Semiconductor device

• US 9,601,634 B2
• Filed: 12/01/2014
• Issued: 03/21/2017
• Est. Priority Date: 12/02/2013
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Misawa, Chieko, Yokoyama, Yuka, Yamazaki, Shunpei, Katayama, Masahiro, Takahashi, Hironobu, Okazaki, Kenichi
• Primary Examiner(s): Patel, Reema
• Assistant Examiner(s): GHEYAS, SYED I
• Application Number:
  US14/556,769
• Publication Number:
  US 20150155387A1
• Time in Patent Office: 841 Days
• Field of Search: 257/43
• US Class Current: 1/1
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• 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 29/66969 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 29/78606 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

Abstract

A highly reliable semiconductor device which uses an oxide semiconductor film for a backplane is provided. A semiconductor device includes a first conductive film, a first insulating film over the first conductive film, an oxide semiconductor film which is over the first insulating film and overlaps with the first conductive film, a second insulating film over the oxide semiconductor film, and a pair of second conductive films electrically connected to the oxide semiconductor film through an opening portion included in the second insulating film. The second insulating film overlaps with a region of the oxide insulating film in which a carrier flows between the pair of second conductive films and overlaps with end portions of the oxide semiconductor film.

Claims

1. A semiconductor device comprising:

a first insulating film;

an oxide semiconductor film comprising a channel formation region over the first insulating film;

a second insulating film over the oxide semiconductor film and comprising a first opening and a second opening; and

a pair of conductive films electrically connected to the oxide semiconductor film respectively through the first opening and the second opening,

wherein the second insulating film has a stacked-layer structure including a first film and a second film over the first film,

wherein the second insulating film overlaps the channel formation region and an end portion of the oxide semiconductor film, and

wherein the first film is in contact with a top surface of the channel formation region of the oxide semiconductor film, a side edge of the end portion of the oxide semiconductor film and the first insulating film.

2. The semiconductor device according to claim 1, wherein each of the first film and the second film comprises silicon and nitrogen.

3. The semiconductor device according to claim 1,

wherein the oxide semiconductor film comprises a first region below the first opening and a second region below the second opening,

wherein the channel formation region is located between the first region and the second region, and

wherein each thickness of the first region and the second region is smaller than each thickness of the channel formation region and the end portion.

4. The semiconductor device according to claim 1, wherein the oxide semiconductor film comprises indium, zinc and a metal other than indium and zinc.

5. The semiconductor device according to claim 1, further comprising a second conductive film overlapping the channel formation region.

6. The semiconductor device according to claim 5, wherein the second conductive film overlaps the end portion of the oxide semiconductor film.

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

8. The semiconductor device according to claim 1,

wherein the second film having excess oxygen, and

wherein the second film contains more oxygen than the first film.

9. The semiconductor device according to claim 1,

wherein the second film has a spin density of 3×

10¹⁷ spins/cm³ or less corresponding to a signal at a g-factor of 2.001 in electron spin resonance spectroscopy is used.

10. A semiconductor device comprising:

a first conductive film;

a first insulating film over the first conductive film;

an oxide semiconductor film comprising a channel formation region overlapping the first conductive film with the first insulating film therebetween;

a second insulating film over the oxide semiconductor film and comprising a first opening and a second opening;

a pair of second conductive films electrically connected to the oxide semiconductor film respectively through the first opening and the second opening;

a third insulating film comprising silicon and nitrogen over the oxide semiconductor film and the pair of second conductive films; and

a fourth insulating film comprising silicon and oxygen over the third insulating film,

wherein the second insulating film has a stacked-layer structure including a first film and a second film over the first film,

wherein the second insulating film overlaps the channel formation region and an end portion of the oxide semiconductor film, and

wherein the first film is in contact with a top surface of the channel formation region of the oxide semiconductor film, a side edge of the end portion of the oxide semiconductor film and the first insulating film.

11. The semiconductor device according to claim 10, wherein each of the first film and the second film comprises silicon and nitrogen.

12. The semiconductor device according to claim 10,

wherein the oxide semiconductor film comprises a first region below the first opening and a second region below the second opening,

wherein the channel formation region is located between the first region and the second region, and

wherein each thickness of the first region and the second region is smaller than each thickness of the channel formation region and the end portion.

13. The semiconductor device according to claim 10, wherein the oxide semiconductor film comprises indium, zinc and a metal other than indium and zinc.

14. The semiconductor device according to claim 10, further comprising a fifth insulating film between the pair of second conductive films and the third insulating film.

15. An electronic device including the semiconductor device according to claim 10.

16. The semiconductor device according to claim 10,

wherein the second film having excess oxygen, and

wherein the second film contains more oxygen than the first film.

17. The semiconductor device according to claim 10,

wherein the second film has a spin density of 3×

10¹⁷ spins/cm³ or less corresponding to a signal at a g-factor of 2.001 in electron spin resonance spectroscopy is used.

18. A semiconductor device comprising:

a first conductive film;

a first insulating film over the first conductive film;

an oxide semiconductor film comprising a channel formation region overlapping the first conductive film with the first insulating film therebetween;

a second insulating film over the oxide semiconductor film and comprising a first opening and a second opening;

a pair of second conductive films electrically connected to the oxide semiconductor film respectively through the first opening and the second opening;

a third insulating film over the oxide semiconductor film and the pair of second conductive films;

a fourth insulating film over the third insulating film; and

a third conductive film overlapping the channel formation region with the third insulating film and the fourth insulating film therebetween,

wherein the second insulating film has a stacked-layer structure including a first film and a second film over the first film,

wherein the second insulating film overlaps the channel formation region and an end portion of the oxide semiconductor film,

wherein the first film is in contact with a top surface of the channel formation region of the oxide semiconductor film, a side edge of the end portion of the oxide semiconductor film and the first insulating film, and

wherein the third conductive film is electrically connected to the first conductive film through a third opening provided in the second to fourth insulating films.

19. The semiconductor device according to claim 18, wherein each of the first film and the second film comprises silicon and nitrogen.

20. The semiconductor device according to claim 18,

wherein the oxide semiconductor film comprises a first region below the first opening and a second region below the second opening,

wherein the channel formation region is located between the first region and the second region, and

wherein each thickness of the first region and the second region is smaller than each thickness of the channel formation region and the end portion.

21. The semiconductor device according to claim 18, wherein the oxide semiconductor film comprises indium, zinc and a metal other than indium and zinc.

22. The semiconductor device according to claim 18, wherein the third conductive film overlaps the end portion of the oxide semiconductor film.

23. The semiconductor device according to claim 18, further comprising a fifth insulating film between the pair of second conductive films and the third insulating film.

24. An electronic device including the semiconductor device according to claim 18.

25. The semiconductor device according to claim 18,

wherein the second film having excess oxygen, and

wherein the second film contains more oxygen than the first film.

26. The semiconductor device according to claim 18,

wherein the second film has a spin density of 3×

10¹⁷ spins/cm³ or less corresponding to a signal at a g-factor of 2.001 in electron spin resonance spectroscopy is used.