Pitch division patterning techniques

Abstract

Embodiments of the invention comprise pitch division techniques to extend the capabilities of lithographic techniques beyond their minimum pitch. The pitch division techniques described herein employ additional processing to ensure pitch divided lines have the spatial isolation necessary to prevent shorting problems. The pitch division techniques described herein further employ processing acts to increase the structural robustness of high aspect ratio features.

1 . A method comprising:
 depositing a spacer layer on a first pattern etched on a first hard mask layer of a patterning stack, the first pattern based, at least in part, on an at least one photo-resist pad placed to overlap a first set of lines, the patterning stack to further include a second hard mask layer;   selectively removing the first hard mask layer to form a set of spacers that comprise a second pattern; and   transferring the second pattern onto the second hard mask layer.   
     
     
         2 . The method of  claim 1 , further comprising:
 applying a photo pattern to expose an end for each of the set of spacers, wherein the exposed ends are spatially isolated from each other;   applying a photo pattern of a contact landing pad to each of the exposed ends of the second set of spacers to form a mask pattern; and   transferring the mask pattern onto the second hard mask layer.   
     
     
         3 . The method of  claim 1 , wherein the first pattern is formed by
 depositing an initial spacer layer on a photo resist pattern of the patterning stack, the photo resist pattern having a first lateral dimension;   selectively removing the photo resist pattern to expose an initial set of spacers, the initial set of spacers to have a lateral dimension approximately ¼ of the first lateral dimension;   placing the at least one photo resist pad to overlap the initial set of spacers; and   etching the pattern formed by the at least one photo resist pad and the initial set of spacers onto the first hard mask layer to form the first pattern.   
     
     
         4 . The method of  claim 1 , wherein the first pattern is formed by
 depositing an initial spacer layer on a photo resist pattern of the patterning stack, the photo resist pattern having a first lateral dimension;   selectively removing the photo resist pattern to expose an initial set of spacers, the initial set of spacers to have a lateral dimension approximately ¼ of the first lateral dimension;   etching the initial set of spacers onto the first hard mask layer; and   placing the at least one photo resist pad to overlap the etched initial set of spacers on the first hard mask layer to form the first pattern.   
     
     
         5 . The method of  claim 1 , wherein the first and second hard mask layers comprise at least one of transparent carbon, amorphous carbon, silicon containing hardmask, and metal containing hardmask. 
     
     
         6 . The method of  claim 1 , wherein the spacer layer comprises at least one of a spacer oxide layer and a spacer nitride layer. 
     
     
         7 . The method of  claim 3 , wherein selectively removing the photo resist pattern and selectively removing the first hardmask layer comprises at least one of a plasma and a wet chemical etching process. 
     
     
         8 . The method of  claim 1 , wherein transferring the second pattern onto the second hard mask layer comprises performing a reactive ion etch (RIE). 
     
     
         9 . A method comprising:
 depositing a spacer layer on a pattern included in a first hard mask layer to develop a set of spacers, the first hard mask layer included on a patterning stack, the patterning stack further including a second hard mask layer;   filling the pattern included in the first hard mask layer with a filling material;   removing some of the filling material and the spacers to form a first set of lines;   transferring the filled pattern and the first set of lines to the second hard mask layer; and   exposing a chop pattern on the pattern on the second hard mask layer to create a second set of lines spatially isolated from the first set of lines.   
     
     
         10 . The method of  claim 9 , further comprising:
 exposing an initial chop pattern on the filled first hard mask layer to create the first set lines comprising the filling material.   
     
     
         11 . The method of  claim 9 , wherein the filling material, the first hard mask layer, and the second hard mask layer comprise the same material. 
     
     
         12 . The method of  claim 9 , wherein the filling material comprises at least one of a photo resist material and an organic etch resistant material. 
     
     
         13 . The method of  claim 9 , wherein the pattern included in the first hard mask layer is created by
 depositing an initial spacer layer on a photo resist pattern included on the patterning stack to develop an initial set of spacers, the photo resist pattern having a first lateral dimension;   selectively removing the photo resist pattern of the patterning stack to expose the initial set of spacers, the initial set of spacers to have a lateral dimension approximately ¼ of the first lateral dimension; and   transferring the initial set of spacers to the first hard mask layer to form the pattern.   
     
     
         14 . The method of  claim 9 , further comprising:
 transferring the first and second lines to a substrate further included in the patterning stack; and   patterning contact landing pads for interconnects on ends of the first and second lines.   
     
     
         15 . The method of  claim 9 , wherein the first and second hard mask layers comprise at least one of transparent carbon, amorphous carbon, silicon containing hardmask, and metal containing hardmask. 
     
     
         16 . The method of  claim 9 , wherein the spacer layer comprises at least one of a spacer oxide layer and a spacer nitride layer. 
     
     
         17 . The method of  claim 9 , wherein removing some of the filling material and the second set of spacers comprises performing at least one of a wet chemical etch and a reactive ion etch (RIE) on the filled first hard mask layer. 
     
     
         18 . A device formed from semiconductor material comprising:
 a spacer layer deposited on a pattern included in a first hard mask layer for developing a set of spacers, the first hard mask layer included on a patterning stack, the patterning stack further including a second hard mask layer;   a first set of lines formed from the set of spacers and filing material;   a second set of lines, spatially isolated from the first set of lines, formed from transferring the first set of lines to the second hard mask layer; and   contact landing pads patterned on ends of the first and second lines for interconnecting the CMOS circuitry.   
     
     
         19 . The device of  claim 18 , wherein the filling material, the first hard mask layer, and the second hard mask layer comprise the same material. 
     
     
         20 . The device of  claim 18 , wherein the first and second hard mask layers comprise at least one of transparent carbon, amorphous carbon, silicon containing hardmask, and metal containing hardmask, and wherein the spacer layer comprises at least one of a spacer oxide layer and a spacer nitride layer.