Reflection-transmission type liquid crystal display device and method for manufacturing the same

• US 20040141116A1
• Filed: 01/09/2004
• Published: 07/22/2004
• Est. Priority Date: 11/02/2001
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: You, Chun-Gi
• Granted Patent: US 6,980,268 B2
• Time in Patent Office: Days
• US Class Current: 349/113
• CPC Class Codes: G02F 1/133388 with constructional differences between the display region and the peripheral region
• CPC Class Codes: G02F 1/133555 Transflectors
• CPC Class Codes: G02F 1/1345 Conductors connecting electrodes to cell terminals
• CPC Class Codes: G02F 1/13454 Drivers integrated on the active matrix substrate G02F1/136277 takes precedence
• CPC Class Codes: G02F 1/13458 Terminal pads
• CPC Class Codes: G02F 1/136213 Storage capacitors associated with the pixel electrode
• CPC Class Codes: G02F 1/136227 Through-hole connection of the pixel electrode to the active element through an insulation layer
• CPC Class Codes: G02F 1/136236 using a grey or half tone lithographic process
• CPC Class Codes: G02F 1/13685 Top gates
• CPC Class Codes: H01L 27/1248 with a particular composition or shape of the interlayer dielectric specially adapted to the circuit arrangement

Abstract

Disclosed are a liquid crystal display (LCD) device and a method for manufacturing the LCD device. The LCD device has a substrate including a display region and a pad region located in a periphery of the display region, the display region having a transparent electrode, the pad region having a pad electrode. The transparent electrode and the pad electrode are formed from the same layer. A reflective electrode having a transmission window exposing a portion of the transparent electrode is formed on the transparent electrode. The manufacturing process can be simplified because the transparent electrode is directly connected to the reflective electrode. Since the pad electrode is formed of the same layer as the transparent electrode, no metal corrosion occurs to thereby increase the pad reliability during COG bonding.

Claims

1. A liquid crystal display device comprising:

a substrate having a display region on which pixels are formed and a pad region located in a periphery of the display region, the display region having a transparent electrode, the pad region having a pad electrode, the transparent electrode and the pad electrode formed from the same layer; and

a reflective electrode formed on the transparent electrode, the reflective electrode having a transmission window for exposing a portion of the transparent electrode.

2. The liquid crystal display device as claimed in claim 1, further comprising a barrier metal layer pattern interposed between the transparent electrode and the reflective electrode, the barrier metal layer having substantially the same shape as the reflective electrode.

3. The liquid crystal display device as claimed in claim 2, wherein the barrier metal layer is comprised of material having an etching rate substantially the same as an etching rate of the reflective electrode.

4. The liquid crystal display device as claimed in, claim 2, wherein the transparent electrode is comprised of indium tin oxide (ITO), the reflective electrode is comprised of aluminum-neodymium (Al—

Nd), and the barrier metal layer pattern is comprised of molybdenum-tungsten (Mo—

W).

5. The liquid crystal display device as claimed in claim 1, wherein the pixel comprises an amorphous silicon type thin film transistor.

6. The liquid crystal display device as claimed in claim 1, wherein the pixel comprises a polysilicon type thin film transistor.

7. A liquic crystal display device comprising:

a substrate having a display region and a pad region located in a periphery of the display region;

a thin film transistor formed on the substrate of the display region, the thin film transistor including a gate electrode, first and second electrodes and an active pattern;

a passivation layer formed on the thin film transistor and the substrate and having a hole exposing the second electrode;

a transparent electrode formed on the passivation layer of the display region;

a pad electrode formed on the passivation layer of the pad region, the pad electrode being formed from the same layer of the transparent electrode;

a reflective electrode formed on the transparent electrode and having a transmission window exposing a portion of the transparent electrode; and

a barrier metal layer pattern formed between the transparent electrode and the reflective electrode and having the same shape as the reflective electrode.

8. The liquid crystal display device as claimed in claim 7, wherein the transparent electrode is formed on the hole and the passivation layer so as to be connected to the second electrode through the hole.

9. The liquid crystal display device as claimed in claim 7, wherein the transparent electrode is formed only on the passivation layer except for the hole, and the barrier metal layer pattern and the reflective electrode are formed on the hole and the transparent electrode so as to be connected to the second electrode through the hole.

10. The liquid crystal display device as claimed in claim 7, wherein the barrier metal layer pattern and the reflective electrode are formed only on the transparent electrode except for the hole.

11. The liquid crystal display device as claimed in claim 7, wherein the passivation layer is comprised of an inorganic passivation layer and an organic passivation layer stacked on the inorganic passivation layer.

12. The liquid crystal display device as claimed in claim 11, wherein the organic passivation layer is formed only on the display region excluding the pad region.

