Line edge roughness reduction for trench etch

Abstract

A method for etching a trench to a trench depth in a dielectric layer over a substrate is provided. An ARC is applied over the dielectric layer. A photoresist mask is formed on the ARC, where the photoresist mask has a thickness. The ARC is etched through. A trench is etched into the dielectric layer with a dielectric to photoresist etch selectivity between 1:1 and 2:1.

1 - 13 . (canceled)  
   
   
       14 . An apparatus for etching a feature in a dielectric layer, comprising: 
 a plasma processing chamber, comprising: 
 a chamber wall forming a plasma processing chamber enclosure;  
 a substrate support for supporting a substrate within the plasma processing chamber enclosure;  
 a pressure regulator for regulating the pressure in the plasma processing chamber enclosure;  
 an electrode placed opposite from and spaced apart from the substrate support;  
 a heater connected to the electrode for heating the electrode;  
 a gas inlet for providing gas into the plasma processing chamber enclosure; and  
 a gas outlet for exhausting gas from the plasma processing chamber enclosure;  
   a gas source in fluid connection with the gas inlet,    a controller controllably connected to at least one of the gas source the electrode, the heater, the pressure regulator, the gas inlet, and the gas outlet.    
   
   
       15 . The apparatus, as recited in  claim 14 , wherein the controller comprises: 
 at least one processor; and    computer readable media, comprising: 
 computer readable code for providing an etch plasma for etching a feature into a dielectric layer; and  
 computer readable code for heating the electrode during etching so that the electrode reaches a temperature of at least 70° C.  
   
   
   
       16 . The apparatus, as recited in  claim 15 , wherein the computer readable media, further comprises computer readable code for maintaining the pressure between 60 mTorr and 400 mTorr.  
   
   
       17 . The apparatus, as recited in  claim 16 , wherein computer readable code for providing an etch plasma for etching a feature into the dielectric layer comprises computer readable code for provide a high frequency power between 500 W and 2000 W.  
   
   
       18 . The apparatus, as recited in  claim 17 , wherein computer readable code for heating the electrode during etching heats the electrode so that the electrode reaches a temperature of at least 90° C.  
   
   
       19 . The apparatus, as recited in  claim 17 , wherein computer readable code for heating the electrode during etching heats the electrode so that the electrode reaches a temperature of at least 140° C.  
   
   
       20 . The apparatus, as recited in  claim 19 , wherein the computer readable media further comprises computer readable code for providing a bias power between 0 W and 1000 W.  
   
   
       21 . The apparatus, as recited in  claim 20 , wherein the computer readable media further comprises computer readable code for providing an etchant gas selected from the group of CF 4 , C 2 F 6 , NF 3 , and SF 6 .  
   
   
       22 . The apparatus, as recited in  claim 14 , wherein the controller comprises: 
 at least one processor; and    computer readable media, comprising: 
 computer readable code for providing an etch plasma for etching a feature into a dielectric layer; and  
 computer readable code for heating the electrode during etching so that the electrode reaches a temperature of at least 90° C.  
   
   
   
       23 . The apparatus, as recited in  claim 14 , wherein the controller comprises: 
 at least one processor; and    computer readable media, comprising: 
 computer readable code for providing an etch plasma for etching a feature into a dielectric layer; and  
 computer readable code for heating the electrode during etching so that the electrode reaches a temperature of at least 140° C.  
   
   
   
       24 . The apparatus, as recited in  claim 23 , wherein the computer readable media, further comprises computer readable code for maintaining the pressure between 60 mTorr and 400 mTorr.  
   
   
       25 . The apparatus, as recited in  claim 24 , wherein the computer readable media further comprises computer readable code for providing a bias power between 0 W and 1000 W.  
   
   
       26 . The apparatus, as recited in  claim 25 , wherein the computer readable media further comprises computer readable code for providing an etchant gas selected from the group of CF 4 , C 2 F 6 , NF 3 , and SF 6 .  
   
   
       27 . The apparatus, as recited in  claim 14 , wherein the controller comprises: 
 at least one processor; and    computer readable media, comprising computer readable code for maintaining the pressure between 60 mTorr and 400 mTorr.    
   
   
       28 . The apparatus, as recited in  claim 14 , wherein the controller comprises: 
 at least one processor; and    computer readable media, comprising computer readable code for providing a high frequency power between 500 W and 2000 W.    
   
   
       29 . The apparatus, as recited in  claim 14 , wherein the controller comprises: 
 at least one processor; and    computer readable media, comprising computer readable code for providing a bias power between 0 W and 1000 W.    
   
   
       30 . The apparatus, as recited in  claim 14 , wherein the controller comprises: 
 at least one processor; and    computer readable media, comprising computer readable code for providing an etchant gas selected from the group of CF 4 , C 2 F 6 , NF 3 , and SF 6 .