Metal nanodot arrays and fabrication methods thereof

Abstract

Metal nanodot arrays and fabrication methods thereof. A film of a block copolymer is deposited on a conductive substrate. The block copolymer comprises first polymer and second polymer blocks, wherein the first polymer blocks have a periodically ordered morphology. The first polymer blocks are selectively degraded to form a nanopatterned template comprising periodically ordered nanochannels. By electroplating, metal is deposited into the nanochannels that expose the conductive substrate, thus forming a metal nanodot array.

1 . A method for fabricating a metal nanodot array, comprising: 
 providing a conductive substrate;    depositing a film of a block copolymer on the conductive substrate, wherein the block copolymer comprises first polymer and second polymer blocks, the first polymer blocks forming a periodically ordered morphology;    selectively degrading the first polymer blocks to form a nanopatterned template comprising periodically ordered nanochannels exposing the conductive substrate; and    depositing metal into the nanochannels by electroplating, thereby forming the metal nanodot array.    
     
     
         2 . The method as claimed in  claim 1 , wherein the conductive -substrate comprises a non-transparent substrate.  
     
     
         3 . The method as claimed in  claim 1 , wherein the conductive substrate comprises a transparent substrate.  
     
     
         4 . The method as claimed in  claim 1 , wherein the conductive substrate comprises conductive and non-conductive areas, and the step of depositing metal comprises selectively depositing metal into the nanochannels exposing the conductive areas.  
     
     
         5 . The method as claimed in  claim 1 , wherein the conductive substrate comprises a periodic array of conductive areas.  
     
     
         6 . The method as claimed in  claim 5. , wherein the conductive areas are arranged at an interval of about 1-300 μm.  
     
     
         7 . The method as claimed in  claim 1 , wherein the metal is deposited by pulse electroplating.  
     
     
         8 . The method as claimed in  claim 7 , wherein the pulse electroplating is performed with a current on/off ratio less than 10.  
     
     
         9 . The method as claimed in  claim 1 , further comprising depositing more than one metals into the nanochannels by electroplating to form multi-level metal studs.  
     
     
         10 . The method as claimed in  claim 1 , wherein the metal comprises one or more of Ni, Co, Fe, Mo, W, Pd, or alloys thereof.  
     
     
         11 . The method as claimed in  claim 1 , further comprising forming a conductive layer overlying the nanopatterned template and the metal nanodot array.  
     
     
         12 . The method as claimed in  claim 1 , further comprising removing the nanopatterned template after forming the metal nanodot array.  
     
     
         13 . The method as claimed in  claim 12 , further comprising forming nanoscale objects using the metal nanodot array as catalyst after removing the nanopatterned template.  
     
     
         14 . The method as claimed in  claim 13 , wherein the nanoscale objects comprise carbon nanotubes (CNTs).  
     
     
         15 . The method as claimed in  claim 14 , wherein the nanopatterned template is removed by placing the substrate in a furnace at combustion atmosphere, and the carbon nanotubes are grown in-situ in the furnace at an elevated temperature.  
     
     
         16 . The method as claimed in  claim 1 , wherein the first polymer blocks form a hexagonal cylindrical morphology with its axis perpendicular to a surface of the substrate.  
     
     
         17 . The method as claimed in  claim 1 , wherein the first polymer blocks comprise poly(L-lactide), poly(D-lactide), poly(lactide), and the second polymer blocks comprise poly(styrene), poly(vinylpyridine), and poly(acrylonitrile).  
     
     
         18 . The method as claimed in  claim 1 , wherein the first polymer blocks are poly(L-lactide) and the second polymer blocks are poly(styrene).  
     
     
         19 . The method as claimed in  claim 1 , wherein the first polymer blocks are selectively degraded by hydrolysis.  
     
     
         20 . A metal nanodot array, comprising 
 a conductive substrate with conductive areas and non-conductive areas; and    a metal nanodot array selectively disposed in the conductive areas of conductive substrate.    
     
     
         21 . The metal nanodot array as claimed in  claim 20 , wherein the conductive substrate comprises a non-transparent substrate.  
     
     
         22 . The metal nanodot array as claimed in  claim 20 , wherein the conductive substrate comprises a transparent substrate.  
     
     
         23 . The metal nanodot array as claimed in  claim 20 , the conductive areas are formed as a periodic array.  
     
     
         24 . The metal nanodot array as claimed in  claim 23 , the conductive areas have an interval of about 1-300 μm.  
     
     
         25 . The metal nanodot array as claimed in  claim 20 , further comprising a nanopatterned template with periodically ordered nanochannels exposing the conductive substrate, and the metal nanodot array being disposed within the nanochannels that expose the conductive areas.  
     
     
         26 . The metal nanodot array as claimed in  claim 25 , further comprising a conductive layer overlying the nanopatterned template and the metal nanodot array.  
     
     
         27 . The metal nanodot array as claimed in  claim 20 , further comprising nanoscale objects overlying the metal nanodot array.  
     
     
         28 . The metal nanodot array as claimed in  claim 27 , wherein the nanoscale objects comprises carbon nanotubes (CNTs).  
     
     
         29 . The metal nanodot array as claimed in  claim 20 , wherein the metal nanodot array comprises multi-level metal studs formed of more than one metals.