Depositing nano-dots on a substrate

Abstract

A method of depositing nano-dots on a substrate includes forming a template on the base, the template defining nano-pores, at least partially filling the nano-pores with a pillar material to define nano-pillars, depositing a dot material on the nano-pillars to define nano-dots on the nano-pillars, and contact printing the substrate with the array of nano-dots.

What is claimed is: 
     
         1 . A method of depositing nano-dots on a substrate, the method comprising comprising:
 forming a template on the base, the template defining nano-pores;   at least partially filling the nano-pores with a pillar material to define nano-pillars;   depositing a dot material on the nano-pillars to define nano-dots on the nano-pillars; and   contact printing the substrate with the array of nano-dots.   
     
     
         2 . The method of  claim 1 , wherein the pillar material is deposited to define an array of nano-pillars of substantially uniform height. 
     
     
         3 . The method of  claim 2 , wherein the dot material is deposited to define an array of nano-dots of substantially uniform height. 
     
     
         4 . The method of  claim 3 , wherein the nano-pillars are deposited to a pillar height and the nano-dots are deposited to a dot height, the pillar height being greater than the dot height. 
     
     
         5 . The method of  claim 3 , wherein the nano-pillars have a pillar thickness and the nano-dots have a dot thickness substantially the same as the pillar thickness. 
     
     
         6 . The method of  claim 1 , wherein the pillar material is tantalum pentoxide (Ta 2 O 5 ). 
     
     
         7 . The method of  claim 1 , wherein the dot material is electrochemically deposition on the pillar material. 
     
     
         8 . The method of  claim 1 , wherein the dot material is Ni, Ag, Au, CdSe, ZnSe and ZnS. 
     
     
         9 . A method of depositing nano-dots on a substrate having a substrate surface, the method comprising:
 forming a template on a base, the template defining an array of substantially uniform nano-pores;   at least partially filling the nano-pores with pillar material to define an array of substantially uniform nano-pillars on the base;   depositing dot material on the nano-pillars to define an array of substantially uniform nano-dots on the nano-pillars;   bringing the base and substrate together to place the nano-dots into substantially uniform contact with the substrate surface; and   separating the base and substrate, the nano-dots separating from the nano-pillars and adhering to the substrate surface to leave the nano-dots on the substrate surface.   
     
     
         10 . The method of  claim 9 , wherein at least partially filling the nano-pores includes:
 forming a layer of a first oxidizable material; and   anodizing the layer of first oxidizable material to grow oxide from the first oxidizable material into the nano-pores.   
     
     
         11 . The method of  claim 10 , wherein depositing dot material on the nano-pillars includes electrochemically depositing dot material on the nano-pillars. 
     
     
         12 . The method of  claim 11 , wherein electrochemically depositing the dot material on the nano-pillars includes using the nano-pillars as a cathode. 
     
     
         13 . The method of  claim 9 , wherein forming a template includes:
 forming a layer of a second oxidizable material; and   anodizing the layer of second oxidizable material to define the nano-pores.   
     
     
         14 . The method of  claim 9 , which further comprises removing the template. 
     
     
         15 . A method of depositing nano-dots on a substrate having a substrate surface, the method comprising:
 depositing a first oxidizable material onto a base;   depositing a second oxidizable material onto the first oxidizable material;   anodizing the second oxidizable material to form a porous oxide having nano-pores that extend through the porous oxide to expose portions of the first oxidizable material;   anodizing the first oxidizable material so as to partially fill the nano-pores in the porous oxide with a pillar material including an oxide of the first oxidizable material, thereby forming an array of nano-pillars of substantially uniform height on the base;   electrochemically depositing a dot material on the nano-pillars so as further fill the nano-pores in the porous oxide with a dot material different from the pillar material;   removing porous oxide by selective etching, thereby yielding a substantially planar array of nano-dots on nano-pillars;   bringing the base and substrate together to place the array of nano-dots into substantially uniform contact with the substrate surface; and   separating the base and substrate, the nano-dots separating from the nano-pillars and adhering to the substrate surface to leave the array of nano-dots on the substrate surface.