Optical air slit and method for manufacturing optical air slits

Abstract

A structure having an optical slit therein. The structure includes a substrate having an opening therethrough and a metal layer disposed on the substrate, such metal layer having a photolithographically formed slit therein, such slit being narrower than the opening and being disposed over the opening, portions of the metal layer disposed adjacent the slit being suspended over the opening and other portions of the metal layer being supported by the substrate.

What is claimed is: 
     
         1 . A method for forming a structure having an optical slit therein, comprising;
 forming an opening through a portion of a substrate;   filling the opening with a sacrificial material, such material extending through a portion of the opening with portion of the material being disposed onto adjacent portions of an upper surface of the substrate;   polishing the sacrificial material to remove the portions of the sacrificial material disposed onto adjacent portions of the upper surface of the substrate;   forming a metalized layer on the upper surface of the substrate and the polished sacrificial material;   applying a photolithographically processable material on an upper surface of the metalized layer;   photolithographically forming a slit in the photolithographically processable material to expose a portion of the upper surface of the metallized layer, such slit being disposed over the opening in the portion of the substrate;   etching to remove the exposed portion of the upper surface of the metaled layer to expose the sacrificial material while retaining unexposed portions of the metallized layer;   removing the sacrificial layer and the photolithographically processable material.   
     
     
         2 . The method recited in  claim 1  including electroplating the unexposed portions of the metallized layer to a predetermined thickness. 
     
     
         3 . The method recited in  claim 2  wherein the electroplating is performed prior to the forming of the slit. 
     
     
         4 . The method recited in  claim 2  wherein the electroplating is performed subsequent to forming of the slit. 
     
     
         5 . The method recited in  claim 1  wherein the opening is formed using laser cutting. 
     
     
         6 . A structure having an optical slit therein, comprising:
 a substrate having an opening therethrough;   a metal layer disposed on the substrate, such metal layer having a slit therein, such slit being narrower than the opening and being disposed over the opening, portions of the metal layer disposed adjacent the slit being suspended over the opening and other portions of the metal layer being supported by the substrate.