Apparatus and method for reducing electrical noise in a thermally controlled chuck

Abstract

A system and method for controlling temperature of a workpiece such as a semiconductor wafer and the chuck supporting the wafer are described. The system includes a heat exchanger used in controlling temperature of a temperature control fluid. A first fluid carrying path carries the temperature control fluid from the heat exchanger to an outlet, the outlet being connectable to the workpiece chuck to carry the temperature control fluid to the workpiece chuck. A second fluid carrying path carries the temperature control fluid from an inlet to the heat exchanger, the inlet being connectable to the workpiece chuck to carry the temperature control fluid from the workpiece chuck to the temperature control system. A dual-flow rate technique is employed such that, when the chuck temperature is in transition, the temperature control fluid is circulated at a relatively high flow rate such that temperature transition of the chuck can be realized at a fast rate. When the temperature of the chuck is being maintained at a set point temperature, the flow rate of the fluid can be reduced such that electrical noise introduced by the motion of the fluid, such as by the triboelectric effect, can be reduced. A capillary tube can be connected between the first fluid carrying path and the second fluid carrying path. First and second valves can be connected in the first and second fluid carrying paths to prevent the flow of fluid into the chuck when the chuck is at high temperature such that motion induced by flash boiling of the fluid is eliminated.

1 . A temperature control system for a workpiece chuck, comprising: 
 a temperature control device for controlling temperature of a temperature control fluid;    a fluid inlet and a fluid outlet, the temperature control fluid being carried to and from the chuck via the fluid inlet and the fluid outlet; and    a controller for controlling the temperature control device, the controller controlling a flow rate of the temperature control fluid through the chuck, such that the flow rate of the temperature control fluid through the chuck when the temperature of the chuck is in transition is higher than the flow rate of the temperature control fluid through the chuck when the temperature of the chuck is being maintained at a set point temperature.    
   
   
       2 . The temperature control system of  claim 1 , further comprising a flow controlling device being controllable to change the flow rate of the temperature control fluid.  
   
   
       3 . The temperature control system of  claim 2 , further comprising: 
 a first fluid carrying path connected to one of the inlet and the outlet; and    a second fluid carrying path connected to the other of the inlet and the outlet;    wherein the flow controlling device is connected in one of the first and second fluid carrying paths.    
   
   
       4 . The temperature control system of  claim 3 , wherein the flow controlling device comprises: 
 a fixed-orifice flow reducing device in one of the first and second fluid carrying paths; and    a controllable valve in parallel with the fixed-orifice flow reducing device.    
   
   
       5 . The temperature control system of  claim 4 , wherein the controller controls the controllable valve to be open when temperature in the chuck is in transition and closed when the temperature in the chuck is to be maintained at a desired set point.  
   
   
       6 . The temperature control system of  claim 3 , wherein the flow controlling device comprises: 
 a first controllable valve connected in one of the first and second fluid carrying paths; and    a second controllable valve connected in the one of the first and second fluid carrying paths in parallel with the first controllable valve.    
   
   
       7 . The temperature control system of  claim 6 , wherein the controller controls the first and second controllable valves such that one of the first and second controllable valves is open when temperature in the chuck is in transition and closed when the temperature in the chuck is to be maintained at a desired set point.  
   
   
       8 . The temperature control system of  claim 1 , further comprising: 
 a first fluid carrying path connected to one of the inlet and the outlet;    a second fluid carrying path connected to the other of the inlet and the outlet; and    a capillary tube connected between the first and second fluid carrying paths.    
   
   
       9 . The temperature control system of  claim 8 , wherein the capillary tube is adapted to balance pressures in the first and second fluid carrying paths.  
   
   
       10 . The temperature control system of  claim 8 , further comprising a first valve in the first fluid carrying path and a second valve in the second fluid carrying path.  
   
   
       11 . The temperature control system of  claim 10 , wherein the first and second valves are closed when the temperature of the chuck is above a predetermined temperature such that the temperature control fluid is prevented from flowing into the chuck.  
   
   
       12 . The temperature control system of  claim 11 , wherein the predetermined temperature is above a boiling point of the temperature control fluid.  
   
   
       13 . The temperature control system of  claim 1 , further comprising: 
 a first fluid carrying path connected to one of the inlet and the outlet;    a second fluid carrying path connected to the other of the inlet and the outlet;    a first valve in the first fluid carrying path; and    a second valve in the second fluid carrying path.    
   
