Multi-level optical structure and method of manufacture

摘要

A multi-level optical device includes a substrate having a baseline level. At least one feature is disposed at a level above the baseline level. At least one feature is disposed at a level below the baseline level, or in the feature above the baseline level is located at a distance apart from the feature below the baseline level. The distance has an accuracy inn the range of approximately ±0.05 mum to less than approximately ±1.0 mum. A method of fabricating an optical device includes forming at least one feature at a level of above a baseline level of a substrate; and forming at least one feature at a baseline level below the baseline level of the substrate, wherein the feature at a level above the baseline level and the feature at a level below the baseline level are patterned in a single-mask step using a multi-level mask.