Semiconductor device

• US 9,842,939 B2
• Filed: 09/08/2016
• Issued: 12/12/2017
• Est. Priority Date: 05/21/2010
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Endo, Yuta, Sasaki, Toshinari, Noda, Kosei, Sato, Mizuho, Ichijo, Mitsuhiro, Endo, Toshiya
• Primary Examiner(s): Gebreyesus, Yosef
• Application Number:
  US15/259,294
• Publication Number:
  US 20160380106A1
• Time in Patent Office: 460 Days
• CPC Class Codes: H01L 29/24 including, apart from doping materials or other impurities, only semiconductor materials not provided for in groups H01L29/16, H01L29/18, H01L29/20, H01L29/22 including organic materials H10K99/00
• CPC Class Codes: H01L 29/4908 for thin film semiconductor, e.g. gate of TFT
• CPC Class Codes: H01L 29/513 the variation being perpendicular to the channel plane
• CPC Class Codes: H01L 29/517 the insulating material comprising a metallic compound, e.g. metal oxide, metal silicate H01L29/518 takes precedence
• CPC Class Codes: H01L 29/518 the insulating material containing nitrogen, e.g. nitride, oxynitride, nitrogen-doped material
• CPC Class Codes: H01L 29/66969 of devices having semiconductor bodies not comprising group 14 or group 13/15 materials comprising selenium or tellurium in uncombined form other than as impurities in semiconductor bodies of other materials, comprising cuprous oxide or cuprous iodide H01L21/02365
• 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 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate

Abstract

In a transistor having a top-gate structure in which a gate electrode layer overlaps with an oxide semiconductor layer which faints a channel region with a gate insulating layer interposed therebetween, when a large amount of hydrogen is contained in the insulating layer, hydrogen is diffused into the oxide semiconductor layer because the insulating layer is in contact with the oxide semiconductor layer; thus, electric characteristics of the transistor are degraded. An object is to provide a semiconductor device having favorable electric characteristics. An insulating layer in which the concentration of hydrogen is less than 6×10²⁰ atoms/cm³ is used for the insulating layer being in contact with oxide semiconductor layer which forms the channel region. Using the insulating layer, diffusion of hydrogen can be prevented and a semiconductor device having favorable electric characteristics can be provided.

Claims

1. A semiconductor device comprising:

an insulating layer;

an oxide semiconductor layer over and in direct contact with the insulating layer;

a source electrode layer electrically connected to the oxide semiconductor layer;

a drain electrode layer electrically connected to the oxide semiconductor layer; and

a gate insulating layer over the oxide semiconductor layer,

wherein;

each of the source electrode layer and the drain electrode layer contains tantalum and nitrogen,

the gate insulating layer contains silicon and oxygen;

the insulating layer is a stacked layer of a first layer and a second layer;

the first layer contains hafnium and oxygen;

the second layer contains silicon, oxygen and nitrogen; and

a concentration of hydrogen in a part of the insulating layer is greater than zero and less than 6×

10²⁰ atoms/cm³.

2. The semiconductor device according to claim 1,

wherein the oxide semiconductor layer contains indium, zinc and a metal other than indium and zinc.

3. The semiconductor device according to claim 2,

wherein the metal is gallium.

4. The semiconductor device according to claim 1, further comprising a gate electrode layer over the gate insulating layer, wherein the gate electrode layer overlaps with the oxide semiconductor layer with the gate insulating layer interposed therebetween, and the gate electrode layer is provided between the source electrode layer and the drain electrode layer.

5. The semiconductor device according to claim 1,

wherein a concentration of hydrogen in a part of the gate insulating layer is less than 6×

10²⁰ atoms/cm³.

6. The semiconductor device according to claim 1,

wherein the concentration of hydrogen in the part of the insulating layer is less than or equal to 5×

10¹⁹ atoms/cm³.

7. The semiconductor device according to claim 6,

wherein a concentration of hydrogen in a part of the gate insulating layer is less than or equal to 5×

10¹⁹ atoms/cm³.

8. A semiconductor device comprising:

an insulating layer;

an oxide semiconductor layer over and in direct contact with the insulating layer;

a source electrode layer electrically connected to the oxide semiconductor layer;

a drain electrode layer electrically connected to the oxide semiconductor layer; and

a gate insulating layer over the oxide semiconductor layer,

wherein;

each of the source electrode layer and the drain electrode layer contains tantalum and nitrogen,

the gate insulating layer contains silicon and oxygen;

the oxide semiconductor layer includes a crystal portion;

the insulating layer is a stacked layer of a first layer and a second layer;

the first layer contains hafnium and oxygen;

the second layer contains silicon, oxygen and nitrogen; and

a concentration of hydrogen in a part of the insulating layer is greater than zero and less than 6×

10²⁰ atoms/cm³.

9. The semiconductor device according to claim 8,

wherein the oxide semiconductor layer contains indium, zinc and a metal other than indium and zinc.

10. The semiconductor device according to claim 9,

wherein the metal is gallium.

11. The semiconductor device according to claim 8, further comprising a gate electrode layer over the gate insulating layer, wherein the gate electrode layer overlaps with the oxide semiconductor layer with the gate insulating layer interposed therebetween, and the gate electrode layer is provided between the source electrode layer and the drain electrode layer.

12. The semiconductor device according to claim 8,

wherein a concentration of hydrogen in a part of the gate insulating layer is less than 6×

10²⁰ atoms/cm³.

13. The semiconductor device according to claim 8,

wherein the concentration of hydrogen in the part of the insulating layer is less than or equal to 5×

10¹⁹ atoms/cm³.

14. The semiconductor device according to claim 13,

wherein a concentration of hydrogen in a part of the gate insulating layer is less than or equal to 5×

10¹⁹ atoms/cm³.

15. A semiconductor device comprising:

an insulating layer;

an oxide semiconductor layer over and in direct contact with the insulating layer;

a source electrode layer electrically connected to the oxide semiconductor layer;

a drain electrode layer electrically connected to the oxide semiconductor layer; and

a gate insulating layer over the oxide semiconductor layer,

wherein;

each of the source electrode layer and the drain electrode layer contains tantalum and nitrogen,

the gate insulating layer contains silicon and oxygen;

the insulating layer is a stacked layer of a first layer and a second layer;

the first layer contains hafnium and oxygen;

the second layer contains silicon, oxygen and nitrogen; and

a concentration of hydrogen in the insulating layer is greater than zero and less than 6×

10²⁰ atoms/cm³.

16. The semiconductor device according to claim 15,

wherein the oxide semiconductor layer contains indium, zinc and a metal other than indium and zinc.

17. The semiconductor device according to claim 16,

wherein the metal is gallium.

18. The semiconductor device according to claim 15, further comprising a gate electrode layer over the gate insulating layer, wherein the gate electrode layer overlaps with the oxide semiconductor layer with the gate insulating layer interposed therebetween, and the gate electrode layer is provided between the source electrode layer and the drain electrode layer.

19. The semiconductor device according to claim 15,

wherein a concentration of hydrogen in a part of the gate insulating layer is less than 6×

10²⁰ atoms/cm³.

20. The semiconductor device according to claim 15,

wherein the concentration of hydrogen in the insulating layer is less than or equal to 5×

10¹⁹ atoms/cm³.

21. The semiconductor device according to claim 20,

wherein a concentration of hydrogen in a part of the gate insulating layer is less than or equal to 5×

10¹⁹ atoms/cm³.