   
       14 . The temperature control system of  claim 13 , wherein the first and second valves are closed when the temperature of the chuck is above a predetermined temperature such that the temperature control fluid is prevented from flowing into the chuck.  
   
   
       15 . The temperature control system of  claim 14 , wherein the predetermined temperature is above a boiling point of the temperature control fluid.  
   
   
       16 . The temperature control system of  claim 1 , wherein the controller controls the temperature control device such that, when a temperature of the chuck is above a predetermined temperature, the temperature control fluid is prevented from entering the chuck.  
   
   
       17 . The temperature control system of  claim 16 , wherein the predetermined temperature is above a boiling temperature of the temperature control fluid.  
   
   
       18 . A temperature control system for a workpiece chuck, comprising: 
 a temperature control device for controlling temperature of a temperature control fluid;    a fluid inlet and a fluid outlet, the temperature control fluid being carried to and from the chuck via the fluid inlet and the fluid outlet; and    a controller for controlling the temperature control device such that, when a temperature of the chuck is above a predetermined temperature, the temperature control fluid is prevented from entering the chuck.    
   
   
       19 . The temperature control system of  claim 18 , wherein the predetermined temperature is above a boiling temperature of the temperature control fluid.  
   
   
       20 . The temperature control system of  claim 18 , further comprising: 
 a first fluid carrying path connected to one of the inlet and the outlet;    a second fluid carrying path connected to the other of the inlet and the outlet;    a first valve in the first fluid carrying path; and    a second valve in the second fluid carrying path.    
   
   
       21 . The temperature control system of  claim 20 , wherein the first and second valves are closed when the temperature of the chuck is above a predetermined temperature such that the temperature control fluid is prevented from flowing into the chuck.  
   
   
       22 . The temperature control system of  claim 21 , wherein the predetermined temperature is above a boiling point of the temperature control fluid.  
   
   
       23 . The temperature control system of  claim 18 , further comprising: 
 a first fluid carrying path connected to one of the inlet and the outlet;    a second fluid carrying path connected to the other of the inlet and the outlet; and    a capillary tube connected between the first and second fluid carrying paths.    
   
   
       24 . The temperature control system of  claim 23 , wherein the capillary tube is adapted to balance pressures in the first and second fluid carrying paths.  
   
   
       25 . The temperature control system of  claim 23 , further comprising a first valve in the first fluid carrying path and a second valve in the second fluid carrying path.  
   
   
       26 . The temperature control system of  claim 25 , wherein the first and second valves are closed when the temperature of the chuck is above a predetermined temperature such that the temperature control fluid is prevented from flowing into the chuck.  
   
   
       27 . The temperature control system of  claim 26 , wherein the predetermined temperature is above a boiling point of the temperature control fluid.  
   
   
       28 . The temperature control system of  claim 1 , wherein: 
 the controller controls a flow rate of the temperature control fluid through the chuck, such that the flow rate of the temperature control fluid through the chuck when the temperature of the chuck is in transition is higher than the flow rate of the temperature control fluid through the chuck when the temperature of the chuck is being maintained at a set point temperature; and    the system further comprises a flow controlling device being controllable to change the flow rate of the temperature control fluid.    
   
   
       29 . The temperature control system of  claim 28 , further comprising: 
 a first fluid carrying path connected to one of the inlet and the outlet; and    a second fluid carrying path connected to the other of the inlet and the outlet;    wherein the flow controlling device is connected in one of the first and second fluid carrying paths.    
   
   
       30 . The temperature control system of  claim 29 , wherein the flow controlling device comprises: 
 a fixed-orifice flow reducing device in one of the first and second fluid carrying paths; and    a controllable valve in parallel with the fixed-orifice flow reducing device.    
   
   
       31 . The temperature control system of  claim 30 , wherein the controller controls the controllable valve to be open when temperature in the chuck is in transition and closed when the temperature in the chuck is to be maintained at a desired set point.  
   
   
       32 . The temperature control system of  claim 29 , wherein the flow controlling device comprises: 
 a first controllable valve connected in one of the first and second fluid carrying paths; and    a second controllable valve connected in the one of the first and second fluid carrying paths in parallel with the first controllable valve.    
   
