Semiconductor device and method for manufacturing semiconductor device

• US 9,012,913 B2
• Filed: 01/03/2013
• Issued: 04/21/2015
• Est. Priority Date: 01/10/2012
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Noda, Kosei, Endo, Yuta
• Primary Examiner(s): Loke, Steven
• Assistant Examiner(s): MAZUMDER, DIDARUL A
• Application Number:
  US13/733,536
• Publication Number:
  US 20130175530A1
• Time in Patent Office: 838 Days
• Field of Search: 257/43, 257/57
• US Class Current: 257/57
• CPC Class Codes: H01L 27/1255 integrated with passive devices, e.g. auxiliary capacitors
• CPC Class Codes: H01L 29/04 characterised by their crystalline structure, e.g. polycrystalline, cubic or particular orientation of crystalline planes characterised by physical imperfections H01L29/30
• CPC Class Codes: H01L 29/785 having a channel with a horizontal current flow in a vertical sidewall of a semiconductor body, e.g. FinFET, MuGFET
• 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: H01L 29/78693 the semiconducting oxide being amorphous
• CPC Class Codes: H01L 29/78696 characterised by the structure of the channel, e.g. multichannel, transverse or longitudinal shape, length or width, doping structure, or the overlap or alignment between the channel and the gate, the source or the drain, or the contacting structure of the channel H01L29/78612 takes precedence; transistors having a drain offset region or a lightly doped drain [LDD] H01L29/78621

Abstract

Provided is a fin-type transistor having an oxide semiconductor in a channel formation region in which the channel formation region comprising an oxide semiconductor is three-dimensionally structured and a gate electrode is arranged to extend over the channel formation region. Specifically, the fin-type transistor comprises: an insulator protruding from a substrate plane; an oxide semiconductor film extending beyond the insulator; a gate insulating film over the oxide semiconductor film; and a gate electrode over and extending beyond the oxide semiconductor film. This structure allows the expansion of the width of the channel formation region, which enables the miniaturization and high integration of a semiconductor device having the transistor. Additionally, the extremely small off-state current of the transistor contributes to the formation of a semiconductor device with significantly reduced power consumption.

Claims

1. A semiconductor device comprising:

an insulator over and in contact with a part of an insulating surface;

an oxide semiconductor film over the insulator;

a gate insulating film over and in contact with the oxide semiconductor film and the insulating surface; and

a gate electrode over and in contact with the gate insulating film,

wherein the oxide semiconductor film extends beyond the insulator in a direction perpendicular to a channel length direction so that the oxide semiconductor film is in contact with a top surface of the insulator, a side surface of the insulator, and the insulating surface.

2. The semiconductor device according to claim 1, wherein at least a part of the insulator is entirely wrapped by the insulating surface and the oxide semiconductor film.

3. The semiconductor device according to claim 1, wherein the oxide semiconductor film is entirely wrapped by the insulating surface, the insulator, and the gate insulating film.

4. The semiconductor device according to claim 1, wherein the insulator is entirely wrapped by the oxide semiconductor film and the insulating surface.

5. The semiconductor device according to claim 1, wherein a surface of the insulator, which is in contact with the oxide semiconductor film, comprises a curved surface.

6. The semiconductor device according to claim 1, wherein a surface of the insulator, which is in contact with the oxide semiconductor film, consists of a curved surface.

7. The semiconductor device according to claim 1,

wherein the oxide semiconductor film comprises a channel formation region between a source region and a drain region, and

wherein the source region and the drain region comprise a dopant.

8. An electronic device comprising the semiconductor device according to claim 1.

19. The semiconductor device according to claim 1,

wherein the gate electrode extends beyond the oxide semiconductor film and the insulator in the direction perpendicular to the channel length direction.

20. The semiconductor device according to claim 1,

wherein the oxide semiconductor film comprises a region which is in contact with and interposed between the side surface of the insulator and the gate insulating film.

21. The semiconductor device according to claim 20,

wherein the region extends in a direction perpendicular to the insulating surface.

22. The semiconductor device according to claim 1,

wherein a ratio of a H/W is greater than or equal to 0.5, where H and W are a height and a width of the insulator, respectively, and

wherein the width is a length of the insulator in the direction perpendicular to the channel length direction.

23. The semiconductor device according to claim 1, wherein the insulator is longer than both the gate electrode and the oxide semiconductor film in the channel length direction.

24. The semiconductor device according to claim 1, wherein an entire bottom surface of the insulator is in direct contact with the part of the insulating surface.

9. A semiconductor device comprising:

an insulator over and in contact with a part of an insulating surface;

an oxide semiconductor film over the insulator;

a source electrode and a drain electrode which overlap with a part of the oxide semiconductor film, the source electrode and the drain electrode being in contact with the insulating surface, the insulator, and the part of the oxide semiconductor film;

a gate insulating film over and in contact with the oxide semiconductor film, the insulating surface, the source electrode, and the drain electrode; and

a gate electrode over and in contact with the gate insulating film,

wherein the oxide semiconductor film extends beyond the insulator in a direction perpendicular to a channel length direction so that the oxide semiconductor film is in contact with a top surface of the insulator, a side surface of the insulator, and the insulating surface.

10. The semiconductor device according to claim 9, wherein at least a part of the insulator is entirely wrapped by the insulating surface and the oxide semiconductor film.

11. The semiconductor device according to claim 9, wherein the gate electrode overlaps with the source electrode and the drain electrode.

12. The semiconductor device according to claim 9, wherein the oxide semiconductor film comprises:

a channel formation region which overlaps with the gate electrode;

a pair of low-resistance regions which interposes the channel formation region and comprises a dopant; and

a pair of regions which interposes the pair of low-resistance regions and overlaps with any one of the source electrode and the drain electrode.

13. An electronic device comprising the semiconductor device according to claim 9.

25. The semiconductor device according to claim 9, wherein the insulator is longer than both the gate electrode and the oxide semiconductor film in the channel length direction.

26. The semiconductor device according to claim 9, wherein an entire bottom surface of the insulator is in direct contact with the part of the insulating surface.

14. A semiconductor device comprising:

an insulator over and in contact with a part of an insulating surface;

a source electrode and a drain electrode over and in contact with the insulator and the insulating surface;

an oxide semiconductor film over the source electrode and the drain electrode;

a gate insulating film over and in contact with the insulating surface, the source electrode, the drain electrode, and the oxide semiconductor film; and

a gate electrode over and in contact with the gate insulating film,

wherein the oxide semiconductor film extends beyond the insulator in a direction perpendicular to a channel length direction so that the oxide semiconductor film is in contact with a top surface of the insulator, a side surface of the insulator, and the insulating surface.

15. The semiconductor device according to claim 14, wherein at least a part of the insulator is entirely wrapped by the insulating surface and the oxide semiconductor film.

16. The semiconductor device according to claim 14, wherein the gate electrode overlaps with the source electrode and the drain electrode.

17. The semiconductor device according to claim 14, wherein the oxide semiconductor film comprises:

a channel formation region which overlaps with the gate electrode; and

a pair of low-resistance regions which interposes the channel formation region and comprises a dopant,

wherein a part of the pair of low-resistance regions is in contact with the insulator and another part of the pair of low-resistance regions overlaps with any one of the source electrode and the drain electrode.

18. An electronic device comprising the semiconductor device according to claim 14.

27. The semiconductor device according to claim 14, wherein the insulator is longer than both the gate electrode and the oxide semiconductor film in the channel length direction.

28. The semiconductor device according to claim 14, wherein an entire bottom surface of the insulator is in direct contact with the part of the insulating surface.