Semiconductor device and method for manufacturing the same

• US 7,969,012 B2
• Filed: 03/25/2010
• Issued: 06/28/2011
• Est. Priority Date: 03/26/2007
• Status: Expired due to Fees

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Sasagawa, Shinya
• Primary Examiner(s): Richards; N Drew
• Assistant Examiner(s): DIALLO, MAMADOU L
• Application Number:
  US12/731,824
• Publication Number:
  US 20100176461A1
• Time in Patent Office: 460 Days
• Field of Search: 438/98, 438/100, 438584-688, 257210-211, 257/503, 257/508, 257E33062-E33066, 257E31124-E31126, 257/E51.019
• US Class Current: 257/774
• CPC Class Codes: H01L 21/76804 by forming tapered via holes
• CPC Class Codes: H01L 23/485 consisting of layered constructions comprising conductive layers and insulating layers, e.g. planar contacts H01L23/4821, H01L23/4822, H01L23/4824, H01L23/4825 take precedence; materials H01L23/532, bond pads H01L24/02, bump connectors H01L24/10
• CPC Class Codes: H01L 27/124 with a particular composition, shape or layout of the wiring layers specially adapted to the circuit arrangement, e.g. scanning lines in LCD pixel circuits wiring structures per se H01L23/52
• CPC Class Codes: H01L 29/41733 for thin film transistors with insulated gate
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

A method for easily manufacturing a semiconductor device in which variation in thickness or disconnection of a source electrode or a drain electrode is prevented is proposed. A semiconductor device includes a semiconductor layer formed over an insulating substrate; a first insulating layer formed over the semiconductor layer; a gate electrode formed over the first insulating layer; a second insulating layer formed over the gate electrode; an opening which reaches the semiconductor layer and is formed at least in the first insulating layer and the second insulating layer; and a step portion formed at a side surface of the second insulating layer in the opening.

Claims

1. A semiconductor device comprising:

a semiconductor layer formed over a substrate;

a first insulating layer formed over the semiconductor layer;

a gate electrode formed over the first insulating layer;

a second insulating layer formed over the gate electrode;

an opening which reaches the semiconductor layer and is formed at least in the second insulating layer;

a step portion formed at a side surface of the second insulating layer in the opening; and

a conductive layer which is formed over the second insulating layer, covers a side surface of the opening, and is in contact with the semiconductor layer,

wherein the step portion is provided below a top surface of the gate electrode.

2. The semiconductor device according to claim 1 further comprising an insulating sidewall formed at a side surface of the semiconductor layer.

3. The semiconductor device according to claim 1, wherein a thickness of the semiconductor layer is 10 to 30 nm.

4. The semiconductor device according to claim 1, wherein the second insulating layer comprises one selected from the group consisting of silicon oxide, silicon oxynitride, silicon nitride oxide, an organic material, a siloxane material and an oxazole resin.

5. The semiconductor device according to claim 1, wherein the gate electrode comprises one selected from the group consisting of tantalum, tungsten, titanium, molybdenum, aluminum, copper, chromium and niobium.

6. A semiconductor device comprising:

a semiconductor layer formed over a substrate;

a first insulating layer formed over the semiconductor layer;

a gate electrode formed over the first insulating layer;

a second insulating layer formed over the gate electrode;

an opening which reaches the semiconductor layer and is formed at least in the first insulating layer and the second insulating layer;

a step portion formed at a side surface of the second insulating layer in the opening; and

a conductive layer which is formed over the second insulating layer, covers a side surface of the opening, and is in contact with the semiconductor layer,

wherein the step portion is provided below a top surface of the gate electrode.

7. The semiconductor device according to claim 6 further comprising an insulating sidewall formed at a side surface of the semiconductor layer.

8. The semiconductor device according to claim 6, wherein a thickness of the semiconductor layer is 10 to 30 nm.

9. The semiconductor device according to claim 6, wherein the second insulating layer comprises one selected from the group consisting of silicon oxide, silicon oxynitride, silicon nitride oxide, an organic material, a siloxane material and an oxazole resin.

10. The semiconductor device according to claim 6, wherein the gate electrode comprises one selected from the group consisting of tantalum, tungsten, titanium, molybdenum, aluminum, copper, chromium and niobium.

