Apparatus of processing a sample surface and method thereof

Abstract

A surface processing apparatus is provided. In the apparatus, an etching rate ratio of an organic material such as a BARC of anti-reflective film to a resist of mask forming a pattern, that is, a selective ratio is high, the anti-reflective film being a means for forming the pattern with a high accuracy in surface processing of a semiconductor. In the surface processing apparatus using a plasma, a deposition gas is added to a light element of hydrogen as the etching gas. Ions accelerated by a bias electric power supply accelerate etching reaction. Sputtering at edges of the mask can be reduced by using the light element of hydrogen as the etching gas, and the selective ratio of the anti-reflective film to the masking material can be increased by mixing the deposition gas with the hydrogen.

What is claimed is:  
     
         1 . An apparatus of processing a sample surface comprising a vacuum chamber; a means for generating a plasma in said vacuum chamber; a sample table for mounting a sample to be performed with surface processing using said plasma; and an electric power supply for applying a radio frequency bias to the sample, the surface processing of the sample being performed using a masking material and an anti-reflective film, the apparatus further comprising 
 means for introducing a mixed gas of hydrogen gas and a deposition gas as an etching gas into said vacuum chamber.    
     
     
         2 . An apparatus of processing a sample surface according to    claim 1   , wherein an amount of said deposition gas added to said hydrogen gas is set to a value, said value being around an amount E 0  at which a cut-down amount of said masking material becomes zero and within a range in which a selective ratio of said anti-reflective film to said masking material is larger than 2.  
     
     
         3 . A method of processing a sample surface which performs surface processing of a sample by using a plasma by generating the plasma in a vacuum chamber; applying a radio frequency bias to a sample table mounting the sample; using a masking material and an anti-reflective film, the method comprising the step of 
 introducing a mixed gas of hydrogen gas and a deposition gas as an etching gas into said vacuum chamber.    
     
     
         4 . A method of processing a sample surface according to    claim 3   , wherein an amount of said deposition gas added to said hydrogen gas is set to a value, said value being an amount E 0  at which a cut-down amount of said masking material becomes zero.  
     
     
         5 . A method of processing a sample surface according to any one of    claim 3    and    claim 4   , wherein said deposition gas mixed with said hydrogen gas is a gas containing carbon as a constituent element.  
     
     
         6 . A method of processing a sample surface according to any one of    claim 3    and    claim 4   , wherein said deposition gas contains one kind selected from the group consisting of CHF 3 , CH 2 F 2  and CF 4 .