Method of forming fine pattern

Abstract

A method of forming a fine pattern according to an embodiment includes: forming a hard mask on a substrate; forming a mask reinforcing member on the hard mask; forming a di-block copolymer layer on the mask reinforcing member, the di-block copolymer layer comprising a sea-island structure; forming a pattern comprising a concave-convex structure in the di-block copolymer layer, with island portions of the sea-island structure being convex portions; and transferring the pattern onto the hard mask by performing etching on the mask reinforcing member and the hard mask, with a mask being the pattern formed in the di-block copolymer layer. The mask reinforcing member is comprised of a material having an etching speed that is higher than an etching speed for the hard mask and is lower than an etching speed for sea portions of the sea-island structure of the di-block copolymer layer.

What is claimed is: 
     
         1 . A method of forming a fine pattern, the method comprising:
 forming a hard mask on a substrate;   forming a mask reinforcing member on the hard mask;   forming a di-block copolymer layer on the mask reinforcing member, the di-block copolymer layer comprising a sea-island structure;   forming a pattern comprising a concave-convex structure in the di-block copolymer layer, with island portions of the sea-island structure being convex portions; and   transferring the pattern onto the hard mask by performing etching on the mask reinforcing member and the hard mask, with a mask being the pattern formed in the di-block copolymer layer, wherein   the mask reinforcing member is comprised of a material having an etching speed that is higher than an etching speed for the hard mask and is lower than an etching speed for sea portions of the sea-island structure of the di-block copolymer layer.   
     
     
         2 . The method according to  claim 1 , wherein the condition, 0<t<d, is satisfied, where d (nm) represents a diameter of each of the island portions forming the sea-island structure of the di-block copolymer layer, and t (nm) represents a film thickness of the mask reinforcing member. 
     
     
         3 . The method according to  claim 1 , wherein the mask reinforcing member is comprised of one of or a combination of polyvinylnaphthalene (PVN), polyhydrostyrene (PHS), polyvinylbiphenyl (PVB), polystyrene (PS), and polydimethylsilohexane (PDMS). 
     
     
         4 . The method according to  claim 1 , wherein a material of the island portions forming the sea-island structure of the di-block copolymer layer is the same as the material of the mask reinforcing member. 
     
     
         5 . The method according to  claim 1 , wherein the di-block copolymer layer is comprised of a copolymer of polystyrene and polydimethylcyclohexane, and the mask reinforcing member is comprised of polydimethylsilohexane. 
     
     
         6 . The method according to  claim 1 , further comprising
 transferring the pattern onto the substrate by performing etching on the substrate with the use of the hard mask onto which the pattern is transferred.   
     
     
         7 . The method according to  claim 1 , wherein the hard mask comprises a structure in which a first hard mask containing carbon, a second hard mask containing silicon, and a third hard mask containing carbon are stacked in this order. 
     
     
         8 . The method according to  claim 1 , wherein
 a ferromagnetic layer is formed on the substrate, and   the method further comprises transferring the pattern onto the ferromagnetic layer by performing etching on the ferromagnetic layer with the use of the hard mask onto which the pattern is transferred.   
     
     
         9 . The method according to  claim 1 , wherein the etching on the mask reinforcing member and the hard mask is performed with the use of oxygen.