Method and apparatus for controlling spatial temperature distribution

Abstract

A chuck for a plasma processor comprises a temperature-controlled base, a thermal insulator, a flat support, and a heater. The temperature-controlled base is controlled in operation a temperature below the desired temperature of a workpiece. The thermal insulator is disposed over at least a portion of the temperature-controlled base. The flat support holds a workpiece and is disposed over the thermal insulator. A heater is embedded within the flat support and/or mounted to an underside of the flat support. The heater includes a plurality of heating elements that heat a plurality of corresponding heating zones. The power supplied and/or temperature of each heating element is controlled independently. The heater and flat support have a combined temperature rate change of at least 1 ° C. per second.

1 . A chuck for a plasma processor comprising: 
 a temperature-controlled base having a temperature below the desired temperature of a workpiece;    a layer of thermal insulation material disposed over said base;    a flat support for holding said workpiece, said flat support disposed over said layer of thermal insulation material; and    a heater coupled to an underside of said flat support, said heater including a plurality of planar heating elements corresponding to a plurality of heating regions in said flat support,    wherein said heater has a temperature rate change of at least 1° C. per second.    
   
   
       2 . The chuck of  claim 1  wherein power applied to each planar heating element is controlled independently.  
   
   
       3 . The chuck of  claim 1  further comprising a thermal conductor disposed between said flat support and said workpiece.  
   
   
       4 . The chuck of  claim 1  wherein said temperature-controlled base is maintained at a constant temperature of less than 20° C.  
   
   
       5 . The chuck of  claim 1  further comprising a plurality of sensors corresponding with said plurality of heating regions, each sensor measuring and sending a signal representative of the temperature of its corresponding heating region.  
   
   
       6 . The chuck of  claim 5  further comprising a controller for receiving said signal from said sensor and for adjusting the power of each planar heating element based on a set point for each heating region.  
   
   
       7 . The chuck of  claim 1  wherein said heater includes a plurality of electrically resistive heaters.  
   
   
       8 . The chuck of  claim 1  wherein said heater includes a plurality of induction heaters.  
   
   
       9 . The chuck of  claim 1  wherein said heater includes a plurality of heating lamps.  
   
   
       10 . The chuck of  claim 1  wherein said heater includes a plurality of thermoelectric modules.  
   
   
       11 . The chuck of  claim 1  wherein said flat support includes an electrostatic chuck.  
   
   
       12 . A chuck for a plasma processor comprising: 
 a temperature-controlled base having a temperature below the desired temperature of a workpiece;    a layer of thermal insulation material disposed over said base;    a flat support for holding said workpiece, said flat support disposed over said layer of thermal insulation material; and    a heater embedded within said flat support, said heater including a plurality of planar heating elements corresponding to a plurality of heating regions in said flat support,    wherein the temperature of said heater and said flat support are adapted to be capable of change of at least 1° C. per second.    
   
   
       13 . The chuck of  claim 12  wherein the power of each planar heating element is controlled independently.  
   
   
       14 . The chuck of  claim 12  further comprising a thermal conductor disposed between said flat support and said workpiece.  
   
   
       15 . The chuck of  claim 12  wherein said temperature-controlled base is maintained at a constant temperature of less than 20° C.  
   
   
       16 . The chuck of  claim 12  further comprising a plurality of sensors corresponding with said plurality of heating regions, each sensor measuring and sending a signal representative of the temperature of its corresponding heating region.  
   
   
       17 . The chuck of  claim 16  further comprising a controller for receiving said signal from said sensor and for adjusting the power of each planar heating element based on a set point for each heating region.  
   
   
       18 . The chuck of  claim 16  wherein said heater includes a plurality of electrically resistive heaters.  
   
   
       19 . The chuck of  claim 16  wherein said heater includes a plurality of induction heaters.  
   
   
       20 . The chuck of  claim 16  wherein said heater includes a plurality of heating lamps.  
   
   
       21 . The chuck of  claim 16  wherein said heater includes a plurality of thermoelectric modules.  
   
