Array substrate, manufacturing method thereof and display device

1. An array substrate, comprising a base substrate, an active layer, a gate insulating layer and a gate electrode layer formed sequentially on the base substrate; wherein the active layer comprises a first heavily-doped region, a first lightly-doped region, a first non-doped region, a second lightly-doped region, a second non-doped region, a third lightly-doped region and a second heavily-doped region which are sequentially arranged in a horizontal direction;

wherein a projection of a pattern of the gate electrode layer onto the array substrate covers projections of the first lightly-doped region, the first non-doped region, the second lightly-doped region, the second non-doped region and the third lightly-doped region onto the array substrate; and

wherein the projection of the pattern of the gate electrode layer onto the array substrate only covers the projections of the first lightly-doped region, the first non-doped region, the second lightly-doped region, the second non-doped region and the third lightly-doped region onto the array substrate.

2. The array substrate according to claim 1 , wherein the second lightly-doped region is arranged in a middle of the active layer in the horizontal direction.

3. The array substrate according to claim 1 , further comprising a first insulating layer arranged between the base substrate and the active layer.

4. The array substrate according to claim 1 , further comprising:

a second insulating layer arranged on the gate insulating layer and the gate electrode layer;

a source-drain electrode layer arranged on the second insulating layer; wherein the source-drain electrode layer comprises a source electrode line and a drain electrode line, the source-drain electrode layer is electrically connected to the first heavily-doped region through a first via-hole passing through the second insulating layer and the gate insulating layer, and the drain electrode line is electrically connected to the second heavily-doped region through a second via-hole passing through the second insulating layer and the gate insulating layer;

a passivation layer arranged on the source-drain electrode layer; and

a pixel electrode layer arranged on the passivation layer and electrically connected to the drain electrode line through a third via-hole in the passivation layer.

5. The array substrate according to claim 4 , further comprising a protection layer arranged on the passivation layer and the pixel electrode layer, and a common electrode layer arranged on the protection layer.

6. The array substrate according to claim 1 , wherein the first lightly-doped region, the second lightly-doped region and the third lightly-doped region are each of a length of 1 μm to 3 μm; and an ion injection concentration for each of the first lightly-doped region, the second lightly-doped region and the third lightly-doped region is 5×10 11 ions/cm 2 to 1×10 14 ions/cm 2 .

7. The array substrate according to claim 1 , wherein an ion injection concentration for each of the first heavily-doped region and the second heavily-doped region is 1×10 14 ions/cm 2 to 1.5×10 20 ions/cm 2 ; and the first heavily-doped region and the second heavily-doped region are each of a length of 2 μm to 5 μm.

8. A display device comprising the array substrate according to claim 1 .

9. A method for manufacturing an array substrate, comprising:

forming patterns of an active layer, a gate insulating layer and a gate electrode layer sequentially on a base substrate; wherein the active layer comprises a first heavily-doped region, a first lightly-doped region, a first non-doped region, a second lightly-doped region, a second non-doped region, a third lightly-doped region and a second heavily-doped region which are sequentially arranged in a horizontal direction;

wherein the step of forming the patterns of the active layer, the gate insulating layer and the gate electrode layer sequentially on the base substrate comprises:

depositing an a-Si film onto the base substrate, and after the a-Si film is crystallized, forming silicon islands of the active layer by a patterning process;

applying a photoresist onto the silicon islands, and forming a plurality of gaps in the photoresist by a patterning process in such a manner that the plurality of gaps are located above positions in the silicon islands where the first lightly-doped region, the second lightly-doped region and the third lightly-doped region are located, respectively;

injecting ions at the positions in the silicon islands where the first lightly-doped region, the second lightly-doped region and the third lightly-doped region are located, respectively, through the plurality of gaps, thereby forming the first lightly-doped region, the second lightly-doped region and the third lightly-doped region of the active layer;

depositing a gate insulating layer film and a gate electrode layer film sequentially onto the silicon islands, and forming the patterns of the gate insulating layer and the gate electrode layer by a patterning process;

wherein a projection of the pattern of the gate electrode layer onto the array substrate covers projections of the first lightly-doped region, the first non-doped region, the second lightly-doped region, the second non-doped region and the third lightly-doped region onto the array substrate, and wherein the projection of the pattern of the gate electrode layer onto the array substrate only covers the projections of the first lightly-doped region, the first non-doped region, the second lightly-doped region, the second non-doped region and the third lightly-doped region onto the array substrate; and

injecting ions at positions in the silicon islands where the first heavily-doped region and the second heavily-doped region are located, respectively, thereby forming the first heavily-doped region and the second heavily-doped region of the active layer.

10. The method according to claim 9 , wherein the second lightly-doped region is arranged in a middle of the active layer in the horizontal direction.

11. The method according to claim 9 , wherein before the step of forming the patterns of the active layer, the gate insulating layer and the gate electrode layer sequentially onto the base substrate, the method further comprises: forming a pattern of a first insulating layer on the base substrate, the pattern of the active layer being arranged on the first insulating layer.

12. The method according to claim 9 , further comprising:

forming a pattern of a second insulating layer on the gate insulating layer and the gate electrode layer;

forming a first via-hole and a second via-hole in the second insulating layer and the gate insulating layer in such a manner that the first via-hole is located above the first heavily-doped region and the second via-hole is located above the second heavily-doped region;

forming a source-drain electrode layer on the second insulating layer in such a manner that the source-drain electrode layer comprises a source electrode line electrically connected to the first heavily-doped region through the first via-hole, and a drain electrode line electrically connected to the second heavily-doped region through the second via-hole;

forming a pattern of a passivation layer on the source-drain electrode layer in such a manner that the pattern of the passivation layer is provided with a third via-hole; and

forming a pattern of a pixel electrode layer on the passivation layer in such a manner that the pixel electrode layer is electrically connected to the drain electrode line through the third via-hole.

13. The method according to claim 12 , further comprising:

forming a pattern of a protection layer on the passivation layer and the pixel electrode layer; and

forming a pattern of a common electrode layer on the protection layer.

14. The method according to claim 9 , wherein the first lightly-doped region, the second lightly-doped region and the third lightly-doped region are each of a length of 1 μm to 3 μm; and an ion injection concentration for each of the first lightly-doped region, the second lightly-doped region and the third lightly-doped region is 5×10 11 ions/cm 2 to 1×10 14 ions/cm 2 .

15. The method according to claim 9 , wherein an ion injection concentration for each of the first heavily-doped region and the second heavily-doped region is 1×10 14 ions/cm 2 to 1.5×10 20 ions/cm 2 ; and the first heavily-doped region and the second heavily-doped region are each of a length of 2 μm to 5 μm.