Method for forming hole pattern

Abstract

A photosensitive material film is formed by applying, on an etch target film deposited on a semiconductor substrate, a photosensitive material containing a hardly alkaline-soluble base polymer including a polymer in which a principal chain has cycloolefin and a saturated or non-saturated polycyclic alkyl group is bonded to the principal chain, and an acid generator including an onium salt compound. The photosensitive material film is irradiated with ArF excimer laser through a photomask so as to form a hole-patterned photosensitive material film. A hole pattern is formed in said etch target film by subjecting the etch target film to plasma etching using plasma at a plasma density of 1×10 10 /cm 3 or more with the hole-patterned photosensitive material film used as an etching mask.

What is claimed is:  
     
         1 . A method for forming a hole pattern comprising the steps of: 
 forming a photosensitive material film by applying, on an etch target film deposited on a semiconductor substrate, a photosensitive material containing a hardly alkaline-soluble base polymer including a polymer in which a principal chain has cycloolefin and a saturated or non-saturated polycyclic alkyl group is bonded to the principal chain, and an acid generator including an onium salt compound;    forming a hole-patterned photosensitive material film by irradiating said photosensitive material film with ArF excimer laser through a photomask; and    forming a hole pattern in said etch target film by subjecting said etch target film to plasma etching using plasma at a plasma density of 1×10 10 /cm 3  or more with said hole-patterned photosensitive material film used as an etching mask.    
     
     
         2 . The method for forming a hole pattern of  claim 1 , 
 wherein said polymer includes a norbornene derivative.    
     
     
         3 . The method for forming a hole pattern of  claim 1 , 
 wherein said polymer includes norbornene and a norbornene derivative.    
     
     
         4 . The method for forming a hole pattern of  claim 1 , 
 wherein said polycyclic alkyl group is an adamantyl group, a tricyclodecyl group or a tetracyclododecyl group.    
     
     
         5 . The method for forming a hole pattern of  claim 1 , 
 wherein said plasma etching is carried out by using a first voltage for generating plasma and a second voltage for inducing ions of the plasma toward said semiconductor substrate.    
     
     
         6 . A method for forming a hole pattern comprising the steps of: 
 forming a photosensitive material film by applying, on an etch target film deposited on a semiconductor substrate, a photosensitive material containing a hardly alkaline-soluble base polymer including a polymer in which a principal chain is composed of cyclo with three or more folds ring, and an acid generator including an onium salt;    forming a hole-patterned photosensitive material film by irradiating said photosensitive material film with ArF excimer laser through a photomask; and    forming a hole pattern in said etch target film by subjecting said etch target film to plasma etching using plasma at a plasma density of 1×10 10 /cm 3  or more with said hole-patterned photosensitive material film used as an etching mask.    
     
     
         7 . The method for forming a hole pattern of  claim 6 , 
 wherein said polymer includes a tricyclodecene derivative, a tetracyclododecene derivative, a pentacyclopentadecene derivative or a hexacycloheptadecene derivative.    
     
     
         8 . The method for forming a hole pattern of  claim 6 , 
 wherein a saturated or non-saturated polycyclic alkyl group is bonded to the principal chain of said polymer.    
     
     
         9 . The method for forming a hole pattern of  claim 6 , 
 wherein said plasma etching is carried out by using a first voltage for generating plasma and a second voltage for inducing ions of the plasma toward said semiconductor substrate.