Capacitor comprising metal oxide film having high alignment

• US 9,905,586 B2
• Filed: 09/16/2014
• Issued: 02/27/2018
• Est. Priority Date: 09/25/2013
• Status: Expired due to Fees

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei, Koezuka, Junichi, Okazaki, Kenichi, Hosaka, Yasuharu
• Primary Examiner(s): HUBER, ROBERT T
• Application Number:
  US14/487,336
• Publication Number:
  US 20150084045A1
• Time in Patent Office: 1,260 Days
• Field of Search: 257 43, 257306, 257350, 257E27111
• CPC Class Codes: H01L 27/1222 with a particular composition, shape or crystalline structure of the active layer
• 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 27/1255 integrated with passive devices, e.g. auxiliary capacitors

Abstract

An oxide semiconductor film with a low density of defect states is formed. In addition, an oxide semiconductor film with a low impurity concentration is formed. Electrical characteristics of a semiconductor device or the like using an oxide semiconductor film is improved. A semiconductor device including a capacitor, a resistor, or a transistor having a metal oxide film that includes a region; with a transmission electron diffraction measurement apparatus, a diffraction pattern with luminescent spots indicating alignment is observed in 70% or more and less than 100% of the region when an observation area is changed one-dimensionally within a range of 300 nm.

Claims

1. A semiconductor device comprising:

a capacitor comprising a metal oxide film including indium over and in contact with an insulating surface, a conductive film at least partly overlapping with the metal oxide film, and a nitride insulating film in contact with the metal oxide film and between the metal oxide film and the conductive film,

wherein the metal oxide film is a stack of an In-M-Zn oxide film and an In—

N—

Zn oxide film, M and N being each Al, Ti, Ga, Y, Zr, Sn, La, Ce, or Nd,

wherein the In-M-Zn oxide film is on and in direct contact with the In—

N—

Zn oxide film,

wherein the proportion of M atoms in the In-M-Zn oxide film is higher than the proportion of N atoms in the In—

N—

Zn oxide film, and

wherein when a region in the In-M-Zn oxide film is observed with a transmission electron diffraction measurement apparatus while changing an observation area one-dimensionally within a range of 300 nm, a diffraction pattern with luminescent spots indicating alignment is observed in 80% or more and less than 100% of the region.

2. The semiconductor device according to claim 1,

wherein the metal oxide film comprises a plurality of crystal parts,

wherein c-axis alignment is found in the plurality of crystal parts, and

wherein c-axes in the plurality of crystal parts are aligned in a direction parallel to a normal vector of a top surface of the metal oxide film.

3. The semiconductor device according to claim 1,

wherein the metal oxide film comprises a plurality of crystal parts,

wherein a-axes are not aligned in the plurality of crystal parts in the metal oxide film, and

wherein b-axes are not aligned in the plurality of crystal parts in the metal oxide film.

4. The semiconductor device according to claim 1, further comprising a transistor,

wherein the transistor comprises:

a gate electrode over the insulating surface;

an oxide semiconductor film at least partly overlapping with the gate electrode;

a gate insulating film between the gate electrode and the oxide semiconductor film;

a pair of electrodes in contact with the oxide semiconductor film;

an oxide insulating film at least partly overlapping with the pair of electrodes; and

the nitride insulating film in contact with the oxide insulating film.

5. The semiconductor device according to claim 1, wherein the nitride insulating film is formed of silicon nitride, a silicon nitride oxide, an aluminum nitride, or an aluminum nitride oxide.

6. The semiconductor device according to claim 1,

wherein the semiconductor device further comprises a second nitride insulating film over the capacitor, and

wherein the nitride insulating film and the second nitride insulating film are partly in direct contact with each other.

7. A semiconductor device comprising:

a capacitor comprising a nitride insulating film, a metal oxide film including indium in contact with the nitride insulating film, a conductive film at least partly overlapping with the metal oxide film, and an insulating film in contact with the metal oxide film and between the metal oxide film and the conductive film,

wherein the metal oxide film is a stack of an In-M-Zn oxide film and an In—

N—

Zn oxide film, M and N being each Al, Ti, Ga, Y, Zr, Sn, La, Ce, or Nd,

wherein the In-M-Zn oxide film is on and in direct contact with the In—

N—

Zn oxide film,

wherein the proportion of M atoms in the In-M-Zn oxide film is higher than the proportion of N atoms in the In—

N—

Zn oxide film, and

wherein when a region in the In-M-Zn oxide film is observed with a transmission electron diffraction measurement apparatus while changing an observation area one-dimensionally within a range of 300 nm, a diffraction pattern with luminescent spots indicating alignment is observed in 80% or more and less than 100% of the region.

