Method of patterning

Abstract

A method of reducing corner rounding during patterning of a substrate to form a prescribed pattern comprising a corner includes dividing the pattern into a first pattern and a second pattern, the first pattern forming a first edge of the corner and the second pattern forming a second edge of the corner. At least a portion of the second pattern overlaps the first pattern such that the first edge intersects with the second edge to form a corner of the prescribed pattern. The method further includes forming the first pattern in a first mask layer disposed on a substrate to expose the substrate and forming the second pattern in the first mask layer to expose the substrate. The substrate exposed through the first mask layer is then etched to obtain the pattern.

What is claimed is: 
     
         1 . A method of patterning to obtain a prescribed pattern in a substrate, the prescribed pattern having one or more first edges in a first direction and one or more second edges in a second direction, the first edges and the second edges forming corners of the prescribed pattern, the method comprising:
 dividing the prescribed pattern into a first pattern forming one or more of the first edges and a second pattern forming one or more of the second edges;   forming a first mask layer over the substrate;   forming a second mask layer over the first mask layer;   forming the second pattern over the second mask layer;   removing a first portion of the second mask layer using the second pattern;   forming the first pattern over the first mask layer, at least a portion of the second pattern overlapping the first pattern to form the corners of the prescribed pattern;   removing a portion of the first mask layer exposed through the second mask layer to expose a portion of the substrate; and   etching the substrate exposed through the first mask layer and the second mask layer to obtain the prescribed pattern.   
     
     
         2 . The method of  claim 1 , further comprising, prior to forming the second pattern, etching a first of the two or more materials of the portion of the substrate exposed by the first pattern. 
     
     
         3 . The method of  claim 2 , further comprising, prior to forming the second pattern, filling the etched portion of the substrate exposed by the first pattern with a second material different from the first material. 
     
     
         4 . The method of  claim 3 , wherein the second material is the same as a material of the substrate. 
     
     
         5 . The method of  claim 1 , wherein the first direction is orthogonal to the second direction. 
     
     
         6 . The method of  claim 1 , wherein the first mask layer has a material selected from silicon nitride and silicon dioxide. 
     
     
         7 . The method of  claim 1 , further comprising, prior to forming the second pattern, filling the first pattern with a first filler having a different etch selectivity from a material of the first mask layer. 
     
     
         8 . A method of reducing corner rounding during patterning of a substrate having two or more materials to form a prescribed pattern comprising a corner, the method comprising:
 dividing the prescribed pattern into a first pattern and a second pattern, the first pattern forming a first edge of the corner and the second pattern forming a second edge of the corner, wherein at least a portion of the second pattern overlaps the first pattern such that the first edge intersects with the second edge to form a first corner of the prescribed pattern;   forming the first pattern in a first mask layer disposed over a substrate to expose the substrate;   forming the second pattern in the first mask layer to expose the substrate;   prior to forming the second pattern, etching a first of the two or more materials of the substrate exposed by the first pattern; and   etching the substrate exposed through the first mask layer to obtain the prescribed pattern.   
     
     
         9 . The method of  claim 18 , wherein the two or more materials are disposed in a preexisting pattern in a portion exposed by the first pattern, and the method further comprises, prior to forming the second pattern, etching a first of the two or more materials of the portion of the substrate exposed by the first pattern. 
     
     
         10 . The method of  claim 8 , further comprising, prior to the etching the substrate, removing a portion of the first mask layer using the second pattern, forming a second mask layer, forming a third pattern in the second mask layer, and removing the second mask layer using the third pattern, wherein at least a portion of the third pattern overlaps the first pattern such that at least edge of the first pattern intersects with at least one edge of the third pattern to form a second corner of the prescribed pattern. 
     
     
         11 . The method according to  claim 8 , wherein the first of the two or more materials is a pattern of lines separated by spacers comprising a second of the two or more materials. 
     
     
         12 . The method according to  claim 11 , wherein the second material is a different material than the first material. 
     
     
         13 . The method according to  claim 12 , wherein the first material is silicon nitride, silicon dioxide, doped silicon, or a metallic material. 
     
     
         14 . The method according to  claim 13 , wherein the second material is silicon nitride, silicon dioxide, or a doped silicon. 
     
     
         15 . A method, comprising:
 forming a first mask layer over a substrate,   wherein the substrate comprises a plurality of line patterns and spacers, wherein the spacers are interposed between adjacent line patterns;   forming a first pattern in the first mask layer exposing a first one or more line patterns of the plurality of line patterns;   forming a second mask layer over the first pattern;   forming a second pattern in the second mask layer overlapping a portion of the first pattern, wherein the second pattern exposes a part of the first mask layer and the first one or more line patterns;   removing the exposed first one or more line patterns forming a first space in the substrate;   filling the first space with a filler material;   forming a third mask layer over the substrate;   forming a third pattern in third mask layer exposing a part of the filler material and the first mask layer;   removing the exposed first mask layer exposing a second one or more line patterns of the plurality of line patterns;   removing the second one or more line patterns to form second spaces; and   removing remaining parts of the first mask layer, the second mask layer, the third mask layer, and the filler material.   
     
     
         16 . The method according to  claim 15 , wherein the exposed part of the first mask layer is not removed when the first one or more line patterns are removed. 
     
     
         17 . The method according to  claim 15 , further comprising performing chemical mechanical polishing after filling the first space with the filler material. 
     
     
         18 . The method according to  claim 15 , wherein the first mask layer and the second mask layer have etch selectivity with respect to each other. 
     
     
         19 . The method according to  claim 15 , wherein the filler material and the spacers comprise a same material. 
     
     
         20 . The method according to  claim 15 , wherein the filler material is titanium nitride.