Manufacturing methods of thin film transistor, liquid crystal display device, and semiconductor device

• US 8,628,987 B2
• Filed: 08/24/2011
• Issued: 01/14/2014
• Est. Priority Date: 08/27/2010
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei
• Primary Examiner(s): Coleman, William D
• Assistant Examiner(s): ENAD, CHRISTINE A
• Application Number:
  US13/216,501
• Publication Number:
  US 20120052625A1
• Time in Patent Office: 874 Days
• Field of Search: 438/104, 438/30, 257/E21.414
• US Class Current: 438/30
• 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 27/1225 with semiconductor materials not belonging to the group IV of the periodic table, e.g. InGaZnO
• CPC Class Codes: H01L 27/1255 integrated with passive devices, e.g. auxiliary capacitors
• CPC Class Codes: H01L 27/1288 employing particular masking sequences or specially adapted masks, e.g. half-tone mask
• CPC Class Codes: H01L 29/41733 for thin film transistors with insulated gate

Abstract

A liquid crystal display device is provided with high productivity at low cost by reducing manufacturing steps of the liquid crystal display device. A liquid crystal display device with less power consumption and high reliability is provided. Etching of a semiconductor layer and formation of a contact hole that connects a pixel electrode and a drain electrode are performed by one photolithography process and one etching step, whereby the number of photolithography processes is reduced. A liquid crystal display device can be provided with high productivity at low cost by reducing the number of photolithography processes. Further, an oxide semiconductor is used for the semiconductor layer, whereby a liquid crystal display device with less power consumption and high reliability can be provided.

Claims

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

forming a gate electrode over a substrate through a first photolithography process;

forming a gate insulating layer over the gate electrode;

forming a semiconductor layer over the gate insulating layer;

forming a source electrode and a drain electrode over the semiconductor layer through a second photolithography process;

forming an insulating layer over the source electrode and the drain electrode;

through a third photolithography process, forming a contact hole by removing a first part of the insulating layer, and forming an island-like semiconductor layer by removing a second part of the insulating layer, a part of the semiconductor layer, and a part of the gate insulating layer; and

forming a pixel electrode over the insulating layer through a fourth photolithography process,

wherein the source electrode and the drain electrode are in contact with the island-like semiconductor layer,

wherein the first part of the insulating layer overlaps with the drain electrode, and

wherein the second part of the insulating layer, the part of the semiconductor layer and the part of the gate insulating layer do not overlap with the source electrode and the drain electrode.

2. The manufacturing method of the liquid crystal display device, according to claim 1, further comprising the step of forming a base layer over the substrate before forming the gate electrode.

3. The manufacturing method of the liquid crystal display device, according to claim 1, wherein the semiconductor layer comprises an oxide semiconductor.

4. The manufacturing method of the liquid crystal display device according to claim 1, wherein at least one of the gate electrode, the source electrode, and the drain electrode comprises a material comprising copper.

5. The manufacturing method of the liquid crystal display device, according to claim 4, wherein a maximum process temperature at the time after the formation of at least the one of the gate electrode, the source electrode, or the drain electrode is 450°

C. or lower.

6. The manufacturing method of the liquid crystal display device, according to claim 1, wherein at least one of the gate electrode, the source electrode, and the drain electrode comprises a material comprising aluminum.

7. The manufacturing method of the liquid crystal display device, according to claim 6, wherein a maximum process temperature at the time after the formation of at least the one of the gate electrode, the source electrode, and the drain electrode is 380°

C. or lower.

8. The manufacturing method of the liquid crystal display device, according to claim 1,

wherein the source electrode has a U-shape, and

wherein the drain electrode is partly surrounded by the U-shaped source electrode.

9. A manufacturing method of a semiconductor device, comprising the steps of:

forming a gate electrode over a substrate;

forming a gate insulating layer over the gate electrode;

forming a semiconductor layer over the gate insulating layer;

forming a source electrode and a drain electrode over the semiconductor layer;

forming an insulating layer over the source electrode and the drain electrode; and

through a photolithography process, forming a contact hole in the insulating layer by removing a first part of the insulating layer, and forming a patterned semiconductor layer by removing a second part of the insulating layer, a part of the semiconductor layer and a part of the gate insulating layer,

wherein the source electrode and the drain electrode are in contact with the patterned semiconductor layer,

wherein the first part of the insulating layer overlaps with the drain electrode, and

wherein the second part of the insulating layer, the part of the semiconductor layer and the part of the gate insulating layer do not overlap with the source electrode and the drain electrode.

