Trench patterning with block first sidewall image transfer

Abstract

A method including forming a tetra-layer hardmask above a substrate, the tetra-layer hardmask including a second hardmask layer above a first hardmask layer; removing a portion of the second hardmask layer of the tetra-layer hardmask within a pattern region of a structure comprising the substrate and the tetra-layer hardmask; forming a set of sidewall spacers above the tetra-layer hardmask to define a device pattern; and transferring a portion of the device pattern into the substrate and within the pattern region of the structure.

What is claimed is: 
     
         1 . A method comprising:
 forming a tetra-layer hardmask above a substrate, the tetra-layer hardmask comprising a second hardmask layer above a first hardmask layer;   removing a portion of the second hardmask layer of the tetra-layer hardmask within a pattern region of a structure comprising the substrate and the tetra-layer hardmask;   forming a set of sidewall spacers above the tetra-layer hardmask defining a device pattern; and   transferring a portion of the device pattern into the substrate within the pattern region of the structure.   
     
     
         2 . The method of  claim 1 , wherein forming the set of sidewall spacers above the tetra-layer hardmask defining the device pattern comprises:
 creating a mandrel, lithographically, from a photo-resist material;   depositing a conformal layer of dielectric material covering the mandrel;   performing a directional etch of the conformal layer of dielectric material forming the set of sidewall spacers; and   removing the mandrel.   
     
     
         3 . The method of  claim 1 , wherein transferring the portion of the device pattern into the substrate within the pattern region of the structure comprises:
 transferring the portion of the device pattern into the first hardmask layer within the pattern region of the structure; and   transferring the portion of the device pattern from the first hardmask layer into the substrate within the pattern region of the structure.   
     
     
         4 . The method of  claim 3 , wherein transferring the portion of the device pattern into the first hardmask layer within the pattern region of the structure comprises:
 transferring the portion of the device pattern into a mandrel planarization layer above the tetra-layer hardmask; and   transferring the portion of the device pattern from the mandrel planarization layer into the first hardmask layer.   
     
     
         5 . The method of  claim 1 , wherein forming the tetra-layer hardmask above the substrate comprises:
 forming a first patterning layer directly above the substrate;   forming the first hardmask layer directly above the first patterning layer;   forming a second patterning layer directly above the first hardmask layer; and   forming the second hardmask layer directly above the second patterning layer.   
     
     
         6 . The method of  claim 1 , further comprising:
 depositing a metal within the device pattern transferred into the substrate.   
     
     
         7 . A method comprising:
 forming a tetra-layer hardmask comprising a second hardmask layer above a first hardmask layer;   defining a pattern region in the second hardmask layer;   forming a device pattern above the tetra-layer hardmask; and   transferring the device pattern into a substrate below the tetra-layer hardmask, wherein the device pattern is transferred into the substrate only in the pattern region defined by the second hardmask layer.   
     
     
         8 . The method of  claim 7 , wherein defining the pattern region is accomplished using a lithographic masking and etching technique. 
     
     
         9 . The method of  claim 7 , wherein forming a device pattern above the tetra-layer hardmask comprises:
 creating a mandrel, lithographically, from a photo-resist material;   depositing a conformal layer of dielectric material covering the mandrel;   performing a directional etch of the conformal layer of dielectric material forming a set of sidewall spacers; and   removing the mandrel.   
     
     
         10 . The method of  claim 7 , wherein forming the device pattern above the tetra-layer hardmask comprises:
 forming a first device pattern intended to fabricate an interconnect structure; and   forming a second device pattern intended to fabricate an alignment mark.   
     
     
         11 . The method of  claim 7 , wherein transferring the device pattern is accomplished using a sidewall image transfer technique. 
     
     
         12 . The method of  claim 7 , wherein transferring the device pattern into the substrate below the tetra-layer hardmask comprises:
 transferring the device pattern into a mandrel ARC layer above a mandrel planarization layer above the tetra-layer hardmask; and   transferring the device pattern from the mandrel ARC layer into the mandrel planarization layer;   transferring the device pattern from the mandrel planarization layer into the first hardmask layer; and   transferring the device pattern from the first hardmask layer into the substrate.   
     
     
         13 . The method of  claim 7 , wherein forming the tetra-layer hardmask comprises:
 forming a first patterning layer directly above the substrate;   forming the first hardmask layer directly above the first patterning layer;   forming a second patterning layer directly above the first hardmask layer; and   forming the second hardmask layer directly above the second patterning layer.   
     
     
         14 . A method comprising:
 forming a tetra-layer hardmask above a substrate, the tetra-layer hardmask comprising a first patterning layer, a first hardmask layer, a second patterning layer, and a second hardmask layer all of which are formed one top of one another and in sequence;   forming a block pattern from a first photo-resist material above the tetra-layer hardmask;   transferring the block pattern from the first photo-resist material into the second hardmask layer, wherein the block pattern in the second hardmask layer defines a pattern region;   forming a device pattern using a set of sidewall spacers above the second hardmask layer;   transferring the device pattern into the first hardmask layer, only within the pattern region; and   transferring the device pattern into the substrate, only within the pattern region.   
     
     
         15 . The method of  claim 14 , wherein forming the device pattern using the set of sidewall spacers above the second hardmask layer comprises:
 creating a mandrel, lithographically, from a second photo-resist layer;   depositing a conformal layer of dielectric material covering the mandrel;   performing a directional etch of the conformal layer of dielectric material forming the set of sidewall spacers; and   removing the mandrel.   
     
     
         16 . The method of  claim 14 , wherein forming the device pattern using the set of sidewall spacers above the second hardmask layer comprises:
 forming a first device pattern intended to fabricate an interconnect structure; and   forming a second device pattern intended to fabricate an alignment mark.   
     
     
         17 . The method of  claim 14 , wherein transferring the device pattern into the first hardmask layer comprises:
 transferring the device pattern into a mandrel ARC layer above a mandrel planarization layer above the tetra-layer hardmask; and   transferring the device pattern from the mandrel ARC layer into the mandrel planarization layer; and   transferring the device pattern from the mandrel planarization layer into the first hardmask layer.