Semiconductor device

• US 8,809,853 B2
• Filed: 03/01/2012
• Issued: 08/19/2014
• Est. Priority Date: 03/04/2011
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Saito, Toshihiko, Kato, Kiyoshi, Isobe, Atsuo
• Primary Examiner(s): Such, Matthew W
• Assistant Examiner(s): SPALLA, DAVID C
• Application Number:
  US13/409,316
• Publication Number:
  US 20120223306A1
• Time in Patent Office: 901 Days
• Field of Search: 257/43, 257/57, 257/E29.242, 257/E29.255, 326/46, 326/149, 326/189.05, 365/46, 365/149, 365/189.05
• US Class Current: 257/43
• CPC Class Codes: G11C 16/0433 comprising cells containing a single floating gate transistor and one or more separate select transistors
• CPC Class Codes: H01L 21/02565 Oxide semiconducting materials not being Group 12/16 materials, e.g. ternary compounds
• CPC Class Codes: H01L 27/0688 Integrated circuits having a three-dimensional layout
• CPC Class Codes: H01L 27/1203 the substrate comprising an insulating body on a semiconductor body, e.g. SOI three-dimensional layout H01L27/0688
• 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 29/408 with an insulating layer with a particular dielectric or electrostatic property, e.g. with static charges or for controlling trapped charges or moving ions, or with a plate acting on the insulator potential or the insulator charges, e.g. for controlling charges effect or potential distribution in the insulating layer, or with a semi-insulating layer contacting directly the semiconductor surface
• CPC Class Codes: H01L 29/4236 within a trench, e.g. trench gate electrode, groove gate electrode
• CPC Class Codes: H01L 29/78 with field effect produced by an insulated gate H01L29/7725, H01L29/775, H01L29/778 take precedence
• 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 29/78696 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
• CPC Class Codes: H10B 41/70 the floating gate being an electrode shared by two or more components

Abstract

With a combination of a transistor including an oxide semiconductor material and a transistor including a semiconductor material other than an oxide semiconductor, a semiconductor device with a novel structure in which data can be retained for a long time and does not have a limitation on the number of writing can be obtained. When a connection electrode for connecting the transistor including a semiconductor material other than an oxide semiconductor to the transistor including an oxide semiconductor material is smaller than an electrode of the transistor including a semiconductor material other than an oxide semiconductor that is connected to the connection electrode, the semiconductor device with a novel structure can be highly integrated and the storage capacity per unit area can be increased.

Claims

1. A semiconductor device comprising:

a substrate containing a semiconductor material;

a first transistor formed using the semiconductor material, the first transistor including a channel formation region, a source region, a drain region, a first gate insulating layer, and a first gate electrode;

an insulating layer formed over the first transistor;

a second transistor formed over the insulating layer, the second transistor including an oxide semiconductor layer, a source electrode, a drain electrode, a second gate insulating layer, and a second gate electrode;

a first connection electrode;

a second connection electrode; and

a third connection electrode formed over the second connection electrode,

wherein one of the source electrode and the drain electrode is electrically connected to the first gate electrode with the first connection electrode interposed therebetween,

wherein the other of the source electrode and the drain electrode is electrically connected to one of the source region and the drain region with the second connection electrode and the third connection electrode interposed therebetween, and

wherein the oxide semiconductor layer overlaps with at least a part of the source region or the drain region.

2. The semiconductor device according to claim 1, wherein a length of the first connection electrode in a channel width direction of the first transistor is shorter than a length of the first gate electrode in the channel width direction of the first transistor.

3. The semiconductor device according to claim 1, wherein a length of the third connection electrode in a channel length direction of the first transistor is shorter than a length of the second connection electrode in the channel length direction of the first transistor.

4. The semiconductor device according to claim 1, wherein a part of the oxide semiconductor layer overlaps with the second connection electrode.

5. The semiconductor device according to claim 1, wherein the length of the third connection electrode in the channel width direction of the first transistor is substantially equal to the length of the first connection electrode in the channel width direction of the first transistor.

