Method for etching metal thin film consisting essentially of aluminum and for producing thin film transistor.

摘要

Metal thin film consisting essentially of aluminum is etched with an etching liquid containing at least fluoric acid and no smaller than 10% of nitric acid, and the etched metal thin film has a peripheral edge having a beveled cross-sectional profiles of the desired positive (non-overhanging) tapering angle. The buried lower-layer thin lead conductors on an insulator substrate is etched by this etching liquid, and the beveled cross-sectional profiles ensure a low reject rate of disconnection of the lead conductor in the wiring at upper layer. <IMAGE>