Photomask fabrication utilizing a carbon hard mask

Abstract

Methods for forming a photomask using a carbon hard mask are provided. In one embodiment, a method of forming a photomask includes etching a chromium layer through a patterned carbon hard mask layer in the presence of a plasma formed from a process gas containing chlorine and carbon monoxide.

1 . Computer-readable media containing instructions, that when executed by a controller cause a semiconductor processing system to perform an etch method on a substrate disposed in the system, the substrate having a carbon hard mask disposed over a chromium layer and a quartz layer, the method comprising: 
 flowing about 50 to about 1000 sccm of chlorine containing gas into a processing chamber of the system;    flowing about 10 to about 500 sccm of CO into the processing chamber;    forming a plasma of the process gas;    biasing the substrate with a power of less than 100 W; and    etching the chromium layer exposed through the patterned hard mask.    
     
     
         2 . The computer-readable media of  claim 1 , wherein the instructions, when executed by the controller, cause the method to further comprise: 
 flowing at least one of Cl 2 , BCl 3 , or HCl into the processing chamber.    
     
     
         3 . The computer-readable media of  claim 2 , wherein the instructions, when executed by the controller, cause the method to further comprise: 
 flowing about 300 sccm of Cl 2  into the processing chamber;    flowing about 150 sccm of CO into the processing chamber;    maintaining chamber pressure at around 3 mTorr;    applying a plasma source power at around 300 Watts; and    supplying a plasma bias power at around 8 Watts.    
     
     
         4 . The computer-readable media of  claim 2 , wherein the instructions, when executed by the controller, cause the method to further comprise: 
 flowing about 200 to about 400 sccm of Cl 2  into the processing chamber; and    flowing about 100 to about 300 sccm of CO into the processing chamber.    
     
     
         5 . The computer-readable media of  claim 1 , wherein the instructions, when executed by the controller, cause the method to further comprise: 
 pulsing the bias power.    
     
     
         6 . Computer-readable media containing instructions, that when executed by a controller cause a semiconductor processing system to perform an etch method on a substrate disposed in the system, the method comprising: 
 patterning a carbon hard mask layer on the substrate, the carbon hard mask layer disposed on a chromium layer having a underlying quartz layer, the patterning of the hard mask layer forming a hard mask on the chromium layer;    flowing about 200 to about 400 sccm of Cl 2  into the processing chamber;    flowing about 100 to about 300 sccm of CO into the processing chamber;    forming a plasma of the process gas in the processing chamber;    biasing the substrate with a power of less than 100 W;    etching the chromium layer exposed through the patterned hard mask; and    removing the hard mask.    
     
     
         7 . The computer-readable media of  claim 1 , wherein the instructions, when executed by the controller, cause the method to further comprise: 
 removing the hard mask in-situ the chamber in which the chromium layer is etched.    
     
     
         8 . The computer-readable media of  claim 1 , wherein the instructions, when executed by the controller, cause the method to further comprise: 
 pulsing the bias power.    
     
     
         9 . A semiconductor processing chamber, comprising: 
 a chamber body having a substrate support pedestal disposed therein;    a reticle adapter disposed on the substrate support pedestal, the reticle adapter suitable for retaining a photomask reticle;    a gas panel coupled to the chamber body and configured to provide Cl 2  and CO into the processing body;    a power source interface with the chamber and configured to provide sufficient power as to form a plasma from Cl 2  and CO provided to the processing body;    a power source coupled to the substrate support pedestal;    a controller arranged to control the function of the processing chamber; and    computer-readable media containing instructions, that when executed by the controller, cause an etch method to be performed on a photomask reticle disposed on the reticle adapted, the photomask reticle having a carbon hard mask disposed over a chromium layer and a quartz layer, the instructions comprising:    instructions for flowing process gases into the processing chamber, the process gases comprising chlorine containing gas and CO gas;    instructions for energizing the process gas into a plasma; and    instructions for biasing the photomask reticle with a power of less than 100 W while the chromium layer is etched through the patterned hard mask.    
     
     
         10 . The semiconductor processing chamber of  claim 9 , wherein the computer-readable media further comprise instructions for providing about 50 to about 1000 sccm of chlorine containing gas into the chamber body.  
     
     
         11 . The semiconductor processing chamber of  claim 9 , wherein the computer-readable media further comprise instructions for flowing about 10 to about 500 sccm of CO into the processing chamber;  
     
     
         12 . The semiconductor processing chamber of  claim 9 , wherein the computer-readable media further comprise instructions for providing flowing at least one of Cl 2 , BCl 3 , or HCl into the processing chamber.  
     
     
         13 . The semiconductor processing chamber of  claim 9 , wherein the computer-readable media further comprise instructions for: 
 flowing about 300 sccm of Cl 2  into the processing chamber;    flowing about 150 sccm of CO into the processing chamber;    maintaining chamber pressure at around 3 mTorr;    applying a plasma source power at around 300 Watts; and    supplying a plasma bias power at around 8 Watts.    
     
     
         14 . The semiconductor processing chamber of  claim 9 , wherein the computer-readable media further comprise instructions for: 
 flowing about 200 to about 400 sccm of Cl 2  into the processing chamber; and    flowing about 100 to about 300 sccm of CO into the processing chamber.    
     
     
         15 . The semiconductor processing chamber of  claim 9 , wherein the computer-readable media further comprise instructions for: 
 pulsing the bias power.    
     
     
         16 . A method for etching a photomask reticle comprising: 
 robotically transferring a photomask reticle to an opening of a reticle adapted in a processing chamber;    forming a plasma within the processing chamber from CO and Cl-containing gases;    etching a chromium layer through a patterned carbon-containing hard mask layer in the presence of the plasma.    
     
     
         17 . The method of  claim 16  further comprising: 
 biasing the photomask reticle with a power of less than 100 W while the chromium layer is etched through the patterned hard mask.