Array substrate, method for manufacturing the same, and display device

A method for manufacturing an array substrate, comprising a step:

• (1) sequentially forming a first adhesion enhancement layer, a first copper-bearing metal layer and a photoresist layer on a substrate, and respectively forming a reserved region and a removal region by performing exposure and development on the photoresist layer using a mask plate, wherein the reserved region corresponds to a pattern forming region;
• simultaneously processing the first adhesion enhancement layer, the first copper-bearing metal layer and the photoresist layer in the removal region by a single wet etching process to completely remove the first adhesion enhancement layer, the first copper-bearing metal layer, and the photoresist layer in the removal region, thus forming a first adhesion enhancement intermediate layer corresponding to the first adhesion enhancement layer, a first copper-bearing metal intermediate layer corresponding to the first copper-bearing metal layer, and the photoresist layer on the first copper-bearing metal intermediate layer in the reserved region, wherein the width of the formed first adhesion enhancement intermediate layer is larger than the width of the formed first copper-bearing metal intermediate layer, so that the first adhesion enhancement intermediate layer forms a step structure with respect to the first copper-bearing metal intermediate layer;
• and simultaneously processing the first adhesion enhancement intermediate layer, the first copper-bearing metal intermediate layer and the photoresist layer thereon in the reserved region by a dry etching process to remove the step structure, then stripping off the photoresist layer, to form a patterned first adhesion enhancement layer and a patterned first copper-bearing metal layer respectively, wherein the first adhesion enhancement layer is a metal layer for enhancing adhesion of the first copper-bearing metal layer to the substrate.