6. The semiconductor device according to claim 1,

wherein the insulating layer is a stack of a first insulating layer and a second insulating layer,

wherein the first insulating layer is formed on the same layer as the first gate electrode and the second connection electrode,

wherein the second insulating layer is formed on the same layer as the first connection electrode and the third connection electrode, and

wherein a proportion of oxygen in the second insulating layer is higher than a proportion of oxygen in the first insulating layer.

7. The semiconductor device according to claim 1, wherein a capacitor is constituted by one of the source electrode and the drain electrode, the second gate insulating layer, and a conductive layer.

8. The semiconductor device according to claim 1, wherein the semiconductor material includes silicon.

9. The semiconductor device according to claim 1, wherein the oxide semiconductor layer includes an oxide semiconductor material containing In, Ga, and Zn.

10. A semiconductor device comprising the plurality of semiconductor devices according to claim 1, wherein the plurality of semiconductor devices is electrically connected to a wiring provided over the second transistor in parallel.

11. A semiconductor device comprising:

a substrate containing a semiconductor material;

a first transistor formed using the semiconductor material, the first transistor including a channel formation region, a source region, a drain region, a first gate insulating layer, and a first gate electrode;

an insulating layer formed over the first transistor;

a second transistor formed over the insulating layer, the second transistor including an oxide semiconductor layer, a source electrode, a drain electrode, a second gate insulating layer, and a second gate electrode;

a first connection electrode;

a second connection electrode; and

a third connection electrode formed over the second connection electrode,

wherein the first connection electrode is provided between the first gate electrode and one of the source electrode and the drain electrode,

wherein the second connection electrode and the third connection electrode are provided between one of the source region and the drain region and the other of the source electrode and the drain electrode,

wherein one of the source electrode and the drain electrode is electrically connected to the first gate electrode with the oxide semiconductor layer interposed therebetween,

wherein the other of the source electrode and the drain electrode is electrically connected to one of the source region and the drain region with the oxide semiconductor layer interposed therebetween, and

wherein the oxide semiconductor layer overlaps with at least a part of the source region or the drain region.

12. The semiconductor device according to claim 11, wherein a length of the first connection electrode in a channel length direction of the first transistor is shorter than a length of the first gate electrode in the channel length direction of the first transistor.

13. The semiconductor device according to claim 11, wherein a length of the third connection electrode in a channel width direction of the first transistor is shorter than a length of the second connection electrode in the channel width direction of the first transistor.

14. The semiconductor device according to claim 11, wherein a part of the oxide semiconductor layer overlaps with the second connection electrode.

15. The semiconductor device according to claim 11, wherein the length of the third connection electrode in the channel width direction of the first transistor is substantially equal to the length of the first connection electrode in the channel width direction of the first transistor.

16. The semiconductor device according to claim 11,

wherein the insulating layer is a stack of a first insulating layer and a second insulating layer,

wherein the first insulating layer is formed on the same layer as the first gate electrode and the second connection electrode,

wherein the second insulating layer is formed on the same layer as the first connection electrode and the third connection electrode, and

wherein a proportion of oxygen in the second insulating layer is higher than a proportion of oxygen in the first insulating layer.

17. The semiconductor device according to claim 11, wherein a capacitor is constituted by one of the second source electrode and the second drain electrode, the second gate insulating layer, and a conductive layer.

18. The semiconductor device according to claim 11, wherein the semiconductor material includes silicon.

19. The semiconductor device according to claim 11, wherein the oxide semiconductor layer includes an oxide semiconductor material containing In, Ga, and Zn.

20. The semiconductor device according to claim 11,

wherein a trench is provided over the insulating layer,

wherein the oxide semiconductor layer is provided in contact with a bottom surface and an inner wall surface of the trench.

21. A semiconductor device comprising the plurality of semiconductor devices according to claim 11, wherein the plurality of semiconductor devices is electrically connected to a wiring provided over the second transistor in parallel.