8. The semiconductor device according to claim 7,

wherein the metal oxide film comprises a plurality of crystal parts,

wherein c-axis alignment is found in the plurality of crystal parts, and

wherein c-axes in the plurality of crystal parts are aligned in a direction parallel to a normal vector of a top surface of the metal oxide film.

9. The semiconductor device according to claim 7,

wherein the metal oxide film comprises a plurality of crystal parts,

wherein a-axes are not aligned in the plurality of crystal parts in the metal oxide film, and

wherein b-axes are not aligned in the plurality of crystal parts in the metal oxide film.

10. The semiconductor device according to claim 7, further comprising a transistor,

wherein the transistor comprises:

a gate electrode over an insulating surface;

an oxide semiconductor film at least partly overlapping with the gate electrode;

a gate insulating film between the gate electrode and the oxide semiconductor film;

a pair of electrodes in contact with the oxide semiconductor film; and

an oxide insulating film at least partly overlapping with the pair of electrodes.

11. The semiconductor device according to claim 7, wherein the nitride insulating film is formed of silicon nitride, a silicon nitride oxide, an aluminum nitride, or an aluminum nitride oxide.

12. The semiconductor device according to claim 7,

wherein the semiconductor device further comprises a second nitride insulating film over the capacitor, and

wherein the nitride insulating film and the second nitride insulating film are partly in direct contact with each other.

13. A semiconductor device comprising:

a transistor including a semiconductor substrate; and

a capacitor comprising an insulating film, a metal oxide film including indium in contact with the insulating film, a conductive film at least partly overlapping with the metal oxide film, and a nitride insulating film in contact with the metal oxide film and between the metal oxide film and the conductive film,

wherein the metal oxide film is a stack of an In-M-Zn oxide film and an In—

N—

Zn oxide film, M and N being each Al, Ti, Ga, Y, Zr, Sn, La, Ce, or Nd,

wherein the In-M-Zn oxide film is on and in direct contact with the In—

N—

Zn oxide film,

wherein the proportion of M atoms in the In-M-Zn oxide film is higher than the proportion of N atoms in the In—

N—

Zn oxide film, and

wherein when a region in the In-M-Zn oxide film is observed with a transmission electron diffraction measurement apparatus while changing an observation area one-dimensionally within a range of 300 nm, a diffraction pattern with luminescent spots indicating alignment is observed in 80% or more and less than 100% of the region.

14. The semiconductor device according to claim 13,

wherein the metal oxide film comprises a plurality of crystal parts,

wherein c-axis alignment is found in the plurality of crystal parts, and

wherein c-axes in the plurality of crystal parts are aligned in a direction parallel to a normal vector of a top surface of the metal oxide film.

15. The semiconductor device according to claim 13,

wherein the metal oxide film comprises a plurality of crystal parts,

wherein a-axes are not aligned in the plurality of crystal parts in the metal oxide film, and

wherein b-axes are not aligned in the plurality of crystal parts in the metal oxide film.

16. The semiconductor device according to claim 13, further comprising a second transistor,

wherein the second transistor comprises:

a gate electrode over the transistor;

an oxide semiconductor film at least partly overlapping with the gate electrode;

a gate insulating film between the gate electrode and the oxide semiconductor film;

a pair of electrodes in contact with the oxide semiconductor film;

an oxide insulating film at least partly overlapping with the pair of electrodes; and

the nitride insulating film in contact with the oxide insulating film.

17. The semiconductor device according to claim 13, wherein the nitride insulating film is formed of silicon nitride, a silicon nitride oxide, an aluminum nitride, or an aluminum nitride oxide.

18. The semiconductor device according to claim 13,

wherein the semiconductor device further comprises a second nitride insulating film over the capacitor, and

wherein the nitride insulating film and the second nitride insulating film are partly in direct contact with each other.