Gas cluster ion beam etching process for achieving target etch process metrics for multiple materials

Abstract

A method and system for performing gas cluster ion beam (GCIB) etch processing of various materials is described. In particular, the GCIB etch processing includes setting one or more GCIB properties of a GCIB process condition for the GCIB to achieve one or more target etch process metrics.

What is claimed is: 
     
         1 . A method for etching material on a substrate, comprising:
 maintaining a reduced-pressure environment around a substrate holder for holding a substrate having a first material, a second material, and a surface exposing said first material and/or said second material;   holding said substrate securely within said reduced-pressure environment;   selecting one or more target etch process metrics, said target etch process metrics including an etch rate of said first material, an etch rate of said second material, an etch selectivity between said first material and said second material, a surface roughness of said first material, a surface roughness of said second material, an etch profile of said first material, and an etch profile of said second material;   forming a gas cluster ion beam (GCIB) from a pressurized gas containing at least one etching gas;   setting one or more GCIB properties of a GCIB process condition for said GCIB to achieve said one or more target etch process metrics;   accelerating said GCIB through said reduced-pressure environment; and   irradiating said GCIB onto at least a portion of said surface of said substrate to etch at least one of said first material and said second material.   
     
     
         2 . The method of  claim 1 , wherein said one or more GCIB properties of said GCIB process condition include a GCIB composition, a beam dose, a beam acceleration potential, a beam focus potential, a beam energy, a beam energy distribution, a beam angular distribution, a beam divergence angle, a flow rate of said GCIB composition, a stagnation pressure, a stagnation temperature, a background gas pressure for an increased pressure region through which said GCIB passes, or a background gas flow rate for an increased pressure region through which said GCIB passes. 
     
     
         3 . The method of  claim 2 , wherein said one or more GCIB properties of said GCIB process condition include a GCIB composition, and wherein said GCIB composition includes a first etching gas and a second etching gas. 
     
     
         4 . The method of  claim 3 , wherein said first etching gas contains Cl or Br, and said second etching gas contains F. 
     
     
         5 . The method of  claim 3 , wherein said first etching gas contains Cl 2 , and said second etching gas contains NF 3 . 
     
     
         6 . The method of  claim 3 , wherein said first etching gas contains a halomethane or a halide, and said second etching gas contains F, Cl, or Br. 
     
     
         7 . The method of  claim 3 , wherein said first etching gas contains C, H, and a halogen element, and said second etching gas contains F, Cl, or Br. 
     
     
         8 . The method of  claim 3 , wherein said first etching gas contains CHF 3 , CHCl 3 , or CHBr 3 , and said second etching gas contains NF 3  or Cl 2 . 
     
     
         9 . The method of  claim 3 , wherein said first etching gas and said second etching gas are continuously introduced to said GCIB during said irradiating. 
     
     
         10 . The method of  claim 3 , wherein said first etching gas and said second etching gas are alternatingly and sequentially introduced to said GCIB during said irradiating. 
     
     
         11 . The method of  claim 2 , further comprising:
 introducing an additive gas to said GCIB to alter said GCIB composition and achieve said one or more target etch process metrics.   
     
     
         12 . The method of  claim 1 , wherein said setting said one or more GCIB properties to achieve said one or more target etch process metrics includes setting a GCIB composition, a beam acceleration potential, a flow rate of said GCIB composition, and a background gas flow rate for an increased pressure region through which said GCIB passes to achieve two or more of a target etch rate for said first material and/or said second material, a target etch selectivity between said first material and said second material, and a target surface roughness for said first material and/or said second material. 
     
     
         13 . The method of  claim 12 , further comprising:
 adjusting said one or more GCIB properties to alter said target etch selectivity from a value less than unity to a value near or above unity.   
     
     
         14 . The method of  claim 12 , said target surface roughness for said first material and/or said second material is less than or equal to 5 Angstrom. 
     
     
         15 . The method of  claim 1 , further comprising:
 planarizing an upper surface of said substrate.   
     
     
         16 . The method of  claim 1 , further comprising:
 altering said one or more target etch process metrics to create one or more new target etch process metrics; and   setting one or more additional GCIB properties of an additional GCIB process condition for said GCIB to achieve said one or more new target etch process metrics.   
     
     
         17 . The method of  claim 1 , wherein said first material comprises photo-resist, and said second material comprises a Si-containing material, a Ge-containing material, a metal-containing material, a semiconductor material, or a chalcogenide material. 
     
     
         18 . The method of  claim 1 , wherein said first material comprises silicon, and said second material comprises a Si-containing material having Si and one or more elements selected from the group consisting of O, N, C, and Ge. 
     
     
         19 . The method of  claim 1 , wherein said first material comprises a Si-containing material, and said second material comprises a Ge-containing material. 
     
     
         20 . The method of  claim 1 , wherein said first material comprises a Si-containing material, and said second material comprises a metal-containing material.