A feature in a thin-film structure such as an AMLCD array has an edge with a tapered sidewall profile, reducing step coverage problems. The feature can be produced by producing a layer in which local etch rates vary in the thickness direction of the layer. The layer can then be etched to produce the feature with the tapered sidewall profile. The layer can be produced by physical vapor deposition. The layer can, for example, includes sublayers with different etch rates, either due to different atomic proportions of constituents or due to different etchants. Or local etch rates can vary continuously as a result of changing deposition conditions. Differences in etch rates or differences in etchant mixtures can be used to obtain a desired angle of elevation.