   
       33 . The temperature control system of  claim 32 , wherein the controller controls the first and second controllable valves such that one of the first and second controllable valves is open when temperature in the chuck is in transition and closed when the temperature in the chuck is to be maintained at a desired set point.  
   
   
       34 . A temperature control system for a workpiece chuck, comprising: 
 a temperature control device for controlling temperature of a temperature control fluid;    a fluid inlet and a fluid outlet, the temperature control fluid being carried to and from the chuck via the fluid inlet and the fluid outlet;    a first fluid carrying path connected to one of the inlet and the outlet;    a second fluid carrying path connected to the other of the inlet and the outlet;    a controller for controlling the temperature control device, the controller (i) controlling a flow rate of the temperature control fluid through the chuck, such that the flow rate of the temperature control fluid through the chuck when the temperature of the chuck is in transition is higher than the flow rate of the temperature control fluid through the chuck when the temperature of the chuck is being maintained at a set point temperature, and (ii) controlling the temperature control device such that, when a temperature of the chuck is above a predetermined temperature, the temperature control fluid is prevented from entering the chuck; and    a flow controlling device being controllable by the controller to change the flow rate of the temperature control fluid.    
   
   
       35 . The temperature control system of  claim 34 , wherein the flow controlling device is connected in one of the first and second fluid carrying paths.  
   
   
       36 . The temperature control system of  claim 35 , wherein the flow controlling device comprises: 
 a fixed-orifice flow reducing device in one of the first and second fluid carrying paths; and    a controllable valve in parallel with the fixed-orifice flow reducing device.    
   
   
       37 . The temperature control system of  claim 36 , wherein the controller controls the controllable valve to be open when temperature in the chuck is in transition and closed when the temperature in the chuck is to be maintained at a desired set point.  
   
   
       38 . The temperature control system of  claim 35 , wherein the flow controlling device comprises: 
 a first controllable valve connected in one of the first and second fluid carrying paths; and    a second controllable valve connected in the one of the first and second fluid carrying paths in parallel with the first controllable valve.    
   
   
       39 . The temperature control system of  claim 38 , wherein the controller controls the first and second controllable valves such that one of the first and second controllable valves is open when temperature in the chuck is in transition and closed when the temperature in the chuck is to be maintained at a desired set point.  
   
   
       40 . The temperature control system of  claim 34 , further comprising a capillary tube connected between the first and second fluid carrying paths.  
   
   
       41 . The temperature control system of  claim 40 , wherein the capillary tube is adapted to balance pressures in the first and second fluid carrying paths.  
   
   
       42 . The temperature control system of  claim 34 , further comprising: 
 a first valve in the first fluid carrying path; and    a second valve in the second fluid carrying path.    
   
   
       43 . The temperature control system of  claim 42 , wherein the first and second valves are closed when the temperature of the chuck is above a predetermined temperature such that the temperature control fluid is prevented from flowing into the chuck.  
   
   
       44 . The temperature control system of  claim 43 , wherein the predetermined temperature is above a boiling point of the temperature control fluid.  
   
   
       45 . A method of controlling temperature in a workpiece chuck, comprising: 
 controlling temperature of a temperature control fluid with a temperature control device;    carrying the temperature control fluid to and from the chuck via a fluid inlet and a fluid outlet; and    providing a controller for controlling the temperature control device, the controller controlling a flow rate of the temperature control fluid through the chuck, such that the flow rate of the temperature control fluid through the chuck when the temperature of the chuck is in transition is higher than the flow rate of the temperature control fluid through the chuck when the temperature of the chuck is being maintained at a set point temperature.    
   
   
       46 . The method of  claim 45 , further comprising providing a flow controlling device being controllable to change the flow rate of the temperature control fluid.  
   
   
       47 . The method of  claim 46 , further comprising: 
 connecting a first fluid carrying path to one of the inlet and the outlet; and    connecting a second fluid carrying path to the other of the inlet and the outlet; and    connecting the flow controlling device in one of the first and second fluid carrying paths.    
   
   
       48 . The method of  claim 47 , wherein the flow controlling device comprises: 
 a fixed-orifice flow reducing device in one of the first and second fluid carrying paths; and    a controllable valve in parallel with the fixed-orifice flow reducing device.    
   
   
       49 . The method of  claim 48 , wherein the controller controls the controllable valve to be open when temperature in the chuck is in transition and closed when the temperature in the chuck is to be maintained at a desired set point.  
   
