Heat transfer assembly

Abstract

A heat transfer assembly having a heat spreading member sandwiched between a heat source and a heat sink is disclosed. The heat sink, the heat spreading member, and the heat source are pressed against the bottom of a substrate support plate by a bias member.

1 . A heat transfer assembly for a substrate support in a substrate processing system, comprising: 
 a first contact plate;    a second contact plate disposed below the first contact plate; and    a heat spreading member sandwiched between the first and the second contact plates, wherein the heat transfer assembly is configured to be disposed between a heat source and a heat sink in a substrate support and to reduce temperature non-uniformity caused by features formed in the substrate support, and wherein the first and second contact plates reduce heat flux through the heat transfer assembly.    
   
   
       2 . The heat transfer assembly of  claim 1 , wherein the heat spreading member has a higher thermal conductivity than the first and second contact plates.  
   
   
       3 . The heat transfer assembly of  claim 1 , wherein the heat spreading member is between about 3-12 millimeters thick.  
   
   
       4 . The heat transfer assembly of  claim 1 , wherein the first and the second contact plates are between about 3-12 millimeters thick.  
   
   
       5 . The heat transfer assembly of  claim 1 , wherein the first and second contact plates each comprise one smooth contact surface and one embossed contact surface.  
   
   
       6 . The heat transfer assembly of  claim 5 , wherein the embossed contact surface comprises an area that is about 5 to 50% of the surface area of the smooth contact surface.  
   
   
       7 . The heat transfer assembly of  claim 5 , wherein embossment in a first region of the embossed contact surface differs from embossment in at least one other region of the embossed contact surface.  
   
   
       8 . The heat transfer assembly of  claim 5 , wherein the embossed contact surface of the first contact plate contacts an upper surface of the heat spreader member and a the smooth contact surface of the second contact plate contacts a bottom surface of the heat spreader member.  
   
   
       9 . The heat transfer assembly of  claim 1 , wherein the heat spreading member is formed of a material selected from the group consisting of aluminum nitride (AlN) and copper (Cu).  
   
   
       10 . The heat transfer assembly of  claim 1 , wherein the first and second contact plates are formed of a material selected from the group consisting of titanium (Ti) and an alloy comprising iron (Fe), nickel (Ni) and cobalt (Co).  
   
   
       11 . The heat transfer assembly of  claim 1 , wherein a thermally conductive sheet is disposed in least one of the following locations: adjacent a top surface of the first contact plate, immediately between the first contact plate and the heat spreader member, immediately between the heat spreader member and the second contact plate, or adjacent a lower surface of the second contact plate.  
   
   
       12 . The heat transfer assembly of  claim 11 , wherein the thermally conductive sheet is formed of a material selected from the group consisting of graphite and aluminum.  
   
   
       13 . The heat transfer assembly of  claim 11 , wherein the thermally conductive sheet is between about 1-5 micrometers thick.  
   
   
       14 . Apparatus for processing a semiconductor substrate, comprising: 
 a process chamber; and    a substrate support disposed in the process chamber comprising a heat spreading member sandwiched between a first contact plate and a second contact plate, wherein the first contact plate is thermally coupled to a heat source and the second contact plate is thermally coupled to a heat sink, wherein the heat spreading member is configured to reduce temperature non-uniformity caused by features formed in the substrate support, and wherein the first and second contact plates reduce heat flux from the heat source to the heat sink.    
   
   
       15 . The apparatus of  claim 14 , wherein the heat source is an embedded heater.  
   
   
       16 . The apparatus of  claim 15 , wherein the embedded heater is a detachable heater that is thermally coupled to a substrate support plate of the substrate support.  
   
   
       17 . The apparatus of  claim 14 , wherein the first and second contact plates each comprise one smooth contact surface and one embossed contact surface, wherein the embossed contact surface of the first contact plate contacts an upper surface of the heat spreader member and a the smooth contact surface of the second contact plate contacts a bottom surface of the heat spreader member.  
   
   
       18 . The apparatus of  claim 17 , wherein embossment in a first region of the embossed contact surface differs from embossment in at least one other region of the embossed contact surface.  
   
   
       19 . The apparatus of  claim 14 , wherein the heat spreading member is formed of a material selected from the group consisting of aluminum nitride (AlN) and copper (Cu).  
   
   
       20 . The apparatus of  claim 14 , wherein the first and second contact plates are formed of a material selected from the group consisting of titanium (Ti) and an alloy comprising iron (Fe), nickel (Ni) and cobalt (Co).  
   
   
       21 . The apparatus of  claim 14 , further comprising at least one bias member that engages and improves thermal coupling between a substrate support plate, the heat source, the heat transfer assembly, and the heat sink.  
   
   
       22 . The apparatus of  claim 21 , wherein each bias member exerts an expanding elastic force and is disposed in the heat sink or a base member coupled to the heat sink.  
   
   
       23 . The apparatus of  claim 14 , wherein a thermally conductive sheet is disposed immediately between at least one of the following: a bottom surface of a substrate support plate and the heat source, a bottom surface of the heat source and a top surface of the first contact plate, a bottom surface of the first contact plate and a top surface of the heat spreader member, a bottom surface of the heat spreader member and a top surface of the second contact plate, or a bottom surface of the second contact plate and a top surface of a heat sink.  
   
   
       24 . The apparatus of  claim 23 , wherein the thermally conductive sheet is formed of a material selected from the group consisting of graphite and aluminum and is between about 1-5 micrometers thick.  
   
   
       25 . A substrate support, comprising: 
 a heat source disposed beneath a support surface of the substrate support;    a heat sink disposed beneath the heat source; and    a heat transfer assembly thermally coupling the heat source to the heat sink, the heat transfer assembly comprising: 
 a heat spreading member sandwiched between a first contact plate and a second contact plate, wherein the first and second contact plates reduce heat flux through the heat transfer assembly.