Thin film transistor array substrate and manufacturing method thereof

A thin film transistor array substrate is discussed. The thin film transistor array substrate includes, according to one embodiment, gate and data lines crossing each other, a gate insulation film, a gate electrode, an active layer, an etch stop layer formed on the active layer to define a channel region of the active layer, and a source electrode and a drain electrode formed on the active layer. The etch stop layer is between the source and drain electrodes spaced apart from the etch stop layer. The source electrode and the drain electrode include a first electrode layer and a second electrode layer disposed on the first electrode. The first electrode layer is formed from a dry-etchable material and the second electrode layer is formed from a wet-etchable material.