Semiconductor device and method for manufacturing the same

• US 9,076,871 B2
• Filed: 11/15/2012
• Issued: 07/07/2015
• Est. Priority Date: 11/30/2011
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei, Matsubayashi, Daisuke
• Primary Examiner(s): Ahmad, Khaja
• Application Number:
  US13/677,658
• Publication Number:
  US 20130134413A1
• Time in Patent Office: 964 Days
• Field of Search: 257/43, 257/E29.068, 257/E29.145, 257/E29.273, 257/E29.296, 257/E31.062, 252/519.15, 438/104
• US Class Current: 1/1
• CPC Class Codes: H01L 29/786 Thin film transistors, i.e. transistors with a channel being at least partly a thin film transistors having only the source or the drain region on an insulator layer H01L29/0653; thin film FinFETs H01L29/785
• 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

One embodiment of the present invention is a material which is suitable for a semiconductor included in a transistor, a diode, or the like. One embodiment of the present invention is an oxide material represented as InM1_XM2_(1-X)Zn_YO_Z (0<X<1, 0<Y<1, and Z<1), where M1 is an element belonging to Group 13 and preferably Ga, and M2 is an element belonging to Group 4 or 14. Typically, the content of M2 is arranged to be greater than or equal to 1 atomic % and less than 50 atomic % of that of M1. Generation of oxygen vacancies can be suppressed in an oxide semiconductor material having the above composition. It is also possible to further improve reliability of a transistor with the oxide semiconductor material with the above composition by compensating oxygen vacancies with excessive oxygen.

Claims

1. A semiconductor device comprising:

a gate electrode layer;

a gate insulating layer overlapping with the gate electrode layer; and

an oxide semiconductor layer overlapping with the gate electrode layer with the gate insulating layer positioned therebetween, the oxide semiconductor layer comprising a channel formation region;

wherein the oxide semiconductor layer includes copper having a concentration lower than or equal to 1×

10¹⁷ atoms/cm³,

wherein the oxide semiconductor layer includes aluminum having a concentration lower than or equal to 1×

10¹⁸ atoms/cm³,

wherein the oxide semiconductor layer includes chlorine having a concentration lower than or equal to 2×

10¹⁸ atoms/cm³,

wherein the channel formation region comprises an oxide material represented as InM1_xM2_(1-x)Zn_yO_z(0<

X<

1, 0<

Y<

1, and Z>

1),

wherein M1 is an element belonging to Group 13,

wherein M2 is an element belonging to Group 4 or Group 14, and

wherein a content of M2 is greater than or equal to 1 atomic % and less than 50 atomic % of a content of M1.

2. The semiconductor device according to claim 1, wherein M1 is gallium.

3. The semiconductor device according to claim 1, wherein M2 is any one of titanium, zirconium, hafnium, germanium, and tin.

4. The semiconductor device according to claim 1, wherein M2 is any one of titanium, zirconium, and hafnium.

5. An electronic device comprising the semiconductor device according to claim 1.

6. The electronic device according to claim 5, wherein the electronic device is selected from a television set, a computer, and a tablet terminal.

7. A display device comprising the semiconductor device according to claim 1.

8. The semiconductor device according to claim 1, wherein the gate insulating layer contains excessive oxygen.

9. The semiconductor device according to claim 1, wherein a hydrogen concentration of the gate insulating layer is less than 7.2×

10²⁰ atoms/cm³, and

wherein a hydrogen concentration of the oxide semiconductor layer is less than or equal to 5×

10¹⁸ atoms/cm³.

19. The semiconductor device according to claim 1,

wherein the channel formation region comprises crystalline portions, the crystalline portions comprising at least a first crystalline portion and a second crystalline portion,

wherein each of a c-axis of the crystalline portions is aligned in a direction perpendicular to a surface where the oxide semiconductor layer is formed or a surface of the oxide semiconductor layer,

wherein a direction of an a-axis of the first crystalline portion differs from a direction of an a-axis of the second crystalline portion, and

wherein a direction of a b-axis of the first crystalline portion differs from a direction of a b-axis of the second crystalline portion.

10. A semiconductor device comprising:

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

a gate insulating layer over the oxide semiconductor layer; and

a gate electrode layer overlapping with the oxide semiconductor layer with the gate insulating layer positioned therebetween,

wherein the oxide semiconductor layer includes copper having a concentration lower than or equal to 1×

10¹⁷ atoms/cm³,

wherein the oxide semiconductor layer includes aluminum having a concentration lower than or equal to 1×

10¹⁸ atoms/cm³,

wherein the oxide semiconductor layer includes chlorine having a concentration lower than or equal to 2×

10¹⁸ atoms/cm³,

wherein the channel formation region comprises an oxide material represented as InM1_xM2_(1-x)Zn_yO_z(0<

X<

1, 0<

Y<

1, and Z>

1),

wherein M1 is an element belonging to Group 13,

wherein M2 is an element belonging to Group 4 or Group 14,

wherein a content of M2 is greater than or equal to 1 atomic % and less than 50 atomic % of a content of M1, and

wherein the source region and the drain region comprise the oxide material and an impurity element.

11. The semiconductor device according to claim 10, wherein M1 is gallium.

12. The semiconductor device according to claim 10, wherein M2 is any one of titanium, zirconium, hafnium, germanium, and tin.

13. The semiconductor device according to claim 10, wherein M2 is any one of titanium, zirconium, and hafnium.

14. An electronic device comprising the semiconductor device according to claim 10.

15. The electronic device according to claim 14, wherein the electronic device is selected from a television set, a computer, and a tablet terminal.

16. A display device comprising the semiconductor device according to claim 10.

17. The semiconductor device according to claim 10, wherein the gate insulating layer contains excessive oxygen.

18. The semiconductor device according to claim 10, wherein a hydrogen concentration of the gate insulating layer is less than 7.2×

10²⁰ atoms/cm³, and

wherein a hydrogen concentration of the oxide semiconductor layer is less than or equal to 5×

10¹⁸ atoms/cm³.

20. The semiconductor device according to claim 10,

wherein the channel formation region comprises crystalline portions, the crystalline portions comprising at least a first crystalline portion and a second crystalline portion,

wherein each of a c-axis of the crystalline portions is aligned in a direction perpendicular to a surface where the oxide semiconductor layer is formed or a surface of the oxide semiconductor layer,

wherein a direction of an a-axis of the first crystalline portion differs from a direction of an a-axis of the second crystalline portion, and

wherein a direction of a b-axis of the first crystalline portion differs from a direction of a b-axis of the second crystalline portion.