Liquid crystal display device and method for manufacturing the same in which a light shielding layer is over the gate electrode or a gate electrode is in a trench

• US 5,742,365 A
• Filed: 01/14/1997
• Issued: 04/21/1998
• Est. Priority Date: 01/15/1996
• Status: Expired due to Term

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Seo, Hyun Sik
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): MALINOWSKI, WALTER J
• Application Number:
  US08/783,060
• Time in Patent Office: 462 Days
• Field of Search: 349/42, 349/43, 349/46, 349/110, 257/59, 257/72, 257/301, 257/302, 257/303
• US Class Current: 349/43
• CPC Class Codes: G02F 1/133512 Light shielding layers, e.g. black matrix G02F1/136209 takes precedence
• CPC Class Codes: G02F 1/136209 Light shielding layers, e.g. black matrix, incorporated in the active matrix substrate, e.g. structurally associated with the switching element
• CPC Class Codes: G02F 1/136286 Wiring, e.g. gate line, drain line
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: H01L 27/1214 comprising a plurality of TFTs formed on a non-semiconducting substrate, e.g. driving circuits for AMLCDs
• CPC Class Codes: H01L 27/1262 with a particular formation, treatment or coating of the substrate
• CPC Class Codes: H01L 29/4908 for thin film semiconductor, e.g. gate of TFT
• CPC Class Codes: H01L 29/66765 Lateral single gate single channel transistors with inverted structure, i.e. the channel layer is formed after the gate
• CPC Class Codes: H01L 29/78633 with a light shield

Abstract

A liquid crystal display device includes a substrate, a gate electrode on the substrate, a light shielding layer over the gate electrode and the substrate, an insulating layer over the light shielding layer and the substrate, a semiconductor layer having a channel region on the insulating layer over the gate electrode, source and drain electrodes over first and second portions of the semiconductor layer, respectively, and an ohmic contact layer between the semiconductor layer and each of the source and drain electrodes.

Claims

1. A liquid crystal display device comprising:

a substrate;

a gate electrode on the substrate;

a light shielding layer over the gate electrode and the substrate;

an insulating layer over the light shielding layer and the substrate;

a semiconductor layer having a channel region on the insulating layer over the gate electrode;

source and drain electrodes over first and second portions of the semiconductor layer, respectively; and

an ohmic contact layer between the semiconductor layer and each of the source and drain electrodes.

2. The liquid crystal display device according to claim 1, further comprising:

a passivation layer over the source and drain electrodes, the passivation layer having a contact hole over one of the source and drain electrodes; and

a pixel electrode contacting the one of the source and drain electrodes through the contact hole.

3. The liquid crystal display device according to claim 1, further comprising:

a pixel electrode over the gate insulating layer and contacting one of the source and drain electrodes; and

a passivation layer over the pixel electrode.

4. The liquid crystal display device according to claim 1, further comprising:

a second substrate; and

a second light shielding layer over the second substrate for shielding the channel region.

5. A liquid crystal display device comprising:

a substrate having a trench;

a gate electrode in the trench of the substrate;

a light shielding layer over the gate electrode and the substrate;

an insulating layer over the light shielding layer and the substrate;

a semiconductor layer having a channel region on the insulating layer over the gate electrode;

source and drain electrodes over first and second portions of the semiconductor layer, respectively; and

an ohmic contact layer between the semiconductor layer and each of the source and drain electrodes.

6. The liquid crystal display device according to claim 5, further comprising:

a passivation layer over the source and drain

electrodes, the passivation layer having a contact hole over one of the source and drain electrodes; and

a pixel electrode contacting the one of the source and drain electrodes through the contact hole.

7. The liquid crystal display device according to claim 5, further comprising:

a pixel electrode over the gate insulating layer and contacting one of the source and drain electrodes; and

a passivation layer over the pixel electrode.

8. The liquid crystal display device according to claim 5, further comprising:

a second substrate; and

a second light shielding layer over the second substrate for shielding the channel region.

9. A liquid crystal display device comprising:

a gate electrode on a first substrate;

a black resin layer on at least a first portion of the first substrate and the gate electrode;

a gate insulating film over the black resin layer and on at least a second portion of the first substrate;

a first semiconductor layer on the gate insulating film above the gate electrode;

source and drain electrodes on respective sides of the first semiconductor layer;

a second semiconductor layer between the first semiconductor layer and each of the source and drain electrodes; and

a pixel electrode on a pixel region of the liquid crystal display and connected to one of the source and drain electrodes.

10. The liquid crystal display device according to claim 9, further comprising a second substrate having a second black resin layer, the second black resin layer shielding a channel region between the source electrode and the drain electrode from light.

11. The liquid crystal display device according to claim 9, wherein the first portion of the first substrate has a trench, the black resin layer being located in the trench.

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

forming a gate electrode on a substrate;

forming a light shielding layer comprising a black resin layer, on at least a first portion comprising a black resin layer, of the substrate and on the gate electrode;

forming a gate insulating film over at least a second portion of the substrate and on the black resin layer;

sequentially forming a first semiconductor layer and a second semiconductor layer on the gate insulating film above the gate electrode;

forming source and drain electrodes on respective sides of the first and second semiconductor layers;

depositing a protecting film over at least the source and drain electrodes; and

forming a pixel electrode on a pixel region of the liquid crystal display device and connected to one of the source and drain electrodes.

13. The method of manufacturing a liquid crystal display device according to claim 12, further comprising the step of selectively etching the first portion of the substrate to form a trench where the black resin is located before forming the gate electrode.

14. The method of manufacturing a liquid crystal display device according to claim 12, wherein the black resin layer is formed to a thickness of approximately 0.8˜

1.2 μ

m.

15. The method of manufacturing a liquid crystal display device according to claim 12, wherein the gate insulating film is formed to a thickness of approximately 500˜

1500 Å

.

16. The method of manufacturing a liquid crystal display device according to claim 12, further comprising the step of forming a second substrate having a second light shielding layer, the second light shielding layer being positioned to shield a channel region between the source and drain electrodes.

17. A liquid crystal display device comprising:

a substrate having a trench;

a gate electrode in the trench of the substrate;

an opaque layer on at least a first portion of the substrate and the gate electrode;

a gate insulating film on at least a second portion of the substrate and on the opaque layer;

at least one semiconductor layer above the gate electrode;

source and drain electrodes on respective sides of the semiconductor layer; and

a pixel electrode in electrical contact with one of the source and drain electrodes.

18. The liquid crystal display device according to claim 17, wherein the opaque layer comprises an insulating layer insulating the gate electrode and shielding light.

19. The liquid crystal display device according to claim 18, wherein the insulating layer includes a black resin film.