Semiconductor device and method for manufacturing the same

• US 9,349,869 B2
• Filed: 10/23/2013
• Issued: 05/24/2016
• Est. Priority Date: 10/24/2012
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Koezuka, Junichi, Shima, Yukinori, Tokunaga, Hajime, Sasaki, Toshinari, Murayama, Keisuke, Matsubayashi, Daisuke
• Primary Examiner(s): Mandala, Victor A
• Assistant Examiner(s): Jefferson, Quovaunda V
• Application Number:
  US14/060,925
• Publication Number:
  US 20140110705A1
• Time in Patent Office: 944 Days
• US Class Current: 1/1
• CPC Class Codes: H01L 21/022 the layer being a laminate, i.e. composed of sublayers, e.g. stacks of alternating high-k metal oxides adhesion layers or buffer layers H01L21/02304, H01L21/02362
• CPC Class Codes: H01L 21/02263 deposition from the gas or vapour phase
• 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 29/513 the variation being perpendicular to the channel plane
• 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 29/78609 for preventing leakage current H01L29/78618 takes 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

To reduce defects in an oxide semiconductor film in a semiconductor device. To improve the electrical characteristics and the reliability of a semiconductor device including an oxide semiconductor film. In a semiconductor device including a transistor including a gate electrode formed over a substrate, a gate insulating film covering the gate electrode, a multilayer film overlapping with the gate electrode with the gate insulating film provided therebetween, and a pair of electrodes in contact with the multilayer film, a first oxide insulating film covering the transistor, and a second oxide insulating film formed over the first oxide insulating film, the multilayer film includes an oxide semiconductor film and an oxide film containing In or Ga, the first oxide insulating film is an oxide insulating film through which oxygen is permeated, and the second oxide insulating film is an oxide insulating film containing more oxygen than that in the stoichiometric composition.

Claims

1. A semiconductor device comprising a transistor, the semiconductor device comprising:

a gate electrode over a substrate;

a gate insulating film over the gate electrode;

a multilayer film over the gate insulating film;

a pair of electrodes in electrical contact with the multilayer film;

a first oxide insulating film over the gate insulating film, the multilayer film, and the pair of electrodes; and

a second oxide insulating film over the first oxide insulating film,

wherein the multilayer film includes an oxide semiconductor film and an oxide film,

wherein the first oxide insulating film is an oxide insulating film through which oxygen is permeated,

wherein the second oxide insulating film is an oxide insulating film containing more oxygen than that in a stoichiometric composition,

wherein a threshold voltage of the transistor changes in a negative direction or a positive direction, and an amount of change is less than or equal to 1.0 V,

wherein each of the oxide semiconductor film and the oxide film is In-M-Zn oxide,

wherein the M represents Al, Ti, Ga, Y, Zr, La, Ce, Nd, or Hf, and

wherein a proportion of M atoms in the oxide film is higher than a proportion of M atoms in the oxide semiconductor film.

2. The semiconductor device according to claim 1, wherein the oxide semiconductor film contains at least one of In and Ga.

3. The semiconductor device according to claim 1, wherein a conduction band bottom of the oxide film is closer to a vacuum level than a conduction band bottom of the oxide semiconductor film is.

4. The semiconductor device according to claim 3, wherein an energy difference between the conduction band bottom of the oxide film and the conduction band bottom of the oxide semiconductor film is greater than or equal to 0.05 eV and less than or equal to 2 eV.

5. The semiconductor device according to claim 1, wherein an absorption coefficient of the multilayer film derived from a constant photocurrent method is lower than 1×

10<sup>−

3</sup>/cm in an energy range from 1.5 eV to 2.3 eV.

6. The semiconductor device according to claim 1, wherein a concentration of silicon between the oxide semiconductor film and the oxide film is lower than 2×

10¹⁸ atoms/cm³.

7. The semiconductor device according to claim 1, wherein the semiconductor device is one selected from the group consisting of a television device, a computer, and a tablet terminal.

8. A semiconductor device comprising:

a gate electrode over a substrate;

a gate insulating film over the gate electrode;

a multilayer film over the gate insulating film;

a pair of electrodes in electrical contact with the multilayer film;

a first oxide insulating film over the gate insulating film, the multilayer film, and the pair of electrodes; and

a second oxide insulating film over the first oxide insulating film,

wherein the multilayer film includes an oxide semiconductor film and an oxide film,

wherein the second oxide insulating film is an oxide insulating film containing more oxygen than that in a stoichiometric composition,

wherein each of the oxide semiconductor film and the oxide film is In-M-Zn oxide,

wherein the M represents Al, Ti, Ga, Y, Zr, La, Ce, Nd, or Hf, and

wherein a proportion of M atoms in the oxide film is higher than a proportion of M atoms in the oxide semiconductor film.

9. The semiconductor device according to claim 8, wherein the oxide semiconductor film contains at least one of In and Ga.

10. The semiconductor device according to claim 8, wherein a conduction band bottom of the oxide film is closer to a vacuum level than a conduction band bottom of the oxide semiconductor film is.

11. The semiconductor device according to claim 10, wherein an energy difference between the conduction band bottom of the oxide film and the conduction band bottom of the oxide semiconductor film is greater than or equal to 0.05 eV and less than or equal to 2 eV.

12. The semiconductor device according to claim 8, wherein an absorption coefficient of the multilayer film derived from a constant photocurrent method is lower than 1×

10<sup>−

3</sup>/cm in an energy range from 1.5 eV to 2.3 eV.

13. The semiconductor device according to claim 8, wherein a concentration of silicon between the oxide semiconductor film and the oxide film is lower than 2×

10¹⁸ atoms/cm³.

14. The semiconductor device according to claim 8, wherein the semiconductor device is one selected from the group consisting of a television device, a computer, and a tablet terminal.

15. A semiconductor device comprising:

a gate electrode over a substrate;

a gate insulating film over the gate electrode;

a multilayer film over the gate insulating film;

a pair of electrodes in electrical contact with the multilayer film;

a first oxide insulating film over the gate insulating film, and the multilayer film; and

a second oxide insulating film over the first oxide insulating film,

wherein the multilayer film includes an oxide semiconductor film and an oxide film,

wherein the second oxide insulating film is an oxide insulating film containing more oxygen than that in a stoichiometric composition,

wherein each of the oxide semiconductor film and the oxide film is In-M-Zn oxide,

wherein the M represents Al, Ti, Ga, Y, Zr, La, Ce, Nd, or Hf, and

wherein a proportion of M atoms in the oxide film is higher than a proportion of M atoms in the oxide semiconductor film.

16. The semiconductor device according to claim 15, wherein the oxide semiconductor film contains at least one of In and Ga.

17. The semiconductor device according to claim 15, wherein a conduction band bottom of the oxide film is closer to a vacuum level than a conduction band bottom of the oxide semiconductor film is.

18. The semiconductor device according to claim 17, wherein an energy difference between the conduction band bottom of the oxide film and the conduction band bottom of the oxide semiconductor film is greater than or equal to 0.05 eV and less than or equal to 2 eV.

19. The semiconductor device according to claim 15, wherein an absorption coefficient of the multilayer film derived from a constant photocurrent method is lower than 1×

10^-3 /cm in an energy range from 1.5 eV to 2.3 eV.

20. The semiconductor device according to claim 15, wherein a concentration of silicon between the oxide semiconductor film and the oxide film is lower than 2×

10¹⁸ atoms/cm³.

21. The semiconductor device according to claim 15, wherein the semiconductor device is one selected from the group consisting of a television device, a computer, and a tablet terminal.