Semiconductor device and method for manufacturing the same

• US 9,287,411 B2
• Filed: 10/23/2013
• Issued: 03/15/2016
• 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): Kim, Su C
• Application Number:
  US14/061,510
• Publication Number:
  US 20140110707A1
• Time in Patent Office: 874 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 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 21/0262 Reduction or decomposition of gaseous compounds, e.g. CVD
• 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 29/513 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 29/78648 arranged on opposing sides of the channel
• 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
• 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

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 oxide semiconductor film has an amorphous structure or a microcrystalline structure, 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 transistor 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 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 over the oxide semiconductor film,

wherein the oxide semiconductor film has an amorphous structure or a microcrystalline structure,

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

wherein each of the oxide semiconductor film and the oxide film includes 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 is a conduction band bottom of the oxide semiconductor film.

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 a concentration of silicon in the oxide semiconductor film is lower than 2×

10¹⁸ atoms/cm³, and

wherein a concentration of silicon at an interface between the oxide semiconductor film and the oxide film is lower than 2×

10¹⁸ atoms/cm³.

6. A display module comprising the semiconductor device according to claim 1.

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

8. A semiconductor device comprising a transistor, the transistor 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 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 over the oxide semiconductor film,

wherein the oxide semiconductor film has an amorphous structure or a microcrystalline structure,

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 the stoichiometric composition,

wherein each of the oxide semiconductor film and the oxide film contains 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 is a conduction band bottom of the oxide semiconductor film.

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 a concentration of silicon in the oxide semiconductor film is lower than 2×

10¹⁸ atoms/cm³, and

wherein a concentration of silicon in a vicinity of an interface between the oxide semiconductor film and the oxide film is lower than 2×

10¹⁸ atoms/cm³.

13. A display module comprising the semiconductor device according to claim 8.

14. An electronic device comprising the semiconductor device according to claim 8.

15. The semiconductor device according to claim 8, wherein an amount of a change of a threshold voltage in a negative direction or a positive direction by a bias-temperature stress test is less than or equal to 1.0 V.

16. A method for manufacturing a semiconductor device, comprising the steps of:

forming a gate electrode over a substrate;

forming a gate insulating film over the gate electrode;

forming a multilayer film including an oxide semiconductor film having an amorphous structure or a microcrystalline structure and an oxide film containing at least one of In and Ga, over the gate insulating film;

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

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

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

wherein the step of forming the first oxide insulating film comprises the steps of;

placing the substrate in a treatment chamber which is vacuum-evacuated and held at temperatures higher than or equal to 180 °

C. and lower than or equal to 400 °

C.; and

setting a pressure in the treatment chamber to be greater than or equal to 20 Pa and less than or equal to 250 Pa with introduction of a first source gas into the treatment chamber, and

wherein the step of forming the second oxide insulating film comprises the steps of;

placing the substrate in a treatment chamber which is vacuum-evacuated and held at temperatures higher than or equal to 180 °

C. and lower than or equal to 260 °

C.;

setting a pressure in the treatment chamber to be greater than or equal to 100 Pa and less than or equal to 250 Pa with introduction of a second source gas into the treatment chamber; and

supplying a frequency power higher than or equal to 0.17 W/cm² and lower than or equal to 0.5 W/cm² to an electrode provided in the treatment chamber.

17. The method for manufacturing a semiconductor device according to claim 16,

wherein, as the first oxide insulating film, a silicon oxide film or a silicon oxynitride film is formed using a deposition gas containing silicon and an oxidizing gas as the first source gas, and

wherein, as the second oxide insulating film, a silicon oxide film or a silicon oxynitride film is formed using the deposition gas containing silicon and the oxidizing gas as the second source gas.

18. The method for manufacturing a semiconductor device according to claim 16,

wherein, as the first oxide insulating film, a silicon oxynitride film is formed using silane and dinitrogen monoxide as the first source gas, and

wherein, as the second oxide insulating film, a silicon oxynitride film is formed using silane and dinitrogen monoxide as the second source gas.