| abstract |
The etchant, comprises hydrogen peroxide (H2O2); and at least one e.g. in a mixed solution of an organic acid, an inorganic acid, and a neutral salt, optionally with a stabiliser. The etchant is used to etch a double-layered metal layer which can include copper or a copper alloy and a molybdenum layer of an array substrate in a thin film transistor liquid crystal display device. |