   
       50 . The method of  claim 47 , wherein the flow controlling device comprises: 
 a first controllable valve connected in one of the first and second fluid carrying paths; and    a second controllable valve connected in the one of the first and second fluid carrying paths in parallel with the first controllable valve.    
   
   
       51 . The method of  claim 50 , wherein the controller controls the first and second controllable valves such that one of the first and second controllable valves is open when temperature in the chuck is in transition and closed when the temperature in the chuck is to be maintained at a desired set point.  
   
   
       52 . The method of  claim 45 , further comprising: 
 connecting a first fluid carrying path to one of the inlet and the outlet;    connecting a second fluid carrying path to the other of the inlet and the outlet; and    connecting a capillary tube between the first and second fluid carrying paths.    
   
   
       53 . The method of  claim 52 , wherein the capillary tube is adapted to balance pressures in the first and second fluid carrying paths.  
   
   
       54 . The method of  claim 52 , further comprising providing a first valve in the first fluid carrying path and a second valve in the second fluid carrying path.  
   
   
       55 . The method of  claim 54 , wherein the first and second valves are closed when the temperature of the chuck is above a predetermined temperature such that the temperature control fluid is prevented from flowing into the chuck.  
   
   
       56 . The method of  claim 55 , wherein the predetermined temperature is above a boiling point of the temperature control fluid;  
   
   
       57 . The method of  claim 45 , further comprising: 
 connecting a first fluid carrying path to one of the inlet and the outlet;    connecting a second fluid carrying path to the other of the inlet and the outlet;    providing a first valve in the first fluid carrying path; and    providing a second valve in the second fluid carrying path.    
   
   
       58 . The method of  claim 57 , wherein the first and second valves are closed when the temperature of the chuck is above a predetermined temperature such that the temperature control fluid is prevented from flowing into the chuck.  
   
   
       59 . The method of  claim 58 , wherein the predetermined temperature is above a boiling point of the temperature control fluid.  
   
   
       60 . The method of  claim 45 , wherein the controller controls the temperature control device such that, when a temperature of the chuck is above a predetermined temperature, the temperature control fluid is prevented from entering the chuck.  
   
   
       61 . The method of  claim 60 , wherein the predetermined temperature is above a boiling temperature of the temperature control fluid.  
   
   
       62 . A method of controlling temperature in a workpiece chuck, comprising: 
 controlling temperature of a temperature control fluid with a temperature control device;    carrying the temperature control fluid to and from the chuck via a fluid inlet and a fluid outlet; and    providing a controller for controlling the temperature control device such that, when a temperature of the chuck is above a predetermined temperature, the temperature control fluid is prevented from entering the chuck.    
   
   
       63 . The method of  claim 62 , wherein the predetermined temperature is above a boiling temperature of the temperature control fluid.  
   
   
       64 . The method of  claim 62 , further comprising: 
 connecting a first fluid carrying path to one of the inlet and the outlet;    connecting a second fluid carrying path to the other of the inlet and the outlet;    providing a first valve in the first fluid carrying path; and    providing a second valve in the second fluid carrying path.    
   
   
       65 . The method of  claim 64 , wherein the first and second valves are closed when the temperature of the chuck is above a predetermined temperature such that the temperature control fluid is prevented from flowing into the chuck.  
   
   
       66 . The method of  claim 65 , wherein the predetermined temperature is above a boiling point of the temperature control fluid.  
   
   
       67 . The method of  claim 62 , further comprising: 
 connecting a first fluid carrying path to one of the inlet and the outlet;    connecting a second fluid carrying path to the other of the inlet and the outlet; and    connecting a capillary tube between the first and second fluid carrying paths.    
   
   
       68 . The method of  claim 67 , wherein the capillary tube is adapted to balance pressures in the first and second fluid carrying paths.  
   
   
       69 . The method of  claim 67 , further comprising providing a first valve in the first fluid carrying path and a second valve in the second fluid carrying path.  
   
   
       70 . The method of  claim 69 , wherein the first and second valves are closed when the temperature of the chuck is above a predetermined temperature such that the temperature control fluid is prevented from flowing into the chuck.  
   
   
       71 . The method of  claim 70 , wherein the predetermined temperature is above a boiling point of the temperature control fluid.  
   
