Method for fabrication of localized plasmon transducers

Abstract

A method is presented for use in fabrication of metal islands on an oxide substrate. The method comprises: depositing a selected metal on the oxide substrate by evaporation of said selected metal; and annealing a film of the selected metal on said substrate at temperatures including an annealing temperature being less than 50° c lower than a glass transition temperature, thereby forming the metal islands partially embedded in said substrate.

1 . A structure comprising a glass substrate carrying a plurality of isolated metal islands on a surface of the glass substrate, wherein said islands are depressed into said substrate being partially embedded into said glass substrate, said metal islands being characterized by stabilized morphology and optical properties. 
     
     
         2 . A structure according to  claim 1 , wherein a majority of said islands are embedded into depressions with a rim higher than 0.5 nm. 
     
     
         3 . A structure according to  claim 1 , wherein a majority of in-plane shapes of said islands have at least one crystallographic angle. 
     
     
         4 . A structure according to  claim 1 , wherein said metal islands directly interface said substrate without an intermediate metal or organic adhesion layer. 
     
     
         5 . A structure according to  claim 3 , wherein said metal islands directly interface said substrate without an intermediate metal or organic adhesion layer. 
     
     
         6 . A structure according to  claim 1 , wherein said metal is gold. 
     
     
         7 . A structure according to  claim 1 , wherein said plurality of islands are embedded into depressions with closed-loop glass nano-sized rims on said substrate, major axis of a majority of said islands being between 5 nm and 400 nm and heights of a majority of said depressions being higher than 0.5 nm. 
     
     
         8 . A structure according to  claim 7 , wherein a majority of said rims enclose depressions with more than 0.5 nm depths, said depths being measured from main surface of said glass substrate. 
     
     
         9 . A structure according to  claim 1 , wherein said islands have substantially elongated geometry. 
     
     
         10 . A structure according to  claim 1 , wherein said glass is borosilicate glass. 
     
     
         11 . A structure according to  claim 1  being fabricated by a method comprising:
 depositing a selected metal on the glass substrate by evaporation of said selected metal; and 
 annealing a deposited film of the selected metal on said substrate, said annealing being carried out for a selected period of time and at temperatures including an annealing temperature being less than 50° C. lower than a glass transition temperature of said substrate, thereby forming the metal islands depressed into said substrate so that the metal islands become partially embedded within said substrate. 
 
     
     
         12 . A structure according to  claim 11 , wherein the annealing temperature substantially does not exceed the transition temperature by more than 100° C. 
     
     
         13 . A structure according to  claim 11 , wherein the annealing at said annealing temperature is performed with access of oxygen to said film. 
     
     
         14 . A structure according to  claim 11 , wherein said metal is gold. 
     
     
         15 . A structure according to  claim 11 , wherein said annealing is done for a time longer than 30 minutes. 
     
     
         16 . A structure according to  claim 11 , wherein said annealing is done for a time longer than three hours. 
     
     
         17 . A structure according to  claim 11 , wherein said film for more than 10% consists of islands of said metal. 
     
     
         18 . A structure according to  claim 11 , wherein the film of said metal directly interfaces with said substrate without any intermediate adhesive layer between the film and the substrate. 
     
     
         19 . A structure according to  claim 11 , wherein said annealing temperature is less than 20° C. lower than said transition temperature. 
     
     
         20 . A structure according to  claim 11 , wherein said glass is a borosilicate glass. 
     
     
         21 . A sensor device comprising the structure of  claim 1 , the sensor device being optically responsive to changes in refractive index of foreign chemical or biological material compositions to which the structure is exposed.