11. A semiconductor device comprising:

a semiconductor layer formed over a substrate;

a first insulating layer formed over the semiconductor layer;

a gate electrode formed over the first insulating layer;

a second insulating layer formed over the gate electrode;

an opening which reaches the semiconductor layer and is formed at least in the second insulating layer;

a step portion formed at a side surface of the second insulating layer in the opening; and

a conductive layer which is formed over the second insulating layer, covers a side surface of the opening, and is in contact with the semiconductor layer,

wherein a silicide layer is formed on at least a portion exposed by the opening of the semiconductor layer, and

wherein the step portion is provided below a top surface of the gate electrode.

12. The semiconductor device according to claim 11 further comprising an insulating sidewall formed at a side surface of the semiconductor layer.

13. The semiconductor device according to claim 11, wherein a thickness of the semiconductor layer is 10 to 30 nm.

14. The semiconductor device according to claim 11, wherein the second insulating layer comprises one selected from the group consisting of silicon oxide, silicon oxynitride, silicon nitride oxide, an organic material, a siloxane material and an oxazole resin.

15. The semiconductor device according to claim 11, wherein the gate electrode comprises one selected from the group consisting of tantalum, tungsten, titanium, molybdenum, aluminum, copper, chromium and niobium.

16. The semiconductor device according to claim 11, wherein the silicide layer comprises one selected from the group consisting of nickel, titanium, cobalt and platinum.

17. A semiconductor device comprising:

a semiconductor layer formed over a substrate;

a first insulating layer formed over the semiconductor layer;

a gate electrode formed over the first insulating layer;

an insulating sidewall formed at a side surface of the gate electrode;

a second insulating layer formed over the gate electrode;

an opening which reaches the semiconductor layer and is formed at least in the second insulating layer;

a step portion formed at a side surface of the second insulating layer in the opening; and

a conductive layer which is formed over the second insulating layer, covers a side surface of the opening, and is in contact with the semiconductor layer,

wherein the step portion is provided below a top surface of the gate electrode.

18. The semiconductor device according to claim 17 further comprising an insulating sidewall formed at a side surface of the semiconductor layer.

19. The semiconductor device according to claim 17, wherein a thickness of the semiconductor layer is 10 to 30 nm.

20. The semiconductor device according to claim 17, wherein the second insulating layer comprises one selected from the group consisting of silicon oxide, silicon oxynitride, silicon nitride oxide, an organic material, a siloxane material and an oxazole resin.

21. The semiconductor device according to claim 17, wherein the gate electrode comprises one selected from the group consisting of tantalum, tungsten, titanium, molybdenum, aluminum, copper, chromium and niobium.

22. A semiconductor device comprising:

a semiconductor layer formed over a substrate;

a first insulating layer formed over the semiconductor layer;

a gate electrode formed over the first insulating layer;

an insulating sidewall formed at a side surface of the gate electrode;

a second insulating layer formed over the gate electrode;

an opening which reaches the semiconductor layer and is formed at least in the second insulating layer;

a step portion formed at a side surface of the second insulating layer in the opening; and

a conductive layer which is formed over the second insulating layer, covers a side surface of the opening, and is in contact with the semiconductor layer,

wherein a silicide layer is formed on at least a portion exposed by the opening of the semiconductor layer, and

wherein the step portion is provided below a top surface of the gate electrode.

23. The semiconductor device according to claim 22 further comprising an insulating sidewall formed at a side surface of the semiconductor layer.

24. The semiconductor device according to claim 22, wherein a thickness of the semiconductor layer is 10 to 30 nm.

25. The semiconductor device according to claim 22, wherein the second insulating layer comprises one selected from the group consisting of silicon oxide, silicon oxynitride, silicon nitride oxide, an organic material, a siloxane material and an oxazole resin.

26. The semiconductor device according to claim 22, wherein the gate electrode comprises one selected from the group consisting of tantalum, tungsten, titanium, molybdenum, aluminum, copper, chromium and niobium.

27. The semiconductor device according to claim 22, wherein the silicide layer comprises one selected from the group consisting of nickel, titanium, cobalt and platinum.