Method for Integrated Circuit Patterning

Abstract

Provided is a method of patterning a substrate. The method includes patterning a resist layer formed over the substrate to result in a resist pattern and treating the resist pattern with an ion beam. The ion beam is generated with a gas, such as CH 4 , SiH 4 , Ar, or He; and is directed towards the resist pattern at a tilt angle at least 10 degrees. In embodiments, the ion beam is directed towards the resist pattern at a uniform twist angle, or at a twist angle having a unimodal or bimodal distribution. The ion beam reduces line edge roughness (LER), line width roughness (LWR), and/or critical dimension of the resist pattern. The method further includes etching the substrate with the treated resist pattern as an etch mask.

What is claimed is: 
     
         1 . A method of patterning a substrate, the method comprising:
 patterning a resist layer formed over the substrate, resulting in a resist pattern;   treating the resist pattern with an ion beam, resulting in a treated resist pattern, wherein the ion beam is generated with a first gas and is directed towards the resist pattern at a tilt angle at least 10 degrees; and   etching the substrate with the treated resist pattern as an etch mask.   
     
     
         2 . The method of  claim 1 , wherein the ion beam is directed towards the resist pattern at a uniform twist angle. 
     
     
         3 . The method of  claim 1 , wherein the ion beam is directed towards the resist pattern at a twist angle having a unimodal distribution from about −50 degrees to about 50 degrees. 
     
     
         4 . The method of  claim 1 , wherein the ion beam is directed towards the resist pattern at a twist angle having a bimodal distribution. 
     
     
         5 . The method of  claim 4 , wherein the bimodal distribution has one ion energy peak at about 12.5 degrees and another ion energy peak at about −12.5 degrees. 
     
     
         6 . The method of  claim 1 , wherein the first gas is Ar and the ion beam is provided with ion energy from about 1.0 kV to about 3.5 kV and ion dose from about 1×e 16  ions/cm 2  to about 10×e 16  ions/cm 2 . 
     
     
         7 . The method of  claim 1 , wherein the first gas is He and the ion beam is provided with ion energy from about 1 kV to about 5 kV and ion dose from about 1×e 16  ions/cm 2  to about 10×e 16  ions/cm 2 . 
     
     
         8 . The method of  claim 1 , wherein the first gas is SiH 4  and the ion beam is provided with ion energy from about 2 kV to about 5 kV and ion dose from about 0.5×e 16  ions/cm 2  to about 3×e 16  ions/cm 2 . 
     
     
         9 . The method of  claim 1 , wherein the first gas is CH 4  and the ion beam is provided with ion energy from about 1 kV to about 5 kV and ion dose from about 1×e 16  ions/cm 2  to about 6×e 16  ions/cm 2 . 
     
     
         10 . The method of  claim 1 , wherein the first gas is one of: CH 4 , SiH 4 , Ar, He, O 2 , N 2 , CO 2 , and a combination thereof. 
     
     
         11 . A method of patterning an etch layer over a substrate, the method comprising:
 forming a resist layer over the etch layer;   patterning the resist layer, resulting in a patterned resist layer;   performing ion implantation to the patterned resist layer, resulting in a treated patterned resist layer, wherein the performing ion implantation comprises:
 providing a treatment gas containing CH 4 , SiH 4 , Ar, or He; 
 generating an ion beam from the treatment gas; and 
 directing the ion beam incident upon the substrate at a tilt angle; and 
   etching the etch layer with the treated patterned resist layer as an etch mask.   
     
     
         12 . The method of  claim 11 , wherein the ion beam has an ion dose of at least 0.5×e 16  ions/cm 2 . 
     
     
         13 . The method of  claim 11 , wherein the tilt angle is at least 10 degrees. 
     
     
         14 . The method of  claim 11 , wherein the ion beam is directed incident upon the substrate with a uniform twist angle. 
     
     
         15 . The method of  claim 11 , wherein the ion beam is directed incident upon the substrate at a twist angle having a unimodal distribution. 
     
     
         16 . The method of  claim 11 , wherein the ion beam is directed incident upon the substrate at a twist angle having a bimodal distribution. 
     
     
         17 . A method of forming an integrated circuit, the method comprising:
 patterning a material layer over a substrate, resulting in a patterned material layer;   treating the patterned material layer with an ion beam generated with one of: CH 4 , SiH 4 , Ar, and He, and directed incident upon the substrate at a tilt angle greater than 10 degrees, resulting in a treated patterned material layer; and   etching the substrate with the treated patterned material layer.   
     
     
         18 . The method of  claim 17 , wherein the material layer is a resist layer. 
     
     
         19 . The method of  claim 17 , wherein the material layer is a silicon-containing anti-reflection coating (ARC) layer. 
     
     
         20 . The method of  claim 17 , wherein the material layer contains silicon, carbon, and oxygen.