Generating an alignment signal for alignment of features in a layer of a substrate as part of a semiconductor manufacturing process is described. The present systems and methods can be faster and/or generate more information than typical methods for generating alignment signals because they utilize one or more existing structures in a patterned semiconductor wafer instead of a dedicated alignment structure. A feature (not a dedicated alignment mark) of the patterned semiconductor wafer is continuously scanned, where the scanning includes: continuously irradiating the feature with radiation; and continuously detecting reflected radiation from the feature. The scanning is performed perpendicular to the feature, along one side of the feature, or along both sides of the feature.