Semiconductor device and display device including the semiconductor device

Patent metadata

Field	Value
Publication number	US-2016005873-A1
Application number	US-201514755886-A
Country	US
Kind code	A1
Filing date	Jun 30, 2015
Priority date	Jul 3, 2014
Publication date	Jan 7, 2016
Grant date	—

Abstract

A change in electrical characteristics can be suppressed and reliability can be improved in a semiconductor device including a transistor having an oxide semiconductor. A semiconductor device includes a transistor, and the transistor includes an oxide semiconductor film over a first insulating film, a gate insulating film over the oxide semiconductor film, a gate electrode over the gate insulating film, a conductive film in contact with a side surface of the gate electrode in a channel length direction, and a second insulating film over the oxide semiconductor film. The oxide semiconductor film includes a first region overlapping with the gate electrode, a second region overlapping with the conductive film, and a third region in contact with the second insulating film. The third region includes a region having higher impurity element concentration than the second region.

First claim

What is claimed is:

1 . A semiconductor device comprising a transistor, the transistor comprising:
an oxide semiconductor film over a first insulating film; a gate insulating film over the oxide semiconductor film; a gate electrode over the gate insulating film; a conductive film in contact with a side surface of the gate electrode in a channel length direction; and a second insulating film over the oxide semiconductor film, wherein the oxide semiconductor film comprises:
a first region overlapping with the gate electrode;
a second region overlapping with the conductive film; and
a third region in contact with the second insulating film,
wherein the second region and the third region comprise an impurity element, and wherein an impurity element concentration of the third region is higher than an impurity element concentration of the second region.

2 . The semiconductor device according to claim 1 ,
wherein the third region functions as a source region or a drain region of the transistor.

3 . The semiconductor device according to claim 1 ,
wherein the impurity element is one or more of hydrogen, boron, carbon, nitrogen, fluorine, phosphorus, sulfur, and a rare gas.

4 . The semiconductor device according to claim 1 ,
wherein the third region comprises at least one of hydrogen and argon.

5 . The semiconductor device according to claim 1 ,
wherein a hydrogen concentration of the third region is higher than a hydrogen concentration of the second region.

6 . The semiconductor device according to claim 1 ,
wherein the oxide semiconductor film comprises oxygen, indium, zinc, and M, and wherein M is titanium, gallium, tin, yttrium, zirconium, lanthanum, cerium, neodymium, or hafnium.

7 . The semiconductor device according to claim 1 ,
wherein the oxide semiconductor film comprises a crystal part, and wherein a c-axis of the crystal part is parallel to a normal vector to a surface of the oxide semiconductor film.

8 . The semiconductor device according to claim 1 ,
wherein the second insulating film comprises hydrogen.

9 . The semiconductor device according to claim 1 ,
wherein an end portion of the conductive film is substantially aligned with an end portion of the gate insulating film.

10 . The semiconductor device according to claim 1 ,
wherein the second insulating film is in contact with a top surface of the gate electrode, a surface of the conductive film, an end portion of the conductive film, and an end portion of the gate insulating film.

11 . A display device comprising:
the semiconductor device according to claim 10 ; and a display element.

12 . A display module comprising:
the display device according to claim 11 ; and a touch sensor.

13 . A semiconductor device comprising a transistor, the transistor comprising:
a first gate electrode; a first insulating film over the first gate electrode; an oxide semiconductor film over the first insulating film; a gate insulating film over the oxide semiconductor film; a second gate electrode over the gate insulating film; a conductive film in contact with a side surface of the second gate electrode in a channel length direction; and a second insulating film over the oxide semiconductor film, wherein the oxide semiconductor film comprises:
a first region overlapping with the second gate electrode;
a second region overlapping with the conductive film; and
a third region in contact with the second insulating film,
wherein the second region and the third region comprise an impurity element, and wherein an impurity element concentration of the third region is higher than an impurity element concentration of the second region.

14 . The semiconductor device according to claim 13 ,
wherein the third region functions as a source region or a drain region of the transistor.

15 . The semiconductor device according to claim 13 ,
wherein the impurity element is one or more of hydrogen, boron, carbon, nitrogen, fluorine, phosphorus, sulfur, and a rare gas.

16 . The semiconductor device according to claim 13 ,
wherein the third region comprises at least one of hydrogen and argon.

17 . The semiconductor device according to claim 13 ,
wherein a hydrogen concentration of the third region is higher than a hydrogen concentration of the second region.

18 . The semiconductor device according to claim 13 ,
wherein the oxide semiconductor film comprises oxygen, indium, zinc, and M, and wherein M is titanium, gallium, tin, yttrium, zirconium, lanthanum, cerium, neodymium, or hafnium.

19 . The semiconductor device according to claim 13 ,
wherein the second insulating film comprises hydrogen.

20 . The semiconductor device according to claim 13 ,
wherein an end portion of the conductive film is substantially aligned with an end portion of the gate insulating film.

21 . The semiconductor device according to claim 13 ,
wherein the second insulating film is in contact with a top surface of the second gate electrode, a surface of the conductive film, an end portion of the conductive film, and an end portion of the gate insulating film.

Assignees

• Semiconductor Energy Lab

Inventors

• Jintyou Masami
• Iguchi Takahiro

Classifications

• H10D30/6719

  having significant overlap between the lightly-doped drains and the gate electrodes, e.g. gate-overlapped LDD [GOLDD] TFTs · CPC title

• H10D99/00

  Subject matter not provided for in other groups of this subclass · CPC title

• H10D86/423

  comprising semiconductor materials not belonging to the Group IV, e.g. InGaZnO · CPC title

• H10D86/60

  wherein the TFTs are in active matrices · CPC title

• H10D62/405

  Orientations of crystalline planes · CPC title