10. The manufacturing method of the semiconductor device, according to claim 9, further comprising the step of forming a base layer over the substrate before forming the gate electrode.

11. The manufacturing method of the semiconductor device, according to claim 9, wherein the semiconductor layer comprises an oxide semiconductor.

12. The manufacturing method of the semiconductor device according to claim 9, wherein at least one of the gate electrode, the source electrode, and the drain electrode comprises a material comprising copper.

13. The manufacturing method of the semiconductor device, according to claim 12, wherein a maximum process temperature at the time after the formation of at least the one of the gate electrode, the source electrode, or the drain electrode is 450°

C. or lower.

14. The manufacturing method of the semiconductor device, according to claim 9, wherein at least one of the gate electrode, the source electrode, and the drain electrode comprises a material comprising aluminum.

15. The manufacturing method of the semiconductor device, according to claim 14, wherein a maximum process temperature at the time after the formation of at least the one of the gate electrode, the source electrode, and the drain electrode is 380°

C. or lower.

16. The manufacturing method of the semiconductor device, according to claim 9, wherein the gate electrode is formed through a photolithography process.

17. The manufacturing method of the semiconductor device, according to claim 9, wherein the source electrode and the drain electrode are formed through a photolithography process.

18. The manufacturing method of the semiconductor device, according to claim 9,

wherein the source electrode has a U-shape, and

wherein the drain electrode is partly surrounded by the U-shaped source electrode.

19. The manufacturing method of the semiconductor device, according to claim 9, wherein the semiconductor device is an active matrix liquid crystal display device.

20. The manufacturing method of the semiconductor device, according to claim 9, wherein the semiconductor device is one selected from the group consisting of a memory device, an imaging device, a display device, an electro-optical device, and an electronic device.

21. A manufacturing method of a semiconductor device, comprising the steps of:

forming a gate electrode over a substrate;

forming a gate insulating layer over the gate electrode;

forming a semiconductor layer over the gate insulating layer;

forming a U-shaped source electrode and a drain electrode over the semiconductor layer; and

forming an insulating layer over the U-shaped source electrode and the drain electrode;

forming a contact hole in the insulating layer by removing a first part of the insulating layer, and forming a patterned semiconductor layer by removing a second part of the insulating layer, a part of the semiconductor layer and a part of the gate insulating layer,

wherein the U-shaped source electrode and the drain electrode are in contact with the patterned semiconductor layer,

wherein the first part of the insulating layer overlaps with the drain electrode, and

wherein the second part of the insulating layer, the part of the semiconductor layer and the part of the gate insulating layer are located outside the U-shaped source electrode.

22. The manufacturing method of the semiconductor device, according to claim 21, further comprising the step of forming a base layer over the substrate before forming the gate electrode.

23. The manufacturing method of the semiconductor device, according to claim 21, wherein the semiconductor layer comprises an oxide semiconductor.

24. The manufacturing method of the semiconductor device according to claim 21, wherein at least one of the gate electrode, the U-shaped source electrode, and the drain electrode comprises a material comprising copper.

25. The manufacturing method of the semiconductor device, according to claim 24, wherein a maximum process temperature at the time after the formation of at least the one of the gate electrode, the U-shaped source electrode, or the drain electrode is 450°

C. or lower.

26. The manufacturing method of the semiconductor device, according to claim 21, wherein at least one of the gate electrode, the U-shaped source electrode, and the drain electrode comprises a material comprising aluminum.

27. The manufacturing method of the semiconductor device, according to claim 26, wherein a maximum process temperature at the time after the formation of at least the one of the gate electrode, the U-shaped source electrode, and the drain electrode is 380°

C. or lower.

28. The manufacturing method of the semiconductor device, according to claim 21, wherein the gate electrode is formed through a photolithography process.

29. The manufacturing method of the semiconductor device, according to claim 21, wherein the U-shaped source electrode and the drain electrode are formed through a photolithography process.

30. The manufacturing method of the semiconductor device, according to claim 21, wherein the semiconductor device is an active matrix liquid crystal display device.

31. The manufacturing method of the semiconductor device, according to claim 21, wherein the semiconductor device is one selected from the group consisting of a memory device, an imaging device, a display device, an electro-optical device, and an electronic device.