Semiconductor device including semiconductor electrically surrounded by electric field of conductive film

Patent metadata

Field	Value
Publication number	US-10236287-B2
Application number	US-201414492414-A
Country	US
Kind code	B2
Filing date	Sep 22, 2014
Priority date	Sep 23, 2013
Publication date	Mar 19, 2019
Grant date	Mar 19, 2019

Abstract

A semiconductor device includes a semiconductor, first and second conductive films each including a first region in contact with a top surface of the semiconductor and a second region in contact with a side surface of the semiconductor, a first insulating film including a third region in contact with the semiconductor, a third conductive film including a fourth region facing the semiconductor with the first insulating film therebetween, a second insulating film comprising a fifth region in contact with the first conductive film, and a fourth conductive film comprising a sixth region facing the second region of the first conductive film with the second insulating film therebetween. The semiconductor is electrically surrounded by an electric filed of the third conductive film, therefore, a channel may be formed in the entire semiconductor so that a larger amount of on-state current and reduced off-state current can be obtained.

First claim

What is claimed is:

1. A semiconductor device comprising:
an insulating film having a projection;
a semiconductor over and overlapping with the projection;
a first conductive film and a second conductive film each comprising a first region in contact with a top surface of the semiconductor and a second region in contact with a side surface of the semiconductor;
a first insulating film comprising a third region in contact with the semiconductor;
a third conductive film comprising a fourth region facing the semiconductor with the first insulating film between the semiconductor and the third conductive film;
a second insulating film comprising a fifth region in contact with the second region of the first conductive film; and
a fourth conductive film comprising a sixth region facing the side surface of the semiconductor with the second insulating film and the first conductive film interposed between the sixth region and the side surface of the semiconductor,
wherein the first conductive film comprises a seventh region in direct contact with a side surface of the projection.

2. The semiconductor device according to claim 1 , wherein the semiconductor is a multilayer film comprising a first oxide semiconductor layer and a second oxide semiconductor layer having a higher electron affinity than the first oxide semiconductor layer.

3. The semiconductor device according to claim 1 , wherein the semiconductor is a multilayer film comprising a first oxide semiconductor layer, a second oxide semiconductor layer having a higher electron affinity than the first oxide semiconductor layer over the first oxide semiconductor layer, and a third oxide semiconductor layer having a lower electron affinity than the second oxide semiconductor layer over the second oxide semiconductor layer.

4. The semiconductor device according to claim 1 , wherein the first insulating film and the second insulating film are connected to each other.

5. The semiconductor device according to claim 1 , wherein the semiconductor device further comprises a fifth conductive film overlapping with the first conductive film and electrically connected to the fourth conductive film.

6. The semiconductor device according to claim 1 , wherein the semiconductor device further comprises a third insulating film containing aluminum oxide, aluminum oxynitride, gallium oxide, gallium oxynitride, yttrium oxide, yttrium oxynitride, hafnium oxide, hafnium oxynitride, or yttria-stabilized zirconia, the third insulating film being over the third conductive film and the fourth conductive film.

7. The semiconductor device according to claim 1 , wherein the first insulating film and the second insulating film are not connected to each other.

8. The semiconductor device according to claim 1 , wherein a bottom surface of the semiconductor is located above a bottom surface of each of the first conductive film, second conductive film, and the third conductive film.

9. The semiconductor device according to claim 1 , wherein the fourth conductive film overlaps with the projection.

10. The semiconductor device according to claim 1 , wherein a part of a bottom surface of the third conductive film is below a part of a bottom surface of the first conductive film.

11. The semiconductor device according to claim 1 , further comprising a third insulating film between the first insulating film and the second insulating film.

12. The semiconductor device according to claim 1 , wherein edges of the first insulating film are aligned with edges of the third conductive film, and
wherein edges of the second insulating film are aligned with edges of the fourth conductive film.

13. A semiconductor device comprising:
a first transistor comprising a semiconductor substrate;
a second transistor at least partly overlapping with the first transistor; and
a capacitor at least partly overlapping with the second transistor,
wherein the second transistor comprises:
an insulating film having a projection;
a semiconductor over and overlapping with the projection;
a first conductive film and a second conductive film each comprising a first region in contact with a top surface of the semiconductor and a second region in contact with a side surface of the semiconductor;
a first insulating film comprising a third region in contact with the semiconductor; and
a third conductive film comprising a fourth region facing the semiconductor with the first insulating film between the semiconductor and the third conductive film,

wherein the capacitor comprises:
the first conductive film;
a second insulating film comprising a fifth region in contact with the second region of the first conductive film; and
a fourth conductive film comprising a sixth region facing the side surface of the semiconductor with the second insulating film and the first conductive film interposed between the sixth region and the side surface of the semiconductor, and

wherein the first conductive film comprises a seventh region in direct contact with a side surface of the projection.

14. The semiconductor device according to claim 13 , wherein the semiconductor is a multilayer film comprising a first oxide semiconductor layer and a second oxide semiconductor layer having a higher electron affinity than the first oxide semiconductor layer.

15. The semiconductor device according to claim 13 , wherein the semiconductor is a multilayer film comprising a first oxide semiconductor layer, a second oxide semiconductor layer having a higher electron affinity than the first oxide semiconductor layer over the first oxide semiconductor layer, and a third oxide semiconductor layer having a lower electron affinity than the second oxide semiconductor layer over the second oxide semiconductor layer.

16. The semiconductor device according to claim 13 , wherein the first insulating film and the second insulating film are connected to each other.

17. The semiconductor device according to claim 13 , wherein the semiconductor device further comprises a fifth conductive film overlapping with the first conductive film and electrically connected to the fourth conductive film.

18. The semiconductor device according to claim 13 , wherein the semiconductor device further comprises a third insulating film containing aluminum oxide, aluminum oxynitride, gallium oxide, gallium oxynitride, yttrium oxide, yttrium oxynitride, hafnium oxide, hafnium oxynitride, or yttria-stabilized zirconia, the third insulating film being between the first transistor and the second transistor.

19. The semiconductor device according to claim 13 , wherein the semiconductor device further comprises a third insulating film containing aluminum oxide, aluminum oxynitride, gallium oxide, gallium oxynitride, yttrium oxide, yttrium oxynitride, hafnium oxide, hafnium oxynitride, or yttria-stabilized zirconia, the third insulating film being over the third conductive film and the fourth conductive film.

20. The semiconductor device according to claim 13 , wherein the first insulating film and the second insulating film are not connected to each other.

21. The semiconductor device according to claim 13 , wherein a bottom surface of the semiconductor is located above a bottom surface of each of the first conductive film, second conductive film, and the third conductive film.

22. A semiconductor device comprising:
a first transistor;
a second transistor electrically connected to the first transistor; and
a capacitor,
wherein the second transistor comp

Assignees

• Semiconductor Energy Lab

Inventors

• Yamazaki Shunpei

Classifications

• H01L27/1218

  Electricity · mapped topic

• H01L29/24

  Electricity · mapped topic

• H01L27/1255

  Electricity · mapped topic

• H01L27/1156

  Electricity · mapped topic

• H01L27/0688

  Electricity · mapped topic