   
       72 . The method of  claim 62 , wherein: 
 the controller controls a flow rate of the temperature control fluid through the chuck, such that the flow rate of the temperature control fluid through the chuck when the temperature of the chuck is in transition is higher than the flow rate of the temperature control fluid through the chuck when the temperature of the chuck is being maintained at a set point temperature; and    a flow controlling device is controllable by the controller to change the flow rate of the temperature control fluid.    
   
   
       73 . The method of  claim 72 , further comprising: 
 connecting a first fluid carrying path to one of the inlet and the outlet; and    connecting a second fluid carrying path to the other of the inlet and the outlet;    wherein the flow controlling device is connected in one of the first and second fluid carrying paths.    
   
   
       74 . The method of  claim 73 , wherein the flow controlling device comprises: 
 a fixed-orifice flow reducing device in one of the first and second fluid carrying paths; and    a controllable valve in parallel with the fixed-orifice flow reducing device.    
   
   
       75 . The method of  claim 74 , wherein the controller controls the controllable valve to be open when temperature in the chuck is in transition and closed when the temperature in the chuck is to be maintained at a desired set point.  
   
   
       76 . The method of  claim 73 , wherein the flow controlling device comprises: 
 a first controllable valve connected in one of the first and second fluid carrying paths; and    a second controllable valve connected in the one of the first and second fluid carrying paths in parallel with the first controllable valve.    
   
   
       77 . The method of  claim 76 , wherein the controller controls the first and second controllable valves such that one of the first and second controllable valves is open when temperature in the chuck is in transition and closed when the temperature in the chuck is to be maintained at a desired set point.  
   
   
       78 . A method of controlling temperature in a workpiece chuck, comprising: 
 controlling temperature of a temperature control fluid with a temperature control device;    carrying the temperature control fluid to and from the chuck via a fluid inlet and a fluid outlet;    connecting a first fluid carrying path to one of the inlet and the outlet;    connecting a second fluid carrying path to the other of the inlet and the outlet;    providing a controller for controlling the temperature control device, the controller (i) controlling a flow rate of the temperature control fluid through the chuck, such that the flow rate of the temperature control fluid through the chuck when the temperature of the chuck is in transition is higher than the flow rate of the temperature control fluid through the chuck when the temperature of the chuck is being maintained at a set point temperature, and (ii) controlling the temperature control device such that, when a temperature of the chuck is above a predetermined temperature, the temperature control fluid is prevented from entering the chuck; and    providing a flow controlling device being controllable by the controller to change the flow rate of the temperature control fluid.    
   
   
       79 . The method of  claim 78 , wherein the flow controlling device is connected in one of the first and second fluid carrying paths.  
   
   
       80 . The method of  claim 79 , wherein the flow controlling device comprises: 
 a fixed-orifice flow reducing device in one of the first and second fluid carrying paths; and    a controllable valve in parallel with the fixed-orifice flow reducing device.    
   
   
       81 . The method of  claim 80 , wherein the controller controls the controllable valve to be open when temperature in the chuck is in transition and closed when the temperature in the chuck is to be maintained at a desired set point.  
   
   
       82 . The method of  claim 79 , wherein the flow controlling device comprises: 
 a first controllable valve connected in one of the first and second fluid carrying paths; and    a second controllable valve connected in the one of the first and second fluid carrying paths in parallel with the first controllable valve.    
   
   
       83 . The method of  claim 82 , wherein the controller controls the first and second controllable valves such that one of the first and second controllable valves is open when temperature in the chuck is in transition and closed when the temperature in the chuck is to be maintained at a desired set point.  
   
   
       84 . The method of  claim 78 , further comprising connecting a capillary tube between the first and second fluid carrying paths.  
   
   
       85 . The method of  claim 84 , wherein the capillary tube is adapted to balance pressures in the first and second fluid carrying paths.  
   
   
       86 . The method of  claim 78 , further comprising: 
 providing a first valve in the first fluid carrying path; and    providing a second valve in the second fluid carrying path.    
   
   
       87 . The method of  claim 86 , wherein the first and second valves are closed when the temperature of the chuck is above a predetermined temperature such that the temperature control fluid is prevented from flowing into the chuck.  
   
   
       88 . The method of  claim 87 , wherein the predetermined temperature is above a boiling point of the temperature control fluid.