Nanoscale Etching of Light Absorbing Materials using Light and an Electron Donor Solvent

Abstract

A method for etching a light absorbing material permits directly writing a pattern of etching of silicon nitride and other light absorbing materials, without the need of a lithographic mask, and allows the creation of etched features of less than one micron in size. The method can be used for etching deposited silicon nitride films, freestanding silicon nitride membranes, and other light absorbing materials, with control over the thickness achieved by optical feedback. The etching is promoted by solvents including electron donor species, such as chloride ions. The method provides the ability to etch silicon nitride and other light absorbing materials, with fine spatial and etch rate control, in mild conditions, including in a biocompatible environment. The method can be used to create nanopores and nanopore arrays.

What is claimed is: 
     
         1 . An apparatus comprising a light absorbing material, the apparatus comprising:
 an etched feature comprising a nanopore through the light absorbing material, the nanopore having a diameter greater than about 1 nanometer and less than about 1 micron;   wherein the nanopore has a greater diameter on one side of the light absorbing material than on an opposite side of the light absorbing material.   
     
     
         2 . The apparatus of  claim 1 , wherein the light absorbing material comprises a thickness less than about 1 micron at the location of the nanopore. 
     
     
         3 . The apparatus of  claim 1 , comprising an array of a plurality of nanopores.