In-Situ Deposition and Densification Treatment for Metal-Comprising Resist Layer

Abstract

Metal-comprising resist layers (for example, metal oxide resist layers), methods for forming the metal-comprising resist layers, and lithography methods that implement the metal-comprising resist layers are disclosed herein that can improve lithography resolution. An exemplary method includes forming a metal oxide resist layer over a workpiece by performing deposition processes to form metal oxide resist sublayers of the metal oxide resist layer over the workpiece and performing a densification process on at least one of the metal oxide resist sublayers. Each deposition process forms a respective one of the metal oxide resist sublayers. The densification process increases a density of the at least one of the metal oxide resist sublayers. Parameters of the deposition processes and/or parameters of the densification process can be tuned to achieve different density profiles, different density characteristics, and/or different absorption characteristics to optimize patterning of the metal oxide resist layer.

What is claimed is: 
     
         1 . A metal oxide resist layer comprising:
 a first metal oxide resist sublayer having a first density;   a second metal oxide resist sublayer disposed over the first metal oxide resist sublayer, wherein the second metal oxide resist sublayer has a second density; and   a third metal oxide resist sublayer disposed over the second metal oxide resist sublayer, wherein the third metal oxide resist sublayer has a third density.   
     
     
         2 . The metal oxide resist layer of  claim 1 , wherein the first density, the second density, and the third density are substantially the same. 
     
     
         3 . The metal oxide resist layer of  claim 1 , wherein the first density, the second density, and the third density are different. 
     
     
         4 . The metal oxide resist layer of  claim 1 , wherein the first density, the second density, and the third density are configured to provide the metal oxide resist layer with a gradient density from the first metal oxide resist sublayer to the third metal oxide resist sublayer. 
     
     
         5 . The metal oxide resist layer of  claim 1 , wherein the first density and the third density are each less than the second density. 
     
     
         6 . The metal oxide resist layer of  claim 1 , wherein the first density and the third density are each greater than the second density. 
     
     
         7 . The metal oxide resist layer of  claim 1 , wherein each of the first metal oxide resist sublayer, the second metal oxide resist sublayer, and the third metal oxide resist sublayer have an atomic structure that includes metal-and-oxygen constituents stacked in an ordered arrangement. 
     
     
         8 . The metal oxide resist layer of  claim 7 , wherein the metal-and-oxygen constituents include 12-MeO x  clusters, 8-MeO x  clusters, 6-MeO x  clusters, 4-MeO x  clusters, dimer-MeO x  clusters, mono-MeO x  clusters, or a combination thereof, wherein Me is metal, O is oxygen, and x is a number of oxygen atoms. 
     
     
         9 . A metal oxide resist layer comprising:
 a first metal oxide photosensitive material, a second metal oxide photosensitive material, and a third metal oxide photosensitive material sequentially stacked;   wherein the first metal oxide photosensitive material has a first density, the second metal oxide photosensitive material has a second density, and the third metal oxide photosensitive material has a third density, wherein the first density is different than the second density and the second density is different than the third density; and   wherein the first metal oxide photosensitive material has a first thickness, the second metal oxide photosensitive material has a second thickness, and the third metal oxide photosensitive material has a third thickness.   
     
     
         10 . The metal oxide resist layer of  claim 9 , wherein the first density is greater than the second density, and the second density is greater than the third density. 
     
     
         11 . The metal oxide resist layer of  claim 9 , wherein the first density is less than the second density, and the second density is less than the third density. 
     
     
         12 . The metal oxide resist layer of  claim 9 , wherein the first density is less than the second density, and the second density is greater than the third density. 
     
     
         13 . The metal oxide resist layer of  claim 9 , wherein the first density is greater than the second density, and the second density is less than the third density. 
     
     
         14 . The metal oxide resist layer of  claim 9 , wherein the first density is less than the second density and the third density. 
     
     
         15 . The metal oxide resist layer of  claim 9 , wherein concentrations of metal oxide clusters in the first metal oxide photosensitive material, the second metal oxide photosensitive material, and the third metal oxide photosensitive material are different to provide the first density, the second density, and the third density. 
     
     
         16 . The metal oxide resist layer of  claim 9 , wherein the first thickness, the second thickness, and the third thickness are different. 
     
     
         17 . A metal oxide resist layer comprising:
 a photosensitive metal oxide material having an atomic structure that includes metal-and-oxygen (MeO) constituents stacked in an ordered arrangement; and   wherein the photosensitive metal oxide material has at least two different densities along a thickness of the photosensitive metal oxide material.   
     
     
         18 . The metal oxide resist layer of  claim 17 , wherein the metal-and-oxygen constituents include metal oxide clusters, and a first concentration of the metal oxide clusters at a bottom of the photosensitive metal oxide material is different than a second concentration of the metal oxide clusters at a top of the photosensitive metal oxide material to provide the photosensitive metal oxide material with the at least two different densities along the thickness. 
     
     
         19 . The metal oxide resist layer of  claim 17 , wherein a first density at a top of the photosensitive metal oxide material is greater than a second density at a bottom of the photosensitive metal oxide material. 
     
     
         20 . The metal oxide resist layer of  claim 17 , wherein the metal is Sn, Bi, Sb, In, Te, Ti, Zr, Hf, V, Co, Mo, W, Al, Ga, Si, Ge, P, As, Y, La, Ce, or Lu.