   
       22 . The chuck of  claim 16  wherein a thickness of said flat support, a power density of said heater, and a thermal resistance of said layer of insulation material permit a temperature change in said flat support of at least 1° C. per second.  
   
   
       23 . The chuck of  claim 16  wherein said flat support includes an electrostatic chuck.  
   
   
       24 . A method for controlling the spatial temperature across a workpiece comprising: 
 providing a base maintained at a constant temperature, said constant temperature being below the temperature of the workpiece, said base having a layer of thermal insulation material mounted on top of said base;    holding the workpiece against a top face of a flat support having a plurality of spatial regions, said flat support mounted on top of said layer of thermal insulation material;    independently heating each spatial region of said flat support with a plurality of heaters mounted to an underside of said flat support; and    changing the temperature of at least one spatial region of said flat support during an etching process at a rate of at least 1° C. per second.    
   
   
       25 . The method of  claim 24  further comprising monitoring the temperature of said plurality of spatial regions with a sensor placed in each region.  
   
   
       26 . The method of  claim 25  further comprising adjusting the temperature of each spatial region based on said monitoring.  
   
   
       27 . The method of  claim 24  wherein said plurality of heaters includes a plurality of electrically resistive heaters.  
   
   
       28 . The method of  claim 24  wherein said plurality of heaters includes a plurality of induction heaters.  
   
   
       29 . The method of  claim 24  wherein said plurality of heaters includes a plurality of heating lamps.  
   
   
       30 . The method of  claim 24  wherein said plurality of heaters includes a plurality of thermoelectric modules.  
   
   
       31 . A method for controlling the spatial temperature across a workpiece comprising: 
 providing a base maintained at a constant temperature, said constant temperature being below the temperature of the workpiece, said base having a layer of thermal insulation material mounted on top of said base;    holding the workpiece against a top face of a flat support having a plurality of spatial regions, said flat support mounted on top of said layer of thermal insulation material;    independently heating each spatial region of said flat support with a plurality of heaters embedded within said flat support; and    changing the temperature of at least one spatial region of said flat support during an etching process at a rate of at least 1° C. per second.    
   
   
       32 . The method of  claim 31  further comprising monitoring the temperature of said plurality of spatial regions with a sensor placed in each region.  
   
   
       33 . The method of  claim 32  further comprising adjusting the temperature of each spatial region based on said monitoring.  
   
   
       34 . The method of  claim 31  wherein said plurality of heaters includes a plurality of electrically resistive heaters.  
   
   
       35 . The method of  claim 31  wherein said plurality of heaters includes a plurality of induction heaters.  
   
   
       36 . The method of  claim 31  wherein said plurality of heaters includes a plurality of heating lamps.  
   
   
       37 . The method of  claim 31  wherein said plurality of heaters includes a plurality of thermoelectric modules.  
   
   
       38 . An apparatus for controlling the spatial temperature across a workpiece comprising: 
 means for providing a base maintained at a constant temperature, said constant temperature being below the temperature of the workpiece, said base having a layer of thermal insulation material mounted on top of said base;    means for holding the workpiece against a top face of a flat support having a plurality of spatial regions, said flat support mounted on top of said layer of thermal insulation material;    means for independently heating each spatial region of said flat support with a plurality of heaters mounted to an underside of said flat support; and    means for changing the temperature of at least one spatial region of said flat support during an etching process at a rate of at least 1° C. per second.    
   
   
       39 . An apparatus for controlling the spatial temperature across a workpiece comprising: 
 means for providing a base maintained at a constant temperature, said constant temperature being below the temperature of the workpiece, said base having a layer of thermal insulation material mounted on top of said base;    means for holding the workpiece against a top face of a flat support having a plurality of spatial regions, said flat support mounted on top of said layer of thermal insulation material;    means for independently heating each spatial region of said flat support with a plurality of heaters embedded within said flat support; and    means for changing the temperature of at least one spatial region of said flat support during an etching process at a rate of at least 1° C. per second.