Semiconductor device

• US 9,443,988 B2
• Filed: 09/30/2014
• Issued: 09/13/2016
• 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:
  US14/501,965
• Publication Number:
  US 20150053975A1
• Time in Patent Office: 714 Days
• Field of Search: 257/40, 257/43, 257/59, 257/79, 257/E29.296, 257/E21.412, 257/E29.273, 257/E21.212, 257/E33.053
• US Class Current: 1/1
• 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 including a first region;

an oxide semiconductor layer over the insulating layer, the oxide semiconductor layer including a second region;

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;

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

the first region is in direct contact with the second region; 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 insulating layer and the gate insulating layer are oxide insulating layers.

3. The semiconductor device according to claim 2,

wherein the oxide insulating layers are silicon oxide, silicon oxynitride, silicon nitride oxide, hafnium oxide, aluminum oxide, or tantalum oxide.

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. The semiconductor device according to claim 1,

wherein the metal is gallium.

9. A semiconductor device comprising:

an insulating layer including a first region;

an oxide semiconductor layer over the insulating layer, the oxide semiconductor layer including a second region;

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;

the oxide semiconductor layer includes a crystal portion;

the first region is in direct contact with the second region; and

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

10²⁰ atoms/cm³.

10. The semiconductor device according to claim 9,

wherein the insulating layer and the gate insulating layer are oxide insulating layers.

11. The semiconductor device according to claim 10,

wherein the oxide insulating layers are silicon oxide, silicon oxynitride, silicon nitride oxide, hafnium oxide, aluminum oxide, or tantalum oxide.

12. The semiconductor device according to claim 9, 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.

13. The semiconductor device according to claim 9,

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

10²⁰ atoms/cm³.

14. The semiconductor device according to claim 9,

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

10¹⁹ atoms/cm³.

15. The semiconductor device according to claim 14,

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

10¹⁹ atoms/cm³.

16. A semiconductor device comprising:

a first insulating layer;

a second insulating layer over the first insulating layer, the second insulating layer including a first region;

an oxide semiconductor layer over the second insulating layer, the oxide semiconductor layer including a second region;

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;

the first insulating layer contains silicon and nitrogen;

the second insulating layer contains silicon and oxygen;

the first region is in direct contact with the second region; and

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

10²⁰ atoms/cm³.

17. The semiconductor device according to claim 16,

wherein the second insulating layer and the gate insulating layer are oxide insulating layers.

18. The semiconductor device according to claim 17,

wherein the oxide insulating layers are silicon oxide, silicon oxynitride, silicon nitride oxide, hafnium oxide, aluminum oxide, or tantalum oxide.

19. The semiconductor device according to claim 16, 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.

20. The semiconductor device according to claim 16,

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

10²⁰ atoms/cm³.

21. The semiconductor device according to claim 16,

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

10¹⁹ atoms/cm³.

22. The semiconductor device according to claim 21,

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

10¹⁹ atoms/cm³.