摘要 |
Optical gratings are fabricated on a scale that may be smaller than the resolution of the lithographic system used to generate the grating pattern. Parallel ridges are formed using lithographic techniques. A conformal deposition and anisotropic etch are then used to form sidewalls on the sides of the ridges. After removing the ridges, the remaining sidewalls are used as a mask to etch the substrate. Removing the sidewalls leaves the desired grating pattern, with a pitch spacing of one-half that of the original ridges.
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