Semiconductor device and method for manufacturing the same

Patent metadata

Field	Value
Publication number	US-2016204271-A1
Application number	US-201615079156-A
Country	US
Kind code	A1
Filing date	Mar 24, 2016
Priority date	Dec 15, 2011
Publication date	Jul 14, 2016
Grant date	—

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/cm 3 and lower than 6.375 g/cm 3 .

First claim

1 . (canceled)

2 . A semiconductor device comprising:
a non-single-crystal oxide semiconductor film as a channel formation region; a gate insulating layer over the non-single-crystal oxide semiconductor film; and a gate electrode layer over the gate insulating layer; wherein a concentration of chlorine in the non-single-crystal oxide semiconductor film is lower than or equal to 2×10 18 atoms/cm 3 , and wherein the non-single-crystal oxide semiconductor film has a density of higher than 6.0 g/cm 3 .

3 . The semiconductor device according to claim 2 ,
wherein the density is measured by X-ray reflectivity or Rutherford backscattering spectrometry.

4 . The semiconductor device according to claim 2 ,
wherein the non-single-crystal oxide semiconductor film comprises a crystal part.

5 . The semiconductor device according to claim 4 ,
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.

6 . The semiconductor device according to claims 2 ,
wherein the non-single-crystal oxide semiconductor film comprises at least indium and gallium.

7 . The semiconductor device according to claim 2 ,
wherein the non-single-crystal oxide semiconductor film comprises at least indium, gallium, and zinc.

8 . The semiconductor device according to claim 2 ,
wherein a concentration of copper in the non-single-crystal oxide semiconductor film is lower than or equal to 1×10 18 atoms/cm 3 .

9 . The semiconductor device according to claim 2 ,
wherein a concentration of aluminum in the non-single-crystal oxide semiconductor film is lower than or, equal to 1×10 18 atoms/cm 3 .

10 . The semiconductor device according to claim 2 ,
wherein the gate insulating layer contains excess oxygen, wherein a concentration of hydrogen in the gate insulating layer is lower than or equal to 7.2×10 20 atoms/cm 3 , and wherein a concentration of hydrogen in the non-single-crystal oxide semiconductor film is lower than or equal to 5×10 19 atoms/cm 3 .

11 . The semiconductor device according to claim 2 , 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.

12 . 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 gate insulating layer over the oxide semiconductor film; and a gate electrode layer over the gate insulating layer; 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 2×10 18 atoms/cm 3 , and wherein the non-single-crystal oxide semiconductor film has a density of higher than 6.0 g/cm 3 .

13 . The semiconductor device according to claim 12 ,
wherein the density is measured by X-ray reflectivity or Rutherford backscattering spectrometry.

14 . The semiconductor device according to claim 12 ,
wherein the non-single-crystal oxide semiconductor film comprises a crystal part.

15 . The semiconductor device according to claim 14 ,
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.

16 . The semiconductor device according to claim 12 ,
wherein the oxide semiconductor film comprises at least indium and gallium.

17 . The semiconductor device according to claim 12 ,
wherein the oxide semiconductor film comprises at least indium, gallium, and zinc.

18 . The semiconductor device according to claim 12 ,
wherein a concentration of copper in the oxide semiconductor film is lower than or equal to 1×10 18 atoms/cm 3 .

19 . The semiconductor device according to claim 12 ,
wherein a concentration of aluminum in the oxide semiconductor film is lower than or equal to 1×10 18 atoms/cm 3 .

20 . The semiconductor device according to claim 12 ,
wherein the gate insulating layer contains excess oxygen, wherein a concentration of hydrogen in the gate insulating layer is lower than or equal to 7.2×10 20 atoms/cm 3 , and wherein a concentration of hydrogen in the oxide semiconductor film is lower than or equal to 5×10 19 atoms/cm 3 .

21 . The semiconductor device according to claim 12 , 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.

Assignees

• Semiconductor Energy Lab

Inventors

• Yamazaki Shunpei
• Akimoto Kengo
• Nonaka Yusuke
• Kanemura Hiroshi

Classifications

• H10P14/3434 Primary

  being oxide semiconductor materials (Group IIB-VIA semiconductor materials H10P14/3424) · CPC title

• H10P14/3426

  Oxides · CPC title

• H10P14/2922

  being non-crystalline insulating materials, e.g. glass or polymers · CPC title

• H10P14/22

  using physical deposition, e.g. vacuum deposition or sputtering · CPC title

• H10D62/402

  Amorphous materials · CPC title