Method for fabricating an aperture

Abstract

A method for fabricating an aperture is disclosed. The method includes the steps of: forming a hard mask containing carbon on a surface of a semiconductor substrate; and using a non-oxygen element containing gas to perform a first etching process for forming a first aperture in the hard mask. Before forming the hard mask, a gate which includes a contact etch stop layer and a dielectric layer is formed on the semiconductor substrate.

What is claimed is: 
     
         1 . A method for fabricating an aperture, comprising:
 forming a hard mask containing amorphous carbon on a surface of a semiconductor substrate; and   using a non-oxygen element containing gas to perform a first etching process for forming a first aperture in the hard mask, wherein the non-oxygen element containing gas consists of H 2  and N 2 .   
     
     
         2 . The method of  claim 1 , wherein after forming the hard mask comprises:
 forming a dielectric anti-reflective coating, a bottom anti-reflective coating, and a patterned resist on the hard mask;   using the patterned resist to perform a second etching process for forming a second aperture in the bottom anti-reflective coating and the dielectric anti-reflective coating; and   using the patterned resist to perform the first etching process for forming the first aperture in the hard mask.   
     
     
         3 . The method of  claim 1 , further comprising forming agate structure on the semiconductor substrate before forming the hard mask, wherein the gate structure comprises a contact etch stop layer and a dielectric layer thereon. 
     
     
         4 . The method of  claim 3 , wherein the gate structure comprises a polysilicon gate or a metal gate. 
     
     
         5 . The method of  claim 3 , further comprising using the first aperture to define a rectangular slot opening along the horizontal axis of the gate structure.