Rapid heating and cooling of workpiece chucks

Abstract

A workpiece support or chuck that rapidly heats and cools a semiconductor workpiece is disclosed. A heat source and a cooling source, maintained at different temperatures, alternately communicate with the chuck. In one embodiment, the heat source and cooling source alternately provide relatively “hot” and “cold” heat transfer fluids to fluid channels within the workpiece chuck. Accordingly, a semiconductor workpiece in contact with the chuck rapidly heats to the temperature of the hot fluid, or rapidly cools to the temperature of the cold fluid, depending upon which fluid flowing through the chuck. In another embodiment, the heat source comprises a movable resistive heating block at a first temperature that is placed in contact with the chuck during heating, and is removed from the chuck while colder heat transfer fluid circulates within the chuck. Optionally, inert fluid can be provided to purge heat transfer fluid from the chuck channels between heating and cooling steps.

I claim:  
     
         1 . An apparatus for controlling the temperature of workpieces in a semiconductor processing reactor, comprising: 
 a support having fluid channels therein;    a cold fluid source communicating with the fluid channels via a first supply line, the cold fluid source configured to maintain a cold fluid maintained at a first temperature;    a heat source maintained at a second temperature, the second temperature being higher than the first temperature; and    a mechanism for conductively transferring heat from the heat source to the support.    
     
     
         2 . The apparatus of  claim 1 , wherein the heat source comprises a hot fluid source configured to maintain a hot fluid at the second temperature, and the mechanism comprises a second supply line in fluid communication with the hot fluid source and channels in the support.  
     
     
         3 . The apparatus of  claim 2 , wherein the first supply line and the second supply line are in fluid communication with the same fluid channels in the support.  
     
     
         4 . The apparatus of  claim 3 , further comprising a three-way switching valve controlling flow from the cold fluid source and the hot fluid source to the fluid channels.  
     
     
         5 . The apparatus of  claim 3 , wherein the first supply line and the second supply line overlap in a common supply line section downstream of the three-way switching valve.  
     
     
         6 . The apparatus of  claim 5 , further comprising a purge line connected to the common supply line section for purging heat transfer fluid from the fluid channels.  
     
     
         7 . The apparatus of  claim 3 , further comprising a first return line in fluid communication with a downstream end of the fluid channels and with the cold fluid source, and a second return line in fluid communication with the downstream end of the fluid channels and with the hot fluid source.  
     
     
         8 . The apparatus of  claim 7 , further comprising a three-way switching valve controlling flow from the fluid channels to the cold fluid source and the hot fluid source.  
     
     
         9 . The apparatus of  claim 3 , wherein the hot fluid and the cold fluid have the same chemical composition.  
     
     
         10 . The apparatus of  claim 2 , wherein the fluid channels occupy at least 50% of a volume of the support.  
     
     
         11 . The apparatus of  claim 1 , further comprising a purge line connected to the fluid channels for purging heat transfer fluid therefrom.  
     
     
         12 . The apparatus of  claim 1 , wherein the heat source comprises a heater block, and the mechanism comprises a mechanical lift placing the heater block in conductive contact with the support.  
     
     
         13 . The apparatus of  claim 12 , wherein the heat source is resistively heated.  
     
     
         14 . The apparatus of  claim 10 , wherein the heat source is heated by circulation of hot fluid therethrough.  
     
     
         15 . The apparatus of  claim 1 , wherein the first temperature is selected to maintain a workpiece supported upon the support at less than about 150° C., and the second temperature is selected to maintain the workpiece at between about 150° C. and 300° C.  
     
     
         16 . The apparatus of  claim 1 , wherein the semiconductor processing reactor comprises a photoresist asher.