Semiconductor device and method for manufacturing the same

• US 9,331,156 B2
• Filed: 12/11/2012
• Issued: 05/03/2016
• Est. Priority Date: 12/15/2011
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei, Akimoto, Kengo, Nonaka, Yusuke, Kanemura, Hiroshi
• Primary Examiner(s): Vu, David
• Assistant Examiner(s): NGUYEN, CUONG B
• Application Number:
  US13/710,867
• Publication Number:
  US 20130153889A1
• Time in Patent Office: 1,239 Days
• US Class Current: 1/1
• CPC Class Codes: H01L 21/02422 Non-crystalline insulating materials, e.g. glass, polymers
• CPC Class Codes: H01L 21/02554 Oxides
• CPC Class Codes: H01L 21/02565 Oxide semiconducting materials not being Group 12/16 materials, e.g. ternary compounds
• CPC Class Codes: H01L 21/02631 Physical deposition at reduced pressure, e.g. MBE, sputtering, evaporation
• CPC Class Codes: H01L 27/1225 with semiconductor materials not belonging to the group IV of the periodic table, e.g. InGaZnO
• CPC Class Codes: H01L 29/04 characterised by their crystalline structure, e.g. polycrystalline, cubic or particular orientation of crystalline planes characterised by physical imperfections H01L29/30
• CPC Class Codes: H01L 29/045 by their particular orientation of crystalline planes
• 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 29/247 Amorphous materials
• CPC Class Codes: H01L 29/41733 for thin film transistors with insulated gate
• 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 29/78696 characterised by the structure of the channel, e.g. multichannel, transverse or longitudinal shape, length or width, doping structure, or the overlap or alignment between the channel and the gate, the source or the drain, or the contacting structure of the channel H01L29/78612 takes precedence; transistors having a drain offset region or a lightly doped drain [LDD] H01L29/78621

Abstract

To manufacture a highly reliable semiconductor device by giving stable electric characteristics to a transistor. An oxide semiconductor film is deposited by a sputtering method with the use of a polycrystalline sputtering target. In that case, partial pressure of water in a deposition chamber before or in the deposition is set to be lower than or equal to 10⁻³ Pa, preferably lower than or equal to 10⁻⁴ Pa, more preferably lower than or equal to 10⁻⁵ Pa. Thus, a dense oxide semiconductor film is obtained. The density of the oxide semiconductor film is higher than 6.0 g/cm³ and lower than 6.375 g/cm³.

Claims

1. A semiconductor device comprising:

a gate electrode layer;

a gate insulating layer over the gate electrode layer;

a non-single-crystal oxide semiconductor film as a channel formation region over the gate insulating layer; and

an insulating layer over the channel formation region,

wherein the non-single-crystal oxide semiconductor film comprises a crystal part,

wherein a concentration of chlorine in the non-single-crystal oxide semiconductor film is lower than or equal to 2×

10¹⁸ atoms/cm³, and

wherein the non-single-crystal oxide semiconductor film has a density of higher than 6.0 g/cm³.

2. The semiconductor device according to claim 1,

wherein the density is measured by X-ray reflectivity or Rutherford backscattering spectrometry.

3. The semiconductor device according to claim 1,

wherein, in the crystal part, a c-axis is aligned in a direction parallel to a normal vector of a surface where the non-single-crystal oxide semiconductor film is formed or a normal vector of a surface of the non-single-crystal oxide semiconductor film.

4. The semiconductor device according to claim 1,

wherein the non-single-crystal oxide semiconductor film comprises at least indium and gallium.

5. The semiconductor device according to claim 1,

wherein the non-single-crystal oxide semiconductor film comprises at least indium, gallium, and zinc.

6. The semiconductor device according to claim 1,

wherein a concentration of copper in the non-single-crystal oxide semiconductor film is lower than or equal to 1×

10¹⁸ atoms/cm³.

7. The semiconductor device according to claim 1,

wherein a concentration of aluminum in the non-single-crystal oxide semiconductor film is lower than or equal to 1×

10¹⁸ atoms/cm³.

8. The semiconductor device according to claim 1,

wherein each of the gate insulating layer and the insulating layer contains excess oxygen,

wherein concentrations of hydrogen in the gate insulating layer and the insulating layer are lower than or equal to 7.2×

10²⁰ atoms/cm³, and

wherein a concentration of hydrogen in the non-single-crystal oxide semiconductor film is lower than or equal to 5×

10¹⁹ atoms/cm³.

9. A semiconductor device comprising:

a gate insulating layer over first and second gate electrode layers; and

a non-single-crystal oxide semiconductor film over the first and second gate electrode layers with the gate insulating layer interposed therebetween,

wherein the non-single-crystal oxide semiconductor film comprises a crystal part,

wherein a concentration of chlorine in the non-single-crystal oxide semiconductor film is lower than or equal to 2×

10¹⁸ atoms/cm³, and

wherein the non-single-crystal oxide semiconductor film has a density of higher than 6.0 g/cm³.

10. The semiconductor device according to claim 9,

wherein the density is measured by X-ray reflectivity or Rutherford backscattering spectrometry.

11. The semiconductor device according to claim 9,

wherein, in the crystal part, a c-axis is aligned in a direction parallel to a normal vector of a surface where the non-single-crystal oxide semiconductor film is formed or a normal vector of a surface of the non-single-crystal oxide semiconductor film.

12. The semiconductor device according to claim 9,

wherein the non-single-crystal oxide semiconductor film comprises at least indium and gallium.

13. The semiconductor device according to claim 9,

wherein the non-single-crystal oxide semiconductor film comprises at least indium, gallium, and zinc.

14. The semiconductor device according to claim 9,

wherein a concentration of copper in the non-single-crystal oxide semiconductor film is lower than or equal to 1×

10¹⁸ atoms/cm³.

15. The semiconductor device according to claim 9,

wherein a concentration of aluminum in the non-single-crystal oxide semiconductor film is lower than or equal to 1×

10¹⁸ atoms/cm³.

16. The semiconductor device according to claim 9,

wherein the gate insulating layer contains excess oxygen,

wherein a concentration of hydrogen in the gate insulating layer is lower than or equal to 7.2×

10²⁰ atoms/cm³, and

wherein a concentration of hydrogen in the non-single-crystal oxide semiconductor film is lower than or equal to 5×

10¹⁹ atoms/cm³.

17. A semiconductor device comprising:

a first gate electrode layer;

a second gate electrode layer over the first gate electrode layer;

a gate insulating layer over the second gate electrode layer;

a non-single-crystal oxide semiconductor film as a channel formation region over the gate insulating layer; and

an insulating layer over the channel formation region,

wherein the non-single-crystal oxide semiconductor film comprises at least indium, gallium, and zinc,

wherein the non-single-crystal oxide semiconductor film comprises a crystal part,

wherein a concentration of chlorine in the non-single-crystal oxide semiconductor film is lower than or equal to 2×

10¹⁸ atoms/cm³, and

wherein the non-single-crystal oxide semiconductor film has a density of higher than 6.0 g/cm³.

18. The semiconductor device according to claim 17,

wherein the density is measured by X-ray reflectivity or Rutherford backscattering spectrometry.

19. The semiconductor device according to claim 17,

wherein, in the crystal part, a c-axis is aligned in a direction parallel to a normal vector of a surface where the non-single-crystal oxide semiconductor film is formed or a normal vector of a surface of the non-single-crystal oxide semiconductor film.

20. The semiconductor device according to claim 17,

wherein each of the gate insulating layer and the insulating layer contains excess oxygen,

wherein concentrations of hydrogen in the gate insulating layer and the insulating layer are lower than or equal to 7.2×

10²⁰ atoms/cm³, and

wherein a concentration of hydrogen in the non-single-crystal oxide semiconductor film is lower than or equal to 5×

10¹⁹ atoms/cm³.