NOVELTY - Manufacture of a transparent zinc-oxide-based thin film transistor comprises patterning a transparent zinc-oxide semiconductor material to form a semiconductor thin film element in which a spacing provided by a passivation structure dimensionally defines a channel in the semiconductor thin film element that is aligned with a non-transmissive gate structure, where semiconductor channel comprises parallel elongated sides that are aligned with parallel elongated sides of non-transmissive gate structure via alignment with elongated parallel walls of passivation structure.    USE - Method of manufacturing a transparent zinc-oxide-based thin film transistor useful for an electronic device i.e. integrated circuit, active-matrix display, optoelectronic display device comprising active-matrix LCD, solar cell, flat panel display, active matrix imager, sensor, radio frequency label containing price, identification, and/or inventory information (all claimed).    ADVANTAGE - The method can be accomplished while maintaining the substrate temperature at not greater than 300 degrees C during fabrication. It facilitates accurate alignment of the source and drain with respect to the gate, in a simple way at low cost; and provides semiconductor films capable of exhibiting, in the film form, stable threshold voltages and excellent field-effect electron mobility of greater than 0.01 cm2/Vs and on-off ratios of greater than 104.    DETAILED DESCRIPTION - Manufacture of a transparent zinc-oxide-based thin film transistor supported on a substrate having two sides, where substrate is transmissive to a preselected spectrum of actinic radiation, comprises:    (A) depositing on the first side of the substrate a non-transmissive first conductive material to form a non-transmissive gate structure that is not transmissive to the preselected spectrum of actinic radiation;    (B) depositing over the non-transmissive gate structure dielectric material to form a dielectric layer;    (C) depositing transparent zinc-oxide-based semiconductor material over the dielectric layer, vertically spaced from the non-transmissive gate structure by the dielectric layer;    (D) applying a layer of positive-working photoresist material over the first side of the substrate, over the semiconductor thin film, and then exposing the photoresist material to the preselected spectrum of actinic radiation from its source through the second side of the substrate, where non-transmissive gate structure masks the actinic radiation, forming an exposed area of photoresist material not blocked by the non-transmissive gate structure;    (E) developing the exposed photoresist to form a patterned passivation structure comprising parallel elongated walls vertically aligned with parallel elongated sides of the non-transmissive gate structure;    (F) depositing a second conductive material to form a source electrode and a drain electrode, where source and drain electrodes are positioned over, and in electrical contact with, the semiconductor thin film and horizontally separated from each other by a spacing provided by the passivation structure; and    (G) patterning the transparent zinc-oxide semiconductor material to form a semiconductor thin film element in which the spacing provided by the passivation structure dimensionally defines a channel in the semiconductor thin film element that is aligned with the non-transmissive gate structure, where semiconductor channel comprises parallel elongated sides that are aligned with the parallel elongated sides of the non-transmissive gate structure via the alignment with the elongated parallel walls of the passivation structure.    INDEPENDENT CLAIMS are included for:    (1) thin film transistors; and    (2) an optoelectronic display device.    DESCRIPTION OF DRAWING(S) - The drawing is a flow diagram of a method for manufacturing a transparent zinc-oxide-based thin film transistor.