Display substrate, method for preparing the same, and display device

1. A method for preparing a display substrate, comprising:

forming a conductive layer;

forming a first photoresist pattern and a second photoresist pattern on the conductive layer, wherein the adhesion between the first photoresist pattern and the conductive layer is less than the adhesion between the second photoresist pattern and the conductive layer; and

etching the conductive layer by using the first photoresist pattern and the second photoresist pattern as masks to form a first conductive pattern and a second conductive pattern, respectively, wherein a line width difference between the first conductive pattern and the first photoresist pattern is greater than a line width difference between the second conductive pattern and the second photoresist pattern.

2. The method of claim 1 , wherein an orthogonal projection of the first conductive pattern on a base substrate of the display substrate falls within an orthogonal projection of the first photoresist pattern on the base substrate, and an orthogonal projection of the second conductive pattern on the base substrate of the display substrate falls within an orthogonal projection of the second photoresist pattern on the base substrate.

3. The method of claim 2 , wherein an orthogonal projection of a center axis of the first conductive pattern in an extending direction thereof on the base substrate coincides with an orthogonal projection of a central axis of the first photoresist pattern in an extending direction thereof on the base substrate.

4. The method of claim 2 , wherein an orthogonal projection of a central axis of the second conductive pattern in an extending direction thereof on the base substrate coincides with an orthogonal projection of a central axis of the second photoresist pattern in an extending direction thereof on the base substrate.

5. The method of claim 1 , wherein components of the first photoresist pattern and the second photoresist pattern comprise a base material, a photosensitive material, and a solvent material, a density of polar groups contained in the base material of a portion of the first photoresist pattern in contact with the conductive layer is greater than a density of polar groups contained in the base material of a portion of the second photoresist pattern in contact with the conductive layer.

6. The method of claim 5 , wherein the polar group is a hydroxyl group (—OH).

7. The method of claim 5 , wherein the base material in the first photoresist pattern and the second photoresist pattern is a phenol resin containing different amounts of polar groups.

8. The method of claim 1 , wherein the forming the first photoresist pattern and the second photoresist pattern on the conductive layer comprises:

coating a first photoresist layer on the conductive layer, and exposing and developing the first photoresist layer to form a second photoresist transition pattern;

coating a second photoresist layer on the conductive layer and the second photoresist transition pattern, wherein an adhesion between the first photoresist layer and the conductive layer is greater than an adhesion between the second photoresist layer and the conductive layer; and

exposing and developing the second photoresist layer to form the first photoresist pattern, wherein the second photoresist transition pattern and the second photoresist layer remaining on the second photoresist transition pattern constitute the second photoresist pattern.

9. The method of claim 1 , wherein the conductive layer is a gate metal layer, the first conductive pattern is a gate electrode of a thin film transistor, and the second conductive pattern is a gate wiring.

10. The method of claim 9 , wherein the method comprises:

forming an active layer of the thin film transistor;

forming a gate insulation layer, wherein the gate insulation layer covers the active layer;

forming the gate metal layer on the gate insulation layer;

forming the first photoresist pattern and the second photoresist pattern on the gate metal layer;

etching the gate metal layer by using the first photoresist pattern and the second photoresist pattern as masks to form the gate and the gate wiring, respectively;

etching the gate insulation layer by using the first photoresist pattern and the second photoresist pattern as masks to form a pattern of the gate insulation layer;

performing a conductorization process on the active layer using the first photoresist pattern as a mask; and

removing the first photoresist pattern and the second photoresist pattern.

11. The method of claim 1 , wherein a line width difference between the first conductive pattern and the first photoresist pattern is 1.5 μm to 2.5 μm, and a line width difference between the second conductive pattern and the second photoresist pattern is 0.5 μm to 1.2 μm.

12. A display substrate, prepared by the method of claim 1 .

13. The display substrate of claim 12 , wherein the first conductive pattern is a gate electrode of a thin film transistor, and the second conductive pattern is a gate wiring.

14. The display substrate of claim 12 , wherein an orthogonal projection of the gate electrode of the thin film transistor on the base substrate of the display substrate falls within an orthogonal projection of the gate insulation layer of the thin film transistor on the base substrate.

15. A display device, comprising the display substrate of claim 12 .

16. The method of claim 5 , wherein the polar group is a carboxyl group (—COOH).

17. The method of claim 5 , wherein the polar group is a hydroxyl group (—OH) and a carboxyl group (—COOH).