Abstract: A RF MOS- or nonlinear device-based surveillance and/or identification tag, and methods for its manufacture and use. The tag generally includes (a) an inductor, (b) a first capacitor plate coupled to the inductor, (c) a dielectric film on the first capacitor plate, (d) a semiconductor component on the dielectric film, and (e) a conductor that provides electrical communication between the semiconductor component and the inductor. The method of manufacture generally includes (1) depositing a semiconductor material (or precursor) on a dielectric film; (2) forming a semiconductor component from the semiconductor material/precursor; (3) forming a conductive structure at least partly on the semiconductor component; and (4) etching the electrically functional substrate to form (i) an inductor and/or (ii) a second capacitor plate.