13. A method for manufacturing a liquid crystal display device, the method comprising the steps of:

forming a transparent conductive layer on a substrate having a display region and a pad region located in a periphery of the display region;

forming a reflective layer on the substrate having the transparent conductive layer;

annealing the reflective layer to prevent the reflective layer from being lifted; and

patterning the reflective layer to form a reflective electrode.

14. The method for manufacturing a liquid crystal display device as claimed in claim 13, wherein the step of annealing the reflective layer is performed at a temperature above about 100°

C. for more than about 30 minutes.

15. The method for manufacturing a liquid crystal display device as claimed in claim 13, wherein an argon (Ar) plasma process is performed to enhance the adhesion between the transparent conductive layer and the underlying layer.

16. The method for manufacturing a liquid crystal display device as claimed in claim 13, further comprising the step of patterning the transparent conductive layer to form a transparent electrode on the display region and a pad electrode on the pad region, before the step of forming the reflective layer.

17. The method for manufacturing a liquid crystal display device as claimed in claim 16, further comprising the steps of annealing the transparent conductive layer for pattern uniformity of the transparent conductive layer, and hard-baking the transparent conductive layer for increasing the adhesion of the transparent conductive layer, before the step of patterning the transparent conductive layer.

18. The method for manufacturing a liquid crystal display device as claimed in claim 13, further comprising the step of patterning the transparent conductive layer to form a transparent electrode on the display region and a pad electrode on the pad region simultaneously, after the step of forming the reflective electrode.

19. The method for manufacturing a liquid crystal display device as claimed in claim 18, wherein the reflective electrode, the transparent electrode, and the pad electrode are formed using one mask.

20. The method for manufacturing a liquid crystal display device as claimed in claim 19, wherein the mask is a half-tone mask or a slit mask.

21. The method for manufacturing a liquid crystal display device as claimed in claim 13, further comprising the step of depositing a barrier metal layer before the step of depositing the reflective layer.

22. The method for manufacturing a liquid crystal display device as claimed in claim 21, wherein the barrier metal layer is simultaneously patterned to form a barrier metal layer pattern when the reflective layer is patterned to form the reflective electrode.

23. The method for manufacturing a liquid crystal display device as claimed in claim 21, wherein the transparent conductive layer, the barrier metal layer, and the reflective layer are formed at a temperature of about 20°

C. to about 150°

C.

24. The method for manufacturing a liquid crystal display device as claimed in claim 21, wherein the barrier metal layer is composed of material having an etching rate similar to an etching rate of the reflective layer.

25. The method for manufacturing a liquid crystal display device as claimed in claim 21, wherein the transparent conductive layer is comprised of indium-tin-oxide (ITO), the barrier metal layer is comprised of molybdenum-tungsten (Mow), and the reflective layer is comprised of aluminum-neodymium (AINd).

26. A method for manufacturing a liquid crystal display device, the method comprising the steps of:

forming a gate electrode on a display region of a substrate, and a gate pad on a pad region of the substrate located in a periphery of the display region;

forming a gate insulation layer to cover the gate electrode and the gate pad;

forming an active pattern and an ohmic contact pattern on the gate insulation layer;

forming a first electrode and a second electrode on the ohmic contact pattern, and simultaneously forming a data pad on the gate insulation layer in the pad region;

forming a passivation layer on the first and second electrodes, the data pad, and the gate insulation layer;

etching the passivation layer to form first, second, and third contact holes for exposing the second electrode, the gate pad, and the data pad, respectively;

forming a transparent electrode on the display region and simultaneously, forming a gate pad electrode and a data pad electrode connected to the gate pad and the data pad through the second and third contact holes, respectively;

successively forming a barrier metal layer and a reflective layer on the transparent electrode and the pad electrodes;

annealing the reflective layer for preventing lifting of the reflective layer; and

patterning the reflective layer and the barrier metal layer to form a reflective layer and a barrier metal layer pattern on the transparent electrode.

27. The method for manufacturing a liquid crystal display device as claimed in claim 26, wherein the active pattern is comprised of amorphous silicon.

28. The method for manufacturing a liquid crystal display device as claimed in claim 26, wherein the active pattern, the ohmic contact pattern, the first electrode, the second electrode, and the data pad are formed using one mask.

29. The method for manufacturing a liquid crystal display device as claimed in claim 26, wherein the passivation layer is comprised of an inorganic passivation layer and an organic passivation layer stacked on the inorganic passivation layer.

30. The method for manufacturing a liquid crystal display device as claimed in claim 29, wherein the organic passivation layer of the pad region is removed in the step of etching the passivation layer to form the first, second, and third contact holes.

31. The method for manufacturing a liquid crystal display device as claimed in claim 26, wherein the transparent electrode is formed on the first contact hole and the passivation layer so as to be connected to the second electrode through the first contact hole.

32. The method for manufacturing a liquid crystal display device as claimed in claim 26, wherein the transparent electrode is formed only on the passivation layer excluding first contact hole, and the barrier metal layer pattern and the reflective electrode are formed on the first contact hole and the transparent electrode so as to be connected to the second electrode through the first contact hole.

