Semiconductor device and manufacturing method thereof

• US 10,535,776 B2
• Filed: 04/06/2017
• Issued: 01/14/2020
• Est. Priority Date: 10/19/2011
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei, Hayakawa, Masahiko, Honda, Tatsuya
• Primary Examiner(s): Galvin, III, Joseph M
• Application Number:
  US15/480,746
• Publication Number:
  US 20170213914A1
• Time in Patent Office: 1,013 Days
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: G02F 2203/01 transmissive
• CPC Class Codes: G02F 2203/64 Normally black display, i.e. the off state being black
• 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 27/14616 characterised by the channel of the transistor, e.g. channel having a doping gradient
• 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 29/45 Ohmic electrodes
• CPC Class Codes: H01L 29/49 Metal-insulator-semiconductor electrodes, e.g. gates of MOSFET H01L29/435 takes precedence
• CPC Class Codes: H01L 29/66742 Thin film unipolar transistors
• 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 29/78618 characterised by the drain or the source properties, e.g. the doping structure, the composition, the sectional shape or the contact structure silicide contacts, electrodes in general H01L29/458
• 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 29/78696 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
• CPC Class Codes: H10K 59/1213 the pixel elements being TFTs

Abstract

When a semiconductor device including a transistor in which a gate electrode layer, a gate insulating film, and an oxide semiconductor film are stacked and a source and drain electrode layers are provided in