Semiconductor device

• US 9,923,097 B2
• Filed: 12/03/2014
• Issued: 03/20/2018
• Est. Priority Date: 12/06/2013
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Koezuka, Junichi, Jintyou, Masami, Shima, Yukinori
• Primary Examiner(s): Erdem, Fazli
• Application Number:
  US14/558,857
• Publication Number:
  US 20150162452A1
• Time in Patent Office: 1,203 Days
• CPC Class Codes: H01L 29/045 by their particular orientation of crystalline planes
• CPC Class Codes: H01L 29/42384 for thin film field effect transistors, e.g. characterised by the thickness or the shape of the insulator or the dimensions, the shape or the lay-out of the conductor
• CPC Class Codes: H01L 29/4908 for thin film semiconductor, e.g. gate of TFT
• CPC Class Codes: H01L 29/4966 the conductor material next to the insulator being a composite material, e.g. organic material, TiN, MoSi2 H01L29/4908, H01L29/4983 take precedence
• CPC Class Codes: H01L 29/78603 characterised by the insulating substrate or support H01L29/78657 takes precedence
• CPC Class Codes: H01L 29/78606 with supplementary region or layer in the thin film or in the insulated bulk substrate supporting it for controlling or increasing the safety of the device H01L29/78642, H01L29/78645 take precedence
• CPC Class Codes: H01L 29/78618 characterised by the drain or the source properties, e.g. the doping structure, the composition, the sectional shape or the contact structure silicide contacts, electrodes in general H01L29/458
• 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

Abstract

A semiconductor device includes an oxide semiconductor film, a gate electrode overlapping the oxide semiconductor film with a gate insulating film therebetween, a nitride insulating film in contact with the oxide semiconductor film, and a conductive film in contact with the oxide semiconductor film. The oxide semiconductor film includes a first region in contact with the gate insulating film and a second region in contact with the conductive film. The second region contains an impurity element. The impurity element concentration of the second region is different from that of the first region.

Claims

1. A semiconductor device comprising:

an oxide semiconductor film;

a gate electrode over the oxide semiconductor film;

a gate insulating film between the oxide semiconductor film and the gate electrode; and

a nitride insulating film over and in contact with the oxide semiconductor film,

wherein the oxide semiconductor film comprises a first region and a second region,

wherein the first region is in contact with the gate insulating film,

wherein the second region is in contact with the nitride insulating film,

wherein the second region contains hydrogen and a rare gas element,

wherein a concentration of the rare gas element in the second region is higher than a concentration of the rare gas element in the first region,

wherein the nitride insulating film contains one of silicon nitride and silicon nitride oxide,

wherein an end portion of the gate insulating film extends beyond an end portion of the gate electrode,

wherein the end portion of the gate insulating film is in contact with the nitride insulating film, and

wherein variation in resistivity of the second region at temperatures from 80 K to 290 K is more than −

20% to less than +20%.

2. The semiconductor device according to claim 1,

wherein the gate insulating film overlaps a part of the second region.

3. The semiconductor device according to claim 1,

wherein the nitride insulating film is in contact with a side surface of the gate electrode.

4. The semiconductor device according to claim 1,

wherein each of the first region and the second region contains the rare gas element.

5. The semiconductor device according to claim 1,

wherein the rare gas element is argon.

6. The semiconductor device according to claim 1,

wherein the gate electrode contains elements constituting the oxide semiconductor film.

7. The semiconductor device according to claim 1,

wherein the gate electrode contains an oxide semiconductor.

8. The semiconductor device according to claim 1,

wherein the oxide semiconductor film contains an In—

Ga—

Zn oxide.

9. The semiconductor device according to claim 1,

wherein the oxide semiconductor film comprises a crystal whose c-axis is aligned in a direction substantially perpendicular to a top surface of the oxide semiconductor film, and

wherein the crystal is a non-single-crystal.

10. A semiconductor device comprising:

an oxide semiconductor film;

a gate electrode overlapping the oxide semiconductor film;

a gate insulating film between the oxide semiconductor film and the gate electrode;

a nitride insulating film in contact with the oxide semiconductor film; and

a conductive film in contact with the oxide semiconductor film,

wherein the oxide semiconductor film comprises a first region and a second region,

wherein the first region is in contact with the gate insulating film,

wherein the second region is in contact with the nitride insulating film and the conductive film,

wherein the second region contains hydrogen and a rare gas element,

wherein a concentration of the rare gas element in the second region is higher than a concentration of the rare gas element in the first region,

wherein the gate electrode has a first taper shape,

wherein the gate insulating film has a second taper shape,

wherein an angle of the first taper shape is different from an angle of the second taper shape, and

wherein variation in resistivity of the second region at temperatures from 80 K to 290 K is more than −

20% to less than +20%.

11. The semiconductor device according to claim 10,

wherein the gate insulating film overlaps a part of the second region.

12. The semiconductor device according to claim 10,

wherein the nitride insulating film is in contact with a side surface of the gate electrode.

13. The semiconductor device according to claim 10,

wherein each of the first region and the second region contains the rare gas element.

14. The semiconductor device according to claim 10,

wherein the rare gas element is argon.

15. The semiconductor device according to claim 10,

wherein the nitride insulating film is a silicon nitride film.

16. The semiconductor device according to claim 10,

wherein the gate electrode contains elements constituting the oxide semiconductor film.

17. The semiconductor device according to claim 10,

wherein the gate electrode contains an oxide semiconductor.

18. The semiconductor device according to claim 10,

wherein the oxide semiconductor film contains an In—

Ga—

Zn oxide.

19. The semiconductor device according to claim 10,

wherein the oxide semiconductor film comprises a crystal whose c-axis is aligned in a direction substantially perpendicular to a top surface of the oxide semiconductor film, and

wherein the crystal is a non-single-crystal.

20. A semiconductor device comprising:

an oxide semiconductor film comprising a source region, a drain region and a channel region between the source region and the drain region;

a gate electrode over the oxide semiconductor film;

a gate insulating film between the oxide semiconductor film and the gate electrode; and

an insulating film over the oxide semiconductor film,

wherein one of the source region and the drain region contains hydrogen and a rare gas element,

wherein a hydrogen concentration of the insulating film is higher than or equal to 1×

10²² atoms/cm³,

wherein an end portion of the gate insulating film extends beyond an end portion of the gate electrode,

wherein the end portion of the gate insulating film is in contact with the insulating film, and

wherein variation in resistivity of the one of the source region and the drain region at temperatures from 80 K to 290 K is more than −

20% to less than +20%.

21. The semiconductor device according to claim 20,

wherein the rare gas element is argon.

22. The semiconductor device according to claim 20,

wherein a hydrogen concentration of one of the source region and the drain region is higher than or equal to 5×

10²⁰ atoms/cm³.