A method for non-conformally coating nanometer-sized surface structures includes directing the overcoat material at an oblique angle onto a substrate having a nanometer-sized surface structure so that the overcoat material is only deposited substantially on the top portions of the nanometer-sized surface structures without filling the gaps between the nanometer-sized surface structures. Because the overcoat material is deposited onto the nanometer-sized surface structures obliquely, the overcoat material gradually closes the gaps between the nanometer-sized surface structures and form a continuous layer over the nanometer-sized surface structures.