33. The method for manufacturing a liquid crystal display device as claimed in claim 26, wherein the barrier metal layer pattern and the reflective electrode are formed only on the transparent electrode excluding the first contact hole.

34. The method for manufacturing a liquid crystal display device as claimed in claim 26, wherein the step of forming the transparent electrode and the gate and data pad electrodes further comprises the steps of:

performing an argon plasma process for enhancing the adhesion between the passivation layer and the transparent electrode;

forming a transparent conductive layer on the first, second, and third contact holes and the passivation layer;

annealing the transparent conductive layer for pattern uniformity of the transparent conductive layer;

hard-baking the transparent conductive layer for increasing the adhesion of the transparent conductive layer; and

patterning the transparent conductive layer.

35. The method for manufacturing a liquid crystal display device as claimed in claim 26, wherein the step of annealing the reflective layer is performed at a temperature above about 100°

C. for more than about 30 minutes.

36. The method for manufacturing a liquid crystal display device as claimed in claim 26, wherein the transparent electrode, the pad electrode, the barrier metal layer pattern, and the reflective electrode are formed using one mask.

37. A method for manufacturing a liquid crystal display device, the method comprising the steps of:

forming an active pattern on a substrate;

forming a gate insulation layer on the substrate having the active pattern;

forming a gate electrode on the gate insulation layer where the active pattern is formed;

successively forming first and second interlayer dielectric layers on the gate electrode and the gate insulation layer;

etching the first and second interlayer dielectric layers and the gate insulating layer to form contact holes respectively exposing first and second regions of the active pattern;

forming first and second electrodes respectively coupled to the first and second regions through the contact holes;

forming a passivation layer on the second interlayer dielectric layer having the first and second electrodes;

etching the passivation layer to form a via hole for exposing the second electrode;

forming a transparent electrode on the passivation layer;

successively forming a barrier metal layer and a reflective layer on the transparent electrode;

annealing the reflective layer for preventing the reflective layer from being lifted; and

patterning the reflective layer and the barrier metal layer to form a barrier metal layer pattern and a reflective electrode.

38. The method for manufacturing a liquid crystal display device as claimed in claim 37, wherein the active pattern is formed of polysilicon.

39. The method for manufacturing a liquid crystal display device as claimed in claim 37, wherein a lower electrode of a capacitor is simultaneously formed on the gate insulation layer besides the active pattern in the step of forming the gate electrode.

40. The method for manufacturing a liquid crystal display device as claimed in claim 37, further comprising the step of etching the second interlayer dielectric layer to expose the first interlayer dielectric layer over the lower electrode of the capacitor before the step of forming the contact holes.

41. The method for manufacturing a liquid crystal display device as claimed in claim 37, further comprising the step of etching the second interlayer dielectric layer to expose the first interlayer dielectric layer over the lower electrode of the capacitor after the step of forming the contact holes.

42. The method for manufacturing a liquid crystal display device as claimed in claim 37, wherein the second electrode is formed to be overlapped with the lower electrode of the capacitor.

43. The method for manufacturing a liquid crystal display device as claimed in claim 37, wherein the first interlayer dielectric layer is comprised of oxide, and the second interlayer dielectric layer is comprised of nitride.

44. The method for manufacturing a liquid crystal display device as claimed in claim 37, wherein the transparent electrode is formed on the via hole and the passivation layer so as to be connected to the second electrode through the via hole.

45. The method for manufacturing a liquid crystal display device as claimed in claim 37, wherein the transparent electrode is formed only on the passivation layer excluding via hole, and the barrier metal layer pattern and the reflective electrode are formed on the via hole and the transparent electrode so as to be connected to the second electrode through the via hole.

46. The method for manufacturing a liquid crystal display device as claimed in claim 37, wherein the barrier metal layer pattern and the reflective electrode are formed only on the transparent electrode excluding the via hole.

47. The method for manufacturing a liquid crystal display device as claimed in claim 37, wherein the step of forming the transparent electrode further comprises the steps of:

performing an argon plasma process for enhancing the adhesion between the passivation layer and the transparent electrode;

forming a transparent conductive layer on the via hole and the passivation layer;

annealing the transparent conductive layer for pattern uniformity of the transparent conductive layer;

hard-baking the transparent conductive layer for increasing the adhesion of the transparent conductive layer; and

patterning the transparent conductive layer.

48. The method for manufacturing a liquid crystal display device as claimed in claim 37, wherein the step of annealing the reflective layer is performed at a temperature above about 100°

C. for more than about 30 minutes.

49. The method for manufacturing a liquid crystal display device as claimed in claim 37, wherein the transparent electrode, the pad electrode, the barrier metal layer pattern, and the reflective electrode are formed using one mask.