Thin film transistor array panel and manufacturing method thereof

1. A thin film transistor array panel, comprising:

a substrate;

a first conductive layer disposed on the substrate and comprising a drain electrode;

a second conductive layer disposed on the first conductive layer and comprising a first portion that overlaps the drain electrode and a second portion that does not overlap the drain electrode;

a first insulating layer disposed on the second conductive layer, the first insulating layer comprising a contact hole exposing at least a portion of a boundary between the first portion and the second portion; and

a third conductive layer disposed on the first insulating layer and contacting the first portion and the second portion through the contact hole.

2. The thin film transistor array panel of claim 1 , wherein the third conductive layer covers the boundary between the first portion and the second portion.

3. The thin film transistor array panel of claim 2 , wherein the first portion of the second conductive layer directly contacts the drain electrode.

4. The thin film transistor array panel of claim 3 , further comprising a common electrode disposed on the first insulating layer and comprising a cutout, wherein,

the second conductive layer comprises a pixel electrode, and

the common electrode and the third conductive layer are formed from the same layer.

5. The thin film transistor array panel of claim 4 , further comprising a common voltage line disposed under the drain electrode,

wherein the common electrode is connected to the common voltage line to receive a common voltage Vcom.

6. The thin film transistor array panel of claim 1 , wherein the first portion of the second conductive layer directly contacts the drain electrode.

7. The thin film transistor array panel of claim 6 , further comprising a common electrode disposed on the first insulating layer and comprising a cutout, wherein,

the second conductive layer comprises a pixel electrode, and

the common electrode and the third conductive layer are formed from the same layer.

8. The thin film transistor array panel of claim 7 , further comprising a common voltage line disposed under the drain electrode, and

wherein the common electrode is connected to the common voltage line to receive a common voltage Vcom.

9. A method for manufacturing a thin film transistor array panel, the method comprising:

forming a first conductive layer on a substrate and comprising a drain electrode;

forming a second conductive layer on the first conductive layer, the second conductive layer comprising a first portion that overlaps the drain electrode and a second portion that does not overlap the drain electrode;

depositing a first insulating layer on the second conductive layer and forming a first contact hole in the first insulating layer, the first contact hole exposing at least a portion of a boundary between the first portion and the second portion; and

forming a third conductive layer on the first insulating layer, the third conductive layer contacting the first portion and the second portion through the first contact hole.

10. The method of claim 9 , wherein the third conductive layer covers the boundary between the first portion and the second portion.

11. The method of claim 10 , wherein the first portion of the second conductive layer directly contacts the drain electrode.

12. The method of claim 11 , further comprising forming a common electrode on the first insulating layer, the common electrode comprising a cutout,

wherein the common electrode and the third conductive layer are simultaneously formed from the same layer.

13. The method of claim 12 , further comprising:

forming a gate line and a common voltage line on the substrate;

forming a second insulating layer on the gate line and the common voltage line; and

forming a second contact hole in the first insulating layer and the second insulating layer, the second contact hole exposing a portion of the common voltage line,

wherein the common electrode is connected to the common voltage line through the second contact hole.

14. The method of claim 9 , wherein the first portion of the second conductive layer directly contacts the drain electrode.

15. The method of claim 14 , further comprising forming a common electrode comprising a cutout on the first insulating layer,

wherein the common electrode and the third conductive layer are simultaneously formed from the same layer.

16. The method of claim 15 , further comprising:

forming a gate line and a common voltage line on the substrate;

forming a second insulating layer on the gate line and the common voltage line; and

forming a second contact hole in the first insulating layer and the second insulating layer, the second contact hole exposing a portion of the common voltage line,

wherein the common electrode is connected to the common voltage line through the second contact hole.

17. A thin film transistor array panel, comprising:

a conductive layer disposed on a substrate, the conductive layer comprising a step difference at a boundary between a first portion of the conductive layer and a second portion of the conductive layer;

an insulating layer disposed on the conductive layer, the insulating layer comprising a contact hole exposing at least a portion of the boundary between the first portion and the second portion; and

an auxiliary conductive layer disposed on the insulating layer as an island, the auxiliary conductive layer contacting the first portion and the second portion through the contact hole and covering the boundary between the first portion and the second portion.

18. The thin film transistor array panel of claim 17 , further comprising

an underlying conductive layer disposed under the first portion but not under the second portion,

wherein the underlying conductive layer contacts the first portion.