1. A process for creating in a substrate a grayscale feature and a micromachined alignment feature from a single exposure mask comprising: providing a protective layer over a first surface of the substrate at a selected location of a substrate alignment feature; providing a photosensitive material layer over the protective layer and over an exposed portion of the first substrate surface; exposing the photosensitive material layer with light through an exposure mask having a grayscale pattern and an alignment pattern; processing the photosensitive material layer to produce a replica of the grayscale pattern within the photosensitive material layer and to produce a micromachined feature aperture corresponding to the alignment pattern within the photosensitive material; removing a portion of the protective layer within the micromachined feature aperture to create a protective layer cavity at the desired location of the micromachined feature; transferring the grayscale pattern present in the photosensitive material layer to the substrate to create a grayscale feature in the substrate; providing a feature-protection layer over the grayscale feature and the protective layer; providing a barrier layer over the feature-protection layer with an opening overlapping the protective layer cavity; removing a portion of the feature-protection layer from within the opening; removing the barrier layer; removing the remaining portion of the protective layer within the protective layer cavity; and removing a portion of the substrate within the protective layer cavity to create the micromachined feature in the substrate.