SEMICONDUCTOR DEVICE

• US 20120001179A1
• Filed: 06/22/2011
• Published: 01/05/2012
• Est. Priority Date: 07/02/2010
• Status: Abandoned Application

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: YAMAZAKI, Shunpei, TAKAHASHI, Masahiro, HIROHASHI, Takuya, TOCHIBAYASHI, Katsuaki, NAKAZAWA, Yasutaka, YOKOYAMA, Masatoshi
• Application Number:
  US13/166,073
• Publication Number:
  US 20120001179A1
• Time in Patent Office: Days
• US Class Current: 257/57
• CPC Class Codes: H01L 29/45 Ohmic electrodes
• CPC Class Codes: H01L 29/4908 for thin film semiconductor, e.g. gate of TFT
• 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 29/78606 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
• CPC Class Codes: H01L 29/78693 the semiconducting oxide being amorphous

Abstract

It is an object to provide a semiconductor device including an oxide semiconductor, which has stable electric characteristics and high reliability. A semiconductor device having a stacked-layer structure of a gate insulating layer; a first gate electrode in contact with one surface of the gate insulating layer; an oxide semiconductor layer in contact with the other surface of the gate insulating layer and overlapping with the first gate electrode; and a source electrode, a drain electrode, and an oxide insulating layer which are in contact with the oxide semiconductor layer is provided, in which the nitrogen concentration of the oxide semiconductor layer is 2×10¹⁹ atoms/cm³ or lower and the source electrode and the drain electrode include one or more of tungsten, platinum, and molybdenum.

Claims

1. A semiconductor device comprising:

a gate insulating layer;

a first gate electrode in contact with one surface of the gate insulating layer;

an oxide semiconductor layer in contact with the other surface of the gate insulating layer and overlapping with the first gate electrode; and

a source electrode, a drain electrode, and an oxide insulating layer which are in contact with the oxide semiconductor layer,

wherein a nitrogen concentration of the oxide semiconductor layer is 2×

10¹⁹ atoms/cm³ or lower, and

wherein the source electrode and the drain electrode include at least one of tungsten, platinum, and molybdenum.

2. The semiconductor device according to claim 1, wherein the gate insulating layer includes at least one of gallium oxide, aluminum oxide, gallium aluminum oxide, and aluminum gallium oxide.

3. The semiconductor device according to claim 1, wherein the oxide insulating layer includes at least one of gallium oxide, aluminum oxide, gallium aluminum oxide, and aluminum gallium oxide.

4. The semiconductor device according to claim 1, wherein a thickness of the oxide semiconductor layer is greater than or equal to 3 nm and less than or equal to 30 nm.

5. The semiconductor device according to claim 1, further comprising a second gate electrode overlapping with the oxide semiconductor layer and the first gate electrode with the oxide insulating layer interposed therebetween.

6. The semiconductor device according to claim 1, wherein the oxide insulating layer contains a Group 13 element.

7. The semiconductor device according to claim 1, wherein the oxide insulating layer includes a region containing oxygen with a higher composition proportion than a stoichiometric composition proportion.

8. The semiconductor device according to claim 1, wherein the gate insulating layer includes a region containing oxygen with a higher composition proportion than a stoichiometric composition proportion.

9. The semiconductor device according to claim 1, wherein nitrogen concentrations of the source electrode and the drain electrode are 2×

10¹⁹ atoms/cm³ or lower.

10. The semiconductor device according to claim 1, wherein the oxide insulating layer comprises a metal oxide.

11. A semiconductor device comprising:

a gate insulating layer;

a first gate electrode in contact with one surface of the gate insulating layer;

an oxide semiconductor layer in contact with the other surface of the gate insulating layer and overlapping with the first gate electrode;

a buffer layer and an oxide insulating layer which are in contact with the oxide semiconductor layer; and

a source electrode and a drain electrode which are electrically connected to the oxide semiconductor layer with the buffer layer interposed therebetween,

wherein a nitrogen concentration of the oxide semiconductor layer is 2×

10¹⁹ atoms/cm³ or lower,

wherein a nitrogen concentration of the buffer layer is 2×

10¹⁹ atoms/cm³ or lower, and

wherein the source electrode and the drain electrode include at least one of tungsten, platinum, and molybdenum.

12. The semiconductor device according to claim 11, wherein the gate insulating layer includes at least one of gallium oxide, aluminum oxide, gallium aluminum oxide, and aluminum gallium oxide.

13. The semiconductor device according to claim 11, wherein the oxide insulating layer includes at least one of gallium oxide, aluminum oxide, gallium aluminum oxide, and aluminum gallium oxide.

14. The semiconductor device according to claim 11, wherein a thickness of the oxide semiconductor layer is greater than or equal to 3 nm and less than or equal to 30 nm.

15. The semiconductor device according to claim 11, further comprising a second gate electrode overlapping with the oxide semiconductor layer and the first gate electrode with the oxide insulating layer interposed therebetween.

16. The semiconductor device according to claim 11, wherein the oxide insulating layer contains a Group 13 element.

17. The semiconductor device according to claim 11, wherein the oxide insulating layer includes a region containing oxygen with a higher composition proportion than a stoichiometric composition proportion.

18. The semiconductor device according to claim 11, wherein the gate insulating layer includes a region containing oxygen with a higher composition proportion than a stoichiometric composition proportion.

19. The semiconductor device according to claim 11, wherein nitrogen concentrations of the source electrode and the drain electrode are 2×

10¹⁹ atoms/cm³ or lower.

20. The semiconductor device according to claim 11, wherein the oxide insulating layer comprises a metal oxide.