Image transfer using euv lithographic structure and double patterning process

Abstract

An EUV lithographic structure includes an EUV photosensitive resist layer disposed on a hardmask layer, wherein the EUV lithographic structure is free of an antireflective coating. An organic adhesion layer can be provided between the hardmask layer and the EUV photosensitive resist layer. The hardmask layer can include an uppermost oxide hardmask layer, an intermediate hardmask layer, and a lowermost oxide hardmask layer, wherein the EUV photosensitive resist layer is disposed on the uppermost oxide hardmask layer. Also described are methods for patterning the EUV lithographic structures.

What is claimed is: 
     
         1 . A method comprising:
 forming an organic planarizing layer over a semiconductor substrate, the organic planarizing layer including a planar upper surface;   forming a hardmask layer on the planar upper surface of the organic planarizing layer;   forming an organic adhesion layer on the hardmask layer;   forming an EUV photosensitive resist layer on the organic adhesion layer;   exposing and developing the EUV photosensitive resist layer with an EUV light source to form an opening therein;   transferring the opening in the EUV photosensitive resist layer to the hardmask layer by reactive ion etching; and   extending the opening into the organic planarizing layer and to the substrate by reactive ion etching.   
     
     
         2 . The method of  claim 1 , wherein the semiconductor substrate comprises a layer containing topographical features. 
     
     
         3 . The method of  claim 1 , wherein the hardmask layer comprises an uppermost oxide hardmask layer, an intermediate hardmask layer, and a lowermost oxide hardmask layer, wherein the EUV photosensitive resist layer is deposited directly onto the uppermost hardmask layer. 
     
     
         4 . The method of  claim 3 , wherein the uppermost and lowermost hardmask layers comprise a low temperature oxide. 
     
     
         5 . The method of  claim 3 , wherein the intermediate hardmask layer comprises titanium nitride or an organosilicon. 
     
     
         6 . The method of  claim 1  further comprising:
 forming an additional EUV photosensitive resist layer on the hardmask layer including the opening; and 
 exposing and developing the additional EUV photosensitive resist layer with the EUV light source to form an additional opening therein; 
 wherein forming the additional opening therein is prior to extending the opening into the organic planarizing layer to the substrate. 
 
     
     
         7 . The method of  claim 1 , wherein the opening has a critical dimension of about 14 nanometers and the organic planarizing layer has a thickness of about 60 to 100 nanometers. 
     
     
         8 . The method of  claim 1 , wherein the intermediate hardmask layer comprises octylmethylcyclotetrasiloxane. 
     
     
         9 . The method of  claim 1  further comprising removing the intermediate hardmask layer by a wet etch process. 
     
     
         10 . A method comprising:
 forming an organic planarizing layer over topography formed on a semiconductor substrate, the organic planarizing layer including a planar upper surface;   forming a multilayer hardmask layer on the planar upper surface of the organic planarizing layer comprising an uppermost oxide hardmask layer, an intermediate hardmask layer, and a lowermost oxide hardmask layer;   forming an organic adhesion layer on the uppermost oxide hardmask layer;   forming an EUV photosensitive resist layer on the organic adhesion layer;   exposing and developing the EUV photosensitive resist layer with an EUV light source to form an opening therein;   reactive ion etching to transfer the opening in the EUV sensitive photoresist layer to the uppermost hardmask layer;   forming an additional EUV photosensitive resist layer on the uppermost hardmask layer including the opening;   exposing and developing the EUV photosensitive resist layer with an EUV light source to form an additional opening therein;   reactive ion etching to extend the opening and the additional opening into the intermediate hardmask layer and to the lowermost hardmask layer;   removing the intermediate hardmask layer; and   reactive ion etching to extend the opening and the additional opening into the lowermost oxide hardmask layer and the organic planarizing layer within the same etch chamber.   
     
     
         11 . The method of  claim 10 , wherein the opening has a critical dimension of about 14 nanometers and the organic planarizing layer has a thickness of about 60 to 100 nanometers. 
     
     
         12 . The method of  claim 10 , wherein the intermediate hardmask layer comprises octylmethylcyclotetrasiloxane. 
     
     
         13 . The method of  claim 10 , wherein removing the intermediate hardmask layer comprises a wet etch process. 
     
     
         14 . The method of  claim 10 , wherein the uppermost and lowermost hardmask layers comprise a low temperature oxide, and wherein the intermediate hardmask layer comprises titanium nitride or octylmethylcyclotetrasiloxane. 
     
     
         15 . The method of  claim 10 , wherein the EUV photosensitive resist is chemically amplified upon exposure to the EUV light source.