Thin Film Transistor and Display Apparatus Having the Same

• US 20130271687A1
• Filed: 03/01/2013
• Published: 10/17/2013
• Est. Priority Date: 04/16/2012
• Status: Active Grant

• Current Assignee: Kookmin University, Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Kookmin University Industry Academy Cooperation Foundation, Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: Ahn, Byung Du, Kim, Dae Hwan, Kim, Jaehyeong, Lim, Jihun, Kim, Gun Hee, Park, Junhyun, Lee, Jehun, Park, Jaewoo, Jung, Hyunkwang
• Granted Patent: US 10,409,126 B2
• Time in Patent Office: Days
• US Class Current: 349/43
• CPC Class Codes: G02F 1/1362 Active matrix addressed cells G02F1/134336, G02F1/134363 take precedence
• 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 29/41725 Source or drain electrodes for field effect devices with monocrystalline semiconductor on source/drain region H01L29/0843
• CPC Class Codes: H01L 29/41733 for thin film transistors with insulated gate
• CPC Class Codes: H01L 29/41783 Raised source or drain electrodes self aligned with the gate
• CPC Class Codes: H01L 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate
• CPC Class Codes: H10K 10/84 Ohmic electrodes, e.g. source or drain electrodes

Abstract

A thin film transistor includes a gate electrode, a first insulating layer disposed to cover the gate electrode, a semiconductor layer disposed on the first insulating layer that includes a first side surface portion, a source electrode disposed on the semiconductor layer, and a drain electrode disposed on the first insulating layer that includes a second side surface portion. The first side surface portion makes contact with the second side surface portion.

Claims

1. A thin film transistor comprising:

a gate electrode;

a first insulating layer covering the gate electrode;

a semiconductor layer disposed on the first insulating layer wherein the semiconductor layer includes a first side surface portion;

a source electrode disposed on the semiconductor layer; and

a drain electrode disposed on the first insulating layer, wherein the drain electrode includes a second side surface portion,

wherein the first side surface portion makes contact with the second side surface portion.

2. The thin film transistor of claim 1, wherein the semiconductor layer is disposed between the source electrode and the first insulating layer, and the drain electrode makes direct contact with an upper surface of the first insulating layer.

3. The thin film transistor of claim 1, wherein an overlap area of the gate electrode with respect to the source electrode is greater than an overlap area of the gate electrode with respect to the drain electrode.

4. The thin film transistor of claim 1, further comprising an etch stopper disposed between the source electrode and the drain electrode to cover an upper surface of the semiconductor layer.

5. The thin film transistor of claim 1, wherein the semiconductor layer comprises an oxide semiconductor that includes at least one of indium (In), gallium (Ga), zinc (Zn), and tin (Sn).

6. The thin film transistor of claim 1, wherein the drain electrode does not substantially overlap the semiconductor layer.

7. The thin film transistor of claim 1, further comprising a base substrate upon which the gate electrode is disposed, wherein a distance between the base substrate and an upper surface of the source electrode is greater than a distance between the base substrate and the second upper surface portion.

8. A display apparatus comprising:

a display device; and

a thin film transistor that applies a driving signal to the display device, wherein the thin film transistor comprises;

a gate electrode;

a first insulating layer that covers the gate electrode;

a semiconductor layer disposed on the first insulating layer that includes a side surface portion;

a source electrode disposed on the semiconductor layer to make contact with the upper surface portion; and

a drain electrode disposed on the first insulating layer spaced apart from the source electrode that contacts the side surface portion of the semiconductor layer.

9. The display apparatus of claim 8, wherein the semiconductor layer is disposed between the source electrode and the first insulating layer and the drain electrode makes direct contact with an upper surface of the first insulating layer.

10. The display apparatus of claim 8, wherein an overlap area of the gate electrode with the source electrode is greater than an overlap area of the gate electrode with the drain electrode.

11. The display apparatus of claim 8, wherein the drain electrode does not substantially overlap the semiconductor layer.

12. The display apparatus of claim 8, further comprising an etch stopper disposed between the source electrode and the drain electrode to cover an upper surface of the semiconductor layer.

13. The display apparatus of claim 8, wherein the display device comprises:

a first electrode connected to the thin film transistor;

a second electrode configured to form an electric field in cooperation with the first electrode; and

a liquid crystal layer operated by the electric field.

14. The display apparatus of claim 13, further comprising a first base substrate upon which the gate electrode is disposed, a second base substrate facing the first base substrate with the liquid crystal layer interposed therebetween, wherein the first electrode is disposed on the first base substrate and the second electrode is disposed on the second base substrate.

15. The display apparatus of claim 13, further comprising a first base substrate upon which the gate electrode is disposed, a second base substrate facing the first base substrate with the liquid crystal layer interposed therebetween, wherein the first electrode and the second electrode are disposed on the first base substrate and insulated from each other.

16. The display apparatus of claim 15, wherein the first electrode is an integrally-formed single body plate, the second electrode comprises a plurality of branches, and the first electrode overlaps the branches.

17. The display apparatus of claim 16, further comprising:

a gate line that extends in a first direction to apply a gate signal to the gate electrode;

a data line that extends in a second direction crossing the first direction to apply a data signal to the source electrode; and

a common voltage line that extends in the first direction spaced apart from the gate line to apply a common voltage to the second electrode.

18. The display apparatus of claim 16, further comprising:

a second insulating layer disposed on the thin film transistor; and

a third insulating layer disposed on the second insulating layer,

wherein the first electrode is disposed on the second insulating layer and the second electrode is disposed on the third insulating layer.

19. A thin film transistor comprising:

a gate electrode;

a first insulating layer covering the gate electrode;

a semiconductor layer disposed on the first insulating layer that overlaps at least a portion of the gate electrode;

a source electrode disposed on the semiconductor layer; and

a drain electrode disposed on the first insulating layer that is spaced apart from the gate electrode,

wherein an overlap area of the gate electrode with respect to the source electrode is greater than an overlap area of the gate electrode with respect to the drain electrode.

20. The thin film transistor of claim 19, wherein semiconductor layer includes a first side surface, the drain electrode includes a second side surface, and the first side surface makes contact with the second side surface.