Methods For Dual-Scale Surface Texturing

Abstract

Methods for preparing a substrate surface are provided, for purposes including manufacturing a low reflectivity surface. In some aspects, the methods include providing a material comprising an etching mask on a substrate, subjecting the material to a first isotropic etching phase, and subjecting the material to a first anisotropic etching phase, thereby forming a textured surface on the material, wherein the textured surface comprises structures with dimensions in a sub-micron range.

What is claimed is: 
     
         1 . A method of preparing a substrate surface, the method comprising:
 (a) providing a material comprising an etching mask on a substrate;   (b) subjecting the material to a first isotropic etching phase; and   (c) subjecting the material to a first anisotropic etching phase,   thereby forming a textured surface on the material, wherein the textured surface comprises structures with dimensions in a sub-micron range.   
     
     
         2 . The method of  claim 1 , wherein at least one of the first isotropic etching phase and first anisotropic etching phase comprises reactive ion etching. 
     
     
         3 . The method of  claim 1 , the method further comprising generating a plasma. 
     
     
         4 . The method of  claim 1 , wherein the structures include nano-scale structures disposed on micro-scale structures. 
     
     
         5 . The method of  claim 1 , further comprising subjecting the material to a second isotropic etching phase or a second anisotropic etching phase, or both. 
     
     
         6 . The method of  claim 1 , wherein the textured surface further comprises silicon nano-structures. 
     
     
         7 . The method of  claim 1 , wherein the textured surface further comprises spiked nano-rod structures. 
     
     
         8 . The method of  claim 1 , wherein the textured surface further comprises a substantially uniform array or a substantially ordered array, or both. 
     
     
         9 . The method of  claim 1 , wherein the structures are selected from the group consisting of rods, cones, frustums, pyramids and needles. 
     
     
         10 . The method of  claim 1 , wherein the textured surface is formed to exhibit a weighted reflectance of less than 5% over a wavelength range of about 300 nanometers to about 1100 nanometers. 
     
     
         11 . A method of preparing a substrate surface, the method comprising:
 (a) dispersing a plurality of particles in a suspending medium to form a suspension;   (b) spin-coating the suspension on a substrate comprising a material to form an etching mask on the substrate;   (c) subjecting the material to a first isotropic etching phase, using the etching mask, forming a modified etching mask; and   (d) subjecting the material to a first anisotropic etching phase, using the modified etching mask,   thereby forming a textured surface on the material, wherein the textured surface comprises structures with dimensions in a sub-micron range.   
     
     
         12 . The method of  claim 11 , wherein the plurality of particles comprises colloidal particles. 
     
     
         13 . The method of  claim 11 , wherein the suspending medium is selected from a group consisting of tetrahydrofuran, ethyl acetate, acetone, dimethylformamide, acetonitrile, dimethyl sulfoxide, and mixtures thereof. 
     
     
         14 . The method of  claim 11 , the method further comprising generating a plasma. 
     
     
         15 . The method of  claim 11 , wherein the structures include nano-scale structures disposed on micro-scale structures. 
     
     
         16 . The method of  claim 11 , further comprising subjecting the material to a second isotropic etching phase or a second anisotropic etching phase, or both. 
     
     
         17 . The method of  claim 11 , wherein the textured surface further comprises spiked nano-rod structures. 
     
     
         18 . The method of  claim 11 , wherein the textured surface further comprises a substantially uniform array or a substantially ordered array, or both. 
     
     
         19 . The method of  claim 11 , wherein the structures are selected from the group consisting of rods, cones, frustums, pyramids and needles. 
     
     
         20 . The method of  claim 11 , wherein the textured surface is formed to exhibit a weighted reflectance of less than 5% over a wavelength range of about 300 nanometers to about 1100 nanometers.