Method for manufacturing a flat-panel display

摘要

A liquid crystal display having a gate insulating film of whose dielectric constant is a high and exhibits excellent leakage characteristics, includes a plurality of gate wirings formed on the transparent substrate, a plurality of signal lines arrayed to intersect the plurality of gate wirings, a plurality of switching devices located at the point of intersection between the respective gate wirings and signal lines. The switching device comprises a gate electrode constituted by aluminum or an aluminum alloy and a gate insulating film inserted between the channels of switching devices and the gate electrode. The gate insulating film has a first anodic oxide film constituted by aluminum or an aluminum alloy and a second anodic oxide film constituted by tantalum or a tantalum alloy. In the manufacturing method thereof, metals, aluminum or tantalum, are simultaneously anodically oxidized so as to suppress a hillock. An insulating layer having a high dielectric constant can be easily obtained while a leakage current characteristic is strengthened and its breakdown voltage is improved. A glass substrate can be protected since second and third anodic oxide films (Ta2O5) are formed on the entire surface of the substrate.