Semiconductor device and method for manufacturing the same

• US 10,153,346 B2
• Filed: 03/24/2016
• Issued: 12/11/2018
• 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): Nguyen, Cuong B
• Application Number:
  US15/079,156
• Publication Number:
  US 20160204271A1
• Time in Patent Office: 992 Days
• 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 non-single-crystal oxide semiconductor film as a channel formation region;

a source electrode and a drain electrode;

a gate insulating layer over the non-single-crystal oxide semiconductor film, the source electrode, and the drain electrode; and

a gate electrode layer over the gate insulating layer,

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

wherein each of the source electrode and the drain electrode consists essentially of any one of molybdenum, titanium, tantalum, tungsten, copper, chromium, neodymium, and scandium,

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

10¹⁸ atoms/cm³,

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

wherein a top surface of the non-single-crystal oxide semiconductor film is coplanar with a top surface of the source electrode and a top surface of the drain electrode.

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 the non-single-crystal oxide semiconductor film comprises a crystal part.

4. The semiconductor device according to claim 3,

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.

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 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.

9. The semiconductor device according to claim 1, further comprising sidewall insulating layers in contact with side surfaces of the gate electrode layer,

wherein the sidewall insulating layers are over and in contact with the gate insulating layer.

10. A semiconductor device comprising:

an oxide semiconductor film comprising;

a first region; and

a pair of second regions, the first region located between the pair of second regions;

a source electrode and a drain electrode;

a gate insulating layer over the oxide semiconductor film, the source electrode, and the drain electrode; and

a gate electrode layer over the gate insulating layer,

wherein the oxide semiconductor film comprises at least indium, gallium, and zinc,

wherein each of the source electrode and the drain electrode consists essentially of any one of molybdenum, titanium, tantalum, tungsten, copper, chromium, neodymium, and scandium,

wherein the first region comprises a non-single-crystal oxide semiconductor film as a channel formation region,

wherein a resistivity of the pair of second regions is lower than a resistivity of the first region,

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

10¹⁸ atoms/cm³,

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

wherein a top surface of the non-single-crystal oxide semiconductor film is coplanar with a top surface of the source electrode and a top surface of the drain electrode.

11. The semiconductor device according to claim 10,

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

12. The semiconductor device according to claim 10,

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

13. The semiconductor device according to claim 12,

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.

14. The semiconductor device according to claim 10,

wherein the oxide semiconductor film comprises at least indium and gallium.

15. The semiconductor device according to claim 10,

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

10¹⁸ atoms/cm³.

16. The semiconductor device according to claim 10,

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

10¹⁸ atoms/cm³.

17. The semiconductor device according to claim 10,

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 oxide semiconductor film is lower than or equal to 5×

10¹⁹ atoms/cm³.

18. The semiconductor device according to claim 10, further comprising sidewall insulating layers in contact with side surfaces of the gate electrode layer,

wherein the sidewall insulating layers are over and in contact with the gate insulating layer.