Array substrate and its fabricating method, display device

A method for fabricating an array substrate, comprising:

• forming a pattern comprising a light shading member on a transparent substrate;
• spreading an organic material solution at least partially on the light shading member;
• solidifying the organic material solution, to form a buffer layer on the light shading member;
• forming a first via hole on the buffer layer, to expose part of the light shading member;
• forming a pattern of an active layer on the buffer layer, wherein the active layer is above the light shading member;
• and
• forming a gate pattern, wherein the gate pattern is disposed on the active layer and is insulated from the active layer,
• wherein the active layer comprises a channel region that corresponds to the gate pattern and a source contact region and a drain contact region that are located on two sides of the channel region, and
• after the step of forming the gate pattern, the method further comprises:
• forming an interlayer dielectric layer;
• forming on the interlayer dielectric layer a second via hole, a third via hole and a fourth via hole that penetrate throughout the interlayer dielectric layer;
• wherein, the second via hole exposes at least part of the source contact region, the third via hole exposes at least part of the drain contact region, and a position of the fourth via hole corresponds to a position of the first via hole, to expose part of the light shading member;
• and
• forming a pattern comprising a source and a drain, wherein the source is connected to the source contact region by the second via hole, and the drain is connected to the drain contact region by the third via hole, and is connected to the light shading member by the fourth via hole.