Semiconductor processing temperature control

Abstract

A temperature control system having a re-circulation loop that uses valves to selectively circulate a temperature control fluid through a cooling system, through a heating system, or through a through passage so as to controlling the temperature of the temperature control fluid, which, in turn, controls the temperature of a target. A temperature sensor monitors the target's temperature. A controller controls valve operation in response to the temperature measured by the temperature sensor to obtain a predetermined target temperature. Beneficially, the controller controls the target's temperature according to a predetermined temperature profile. Continuous etching along a predetermined temperature profile is possible.

1 - 22 . (canceled)  
   
   
       23 . A method of forming a contact comprising: 
 providing a silicon layer with a copper plug embedded therein;    providing a metal hardmask over the copper plug;    depositing a resist layer over the metal hardmask;    a first etch step for etching a first opening in the resist layer at a first temperature; and    a second etch step for etching the metal hardmask at a second temperature wherein the same etchant is used for the first etch step and the second etch step.    
   
   
       24 . A method of forming a contact according to  claim 23 , wherein the first temperature and the second temperature are different.  
   
   
       25 . A method of forming a contact according to  claim 23 , wherein the first and second etch steps are continuously performed in one vessel.  
   
   
       26 . A method of forming a contact according to  claim 23 , further comprising 
 completely removing the resist layer during the second etch step.    
   
   
       27 . A method of forming a contact according to  claim 23 , further comprising sequentially providing a first nitride layer, a first polyimide layer, a second nitride layer, a second polyimide layer, before providing said metal hardmask.  
   
   
       28 . A method of forming a contact according to  claim 27 , further comprising sequentially and continuously etching the second polyimide layer, the second nitride layer, the first polyimide layer and the first nitride layer to form an opening to expose said copper plug.  
   
   
       29 . A method of forming a contact according to  claim 27 , wherein the first polyimide layer and the second polyimide layer are etched at said first temperature.  
   
   
       30 . A method of forming a contact according to  claim 28 , wherein the first nitride layer and second nitride layer are etched at said second temperature.  
   
   
       31 . A method of forming a contact according to  claim 29 , wherein the second polyimide layer, the second nitride layer, the first polyimide layer and the first nitride layer are etched in the same vessel and using the same etchant.  
   
   
       32 . A method of forming a contact according to  claim 30 , further comprising electroplating copper in said opening.