Plasma etching chamber and method for manufacturing photomask using the same

Abstract

A plasma etching chamber of a plasma etching apparatus used in an etching process for manufacturing a photomask and a method for manufacturing a photomask using the same. The plasma etching chamber includes an electrode having a supporting surface for supporting a photomask substrate and a top surface surrounding the supporting surface, a heat transfer element installed along a peripheral edge of the supporting surface, and a heater for supplying heat to the heat transfer element. In the method for manufacturing a photomask, a shading layer is formed on a transparent substrate. A photoresist layer pattern is formed on the shading layer to partially expose the shading layer. The shading layer is etched to form a shading layer pattern, using plasma with the photoresist layer pattern as an etching mask, under a state in which the temperature of at least one portion of the peripheral edge of the transparent substrate is maintained higher than a temperature at a center of the transparent substrate.

What is claimed is:  
     
         1 . A plasma etching chamber comprising: 
 an electrode including 
 a supporting surface for supporting a photomask substrate, and  
 a top surface surrounding the supporting surface;  
   a heat transfer element installed along a peripheral edge of the supporting surface; and    a heater for supplying heat to the heat transfer element.    
     
     
         2 . The plasma etching chamber of  claim 1 , wherein the heat transfer element is integrally formed within the electrode.  
     
     
         3 . The plasma etching chamber of  claim 2 , wherein the heat transfer element is partially exposed along the peripheral edge of the supporting surface and the top surface of the electrode.  
     
     
         4 . The plasma etching chamber of  claim 2 , wherein a horizontal plane of the supporting surface is stepped down from a horizontal plane of the top surface, and the electrode further comprises a side wall extending between the top surface and the supporting surface, and wherein the heat transfer element is partially exposed along the peripheral edge of the supporting surface, the side wall, and the top surface of the electrode.  
     
     
         5 . The plasma etching chamber of  claim 2 , wherein the heat transfer element is partially exposed only along the peripheral edge of the supporting surface.  
     
     
         6 . The plasma etching chamber of  claim 1 , wherein the heat transfer element is formed of metal.  
     
     
         7 . The plasma etching chamber of  claim 1 , wherein the heat transfer element comprises a pipe line, and a heat transfer fluid flowing through the pipe line for heating the pipe line.  
     
     
         8 . The plasma etching chamber of  claim 7 , wherein the heat transfer fluid is one selected from oil and gas.  
     
     
         9 . The plasma etching chamber of  claim 1 , wherein the heat transfer element is a heating coil.  
     
     
         10 . The plasma etching chamber of  claim 1 , wherein the electrode and supporting surface face upwardly toward an upper portion of the plasma etching chamber.  
     
     
         11 . A plasma etching chamber comprising: 
 an electrode including 
 a supporting surface for supporting a photomask substrate, and  
 a top surface surrounding the supporting surface;  
   a chucking pad arranged below the electrode, the chucking pad having a contact surface in contact with corner portions of the photomask substrate for fixing the photomask substrate supported by the supporting surface;    a heat transfer element installed within the chucking pad to heat the corner portions of the photomask substrate; and    a heater for supplying heat to the heat transfer element.    
     
     
         12 . The plasma etching chamber of  claim 11 , wherein the heat transfer element is installed within the contact surface of the chucking pad.  
     
     
         13 . The plasma etching chamber of  claim 12 , wherein the heat transfer element is comprised of metal.  
     
     
         14 . The plasma etching chamber of  claim 12 , wherein the heat transfer element is comprised of a heating coil.  
     
     
         15 . The plasma etching chamber of  claim 12 , wherein the electrode and the supporting surface face downwardly toward a lower portion of the plasma etching chamber.  
     
     
         16 . A method for manufacturing a photomask comprising: 
 forming a shading layer on a transparent substrate;    forming a photoresist layer pattern on the shading layer so as to partially expose the shading layer;    etching the shading layer using plasma to form a shading layer pattern, and using the photoresist layer pattern as an etching mask; and    heating the transparent substrate, while etching, such that a temperature of at least one portion of a peripheral edge of the transparent substrate is maintained higher than a temperature of a center portion of the transparent substrate.    
     
     
         17 . The method of  claim 16 , further comprising providing a transparent substrate formed of quartz.  
     
     
         18 . The method of  claim 16 , further comprising providing a shading layer formed of chrome.  
     
     
         19 . The method of  claim 16 , further comprising providing a photoresist layer pattern formed of an electron-beam photoresist.  
     
     
         20 . The method of  claim 16 , wherein during the etching of the shading layer, the heating comprises heating a peripheral edge of the transparent substrate in order to maintain the temperature of the peripheral edge of the transparent substrate higher than the temperature of the center of the transparent substrate.  
     
     
         21 . The method of  claim 16 , wherein during the etching of the shading layer, the heating comprises heating only a bottom edge of the transparent substrate in order to heat the peripheral edge of the transparent substrate.  
     
     
         22 . The method of  claim 16 , wherein during the etching of the shading layer, the heating comprises heating a bottom edge and side walls of the transparent substrate in order to the heat the peripheral edge of the transparent substrate.  
     
     
         23 . The method of  claim 16 , wherein during the etching the shading layer, corner portions of the peripheral edge of the transparent substrate are heated in order to maintain the corners of the transparent substrate at a temperature higher than the temperature of the center of the transparent substrate.