprises: 
 cladding the heater element with a material comprising an aluminum alloy in the range of from about aluminum 1100 to about aluminum 3000-100 series.    
   
   
       37 . The method of  claim 29 , wherein the step of cladding the heater element further comprises: 
 removing substantially all air between the cladding and the heater element to form an integral bond between the heater element and the cladding.    
   
   
       38 . The method of  claim 29 , wherein the step of cladding the heater element further comprises: 
 annealing the cladding material.    
   
   
       39 . The method of  claim 29 , wherein the step of inserting the clad heater element into the groove further comprises: 
 removing a native oxide layer from surfaces of the groove prior to inserting the clad heater element.    
   
   
       40 . The method of  claim 29 , wherein the step of inserting the clad heater element into the groove further comprises: 
 working the cladding to provide integral contact between the cladding and the body.    
   
   
       41 . The method of  claim 29 , wherein the step of inserting the clad heater element into the groove further comprises: 
 press-fitting the clad heater element into the groove.    
   
   
       42 . The method of  claim 29 , wherein at least a bottom portion of the groove has a diameter which lies between the diameter of the clad heater element prior to insertion into the groove and the diameter of the unclad heater element.  
   
   
       43 . The method of  claim 29 , wherein the step of providing a body having at least one groove further comprises: 
 roughening a bottom surface of the groove.    
   
   
       44 . The method of  claim 29 , wherein the step of capping the groove further comprises: 
 welding the cap in place.    
   
   
       45 . The method of  claim 29 , wherein the step of capping the groove further comprises: 
 forging the cap in place.    
   
   
       46 . The method of  claim 29 , wherein the step of capping the groove further comprises: 
 forming a seal between the heater element and an atmosphere outside of the substrate support.