An exemplary thin film transistor array substrate (200) includes a substrate (210) and a gate electrode (220) formed on the substrate. The gate electrode includes an adhesive layer (226) formed on the substrate, a conductive layer (224) formed on the adhesive layer and a barrier layer (222) formed on the conductive layer, the adhesive layer and the barrier layer both have sandwich structures. A central core of the adhesive layer, the conductive layer, and a central core of the barrier layer are made of a same material.