NOVELTY - Selectively patterning a three-dimensional structure comprising spaced elements involves embedding a portion of the three-dimensional structure with a material filling a space within the elements, where the material is polymer (710) or wax, and defines an embedded portion of the three-dimensional structure and an unembedded portion of the three-dimensional structure; and patterning the unembedded portions of the elements, thus selectively patterning the three-dimensional structure.    USE - For selectively patterning three-dimensional structures (claimed), such as semiconductor microstructures, particularly silicon wire arrays.    ADVANTAGE - The patterning involves application of a functional coating (e.g. a methyl termination), depositing a semiconductor (e.g. amorphous silicon), and/or depositing an insulator (e.g. silicon nitride) on the top portion of the wires. The patterning also involves adding a functional element to the space between the top regions or portions of the wires, e.g. dielectric scattering particles are added, followed by an infilling with polymer and inversion of the structure, in order to obtain a polymer embedded silicon wire array with dielectric scattering particles located only at a base of the wire array. Such structure minimizes or eliminates reflection losses that occur if dielectric scattering particles were located at the top of the wire array.    DETAILED DESCRIPTION - Selectively patterning a three-dimensional structure comprising spaced elements involves embedding a portion of the three-dimensional structure with a material filling a space within the elements, where the material is polymer (710) or wax, and defines an embedded portion of the three-dimensional structure and an unembedded portion of the three-dimensional structure; and patterning the unembedded portions of the elements, thus selectively patterning the three-dimensional structure. The patterning involves etching and/or deposition. The embedding steps proceed in a bottom-to-top direction of the three-dimensional structure. The elements are microscale or nanoscale silicon wires. The silicon wires are doped with a first type of dopant and the patterning forms regions of a second type of dopant around the uncovered portions of the doped silicon wires. The patterning involves at least one of: removing the coating from the top regions of the wires, applying a functional coating to the top regions of the wires, depositing a semiconductor to the top regions of the wires, and depositing an insulator to the top regions of the wires; and adding a functional element to the space between the top regions of the wires. The functional element comprises dielectric scattering particles. The method further involves embedding the patterned portions of the microscale or nanoscale wires with a material filling a space between the patterned portions; and inverting the structure thus obtained. INDEPENDENT CLAIMS are included for the following:    (1) forming radial and axial junctions in a silicon microscale or nanoscale wire array, involving providing a silicon wire array; doping the silicon wire array with a first type of dopant; covering the silicon wire array with oxide to form an oxide covered silicon wire array; applying a polymer to the oxide covered silicon wire array; forming on each wire a first region where the wire is covered with the oxide and the polymer, and a second region where the wire and oxide are exposed; removing the exposed oxide from the second region without removing the polymer protected oxide from the first region; removing the polymer; and doping the second regions of the silicon wire array with a second type of dopant different from the first type of dopant, forming radial junctions between the first type of dopant in the second region and the second type of dopant in the second region of the wires; and    (2) a silicon microscale or nanoscale wire solar cell, comprising: aligned microscale or nanoscale wires embedded into polymer; light scattering particles (720, 740) embedded into the polymer between the wires; a first contact; and a second contact, the second contact acting as a back reflector.    DESCRIPTION OF DRAWING(S) - The figure shows steps of patterning a three-dimensional structure.    Polymer (710)    Aluminum material (720, 740)    Second layer of polymer (730)