Extreme ultraviolet (euv) lithography patterning methods utilizing euv resist hardening

Abstract

Extreme ultraviolet (EUV) lithographic patterning methods are provided which implement a surface-hardened EUV resist mask to pattern features in multiple layers. A layer of EUV resist material is formed on a substrate. An EUV resist mask is formed by exposing and developing the layer of EUV resist material. A surface-hardened EUV resist mask is formed by applying a surface treatment to an upper surface of the EUV resist mask to form an etch-resistant layer that is embedded in the upper surface of the EUV resist mask. At least one layer of the substrate is patterned using the surface-hardened EUV resist mask. The surface treatment can be implemented using a neutral atom beam (NAB) process which is configured to implant a chemical or metallic species into the upper surface of the EUV resist mask to form the etch-resistant layer.

We claim: 
     
         1 . An extreme ultraviolet (EUV) lithographic patterning method, comprising:
 forming a layer of EUV resist material on a substrate;   forming an EUV resist mask by exposing and developing the layer of EUV resist material;   forming a surface-hardened EUV resist mask by applying a surface treatment to an upper surface of the EUV resist mask to form an etch-resistant layer that is embedded in the upper surface of the EUV resist mask; and   patterning at least one layer of the substrate using the surface-hardened EUV resist mask.   
     
     
         2 . The method of  claim 1 , wherein the EUV resist mask has a thickness which is about 20 nm or less. 
     
     
         3 . The method of  claim 1 , wherein the etch-resistant layer has a thickness which is about 3 nm or less. 
     
     
         4 . The method of  claim 1 , wherein applying the surface treatment to the upper surface of the EUV resist mask to form the etch-resistant layer comprises performing a neutral atom beam (NAB) process to implant a species into the upper surface of the EUV resist mask to form the etch-resistant layer. 
     
     
         5 . The method of  claim 1 , wherein the species comprises a chemical species. 
     
     
         6 . The method of  claim 4 , wherein the chemical species comprises one of argon (Ar), boron (B), silicon (Si), and flourine (F) atoms. 
     
     
         7 . The method of  claim 1 , wherein the species comprises a metallic species. 
     
     
         8 . The method of  claim 7 , wherein the metallic species comprises one of platinum (Pt), ruthenium (Ru), titanium (Ti), and tantalum (Ta). 
     
     
         9 . An extreme ultraviolet (EUV) lithographic patterning method, comprising:
 forming a multi-layer stack on a substrate, wherein the multilayer stack comprises a layer of EUV resist material formed over one or more additional layers of the multi-layer stack;   forming an EUV resist mask by exposing and developing the layer of EUV resist material;   forming a surface-hardened EUV resist mask by applying a surface treatment to an upper surface of the EUV resist mask to form an etch-resistant layer that is embedded in the upper surface of the EUV resist mask; and   patterning the one or more additional layers of the multi-layer stack using the surface-hardened EUV resist mask.   
     
     
         10 . The method of  claim 9 , wherein the EUV resist mask has a thickness which is about 20 nm or less. 
     
     
         11 . The method of  claim 9 , wherein the etch-resistant layer has a thickness which is about 3 nm or less. 
     
     
         12 . The method of  claim 9 , wherein applying the surface treatment to the upper surface of the EUV resist mask to form the etch-resistant layer comprises performing a neutral atom beam (NAB) process to implant a species into the upper surface of the EUV resist mask to form the etch-resistant layer. 
     
     
         13 . The method of  claim 9 , wherein the species comprises a chemical species. 
     
     
         14 . The method of  claim 13 , wherein the chemical species comprises one of argon (Ar), boron (B), silicon (Si), and flourine (F) atoms. 
     
     
         15 . The method of  claim 9 , wherein the species comprises a metallic species. 
     
     
         16 . The method of  claim 15 , wherein the metallic species comprises one of platinum (Pt), ruthenium (Ru), titanium (Ti), and tantalum (Ta). 
     
     
         17 . The method of  claim 9 , wherein the one or more additional layers of the multi-layer stack comprises:
 a hard mask antireflection coating layer; and   an organic planarizing layer,   wherein the hard mask antireflection coating layer is disposed between the layer of EUV resist material and the organic planarizing layer.   
     
     
         18 . The method of  claim 9 , wherein the one or more additional layers of the multi-layer stack comprises:
 an adhesion layer;   a hard mask antireflection coating layer; and   an organic planarizing layer;   wherein the adhesion layer is disposed between the layer of EUV resist material and the hard mask antireflection coating layer; and   wherein the hard mask antireflection coating layer is disposed on the organic planarizing layer.   
     
     
         19 . A semiconductor structure comprising:
 a substrate; and   a multi-layer stack disposed on the substrate, wherein the multilayer stack comprises a surface-hardened EUV resist mask formed over one or more additional layers of the multi-layer stack;   wherein the surface-hardened EUV resist mask comprises a etch-resistant layer that is embedded in the upper surface of the EUV resist mask, wherein the etch-resistant layer comprises an implanted species that is configured to one of chemically alter and structurally alter the EUV resist material to increase an etch-resistivity of the upper surface of the EUV resist mask.   
     
     
         20 . The semiconductor structure of  claim 19 , wherein the implanted species comprises one of a chemical species and a metallic species which is implanted into the upper surface of the EUV resist mask using a neutral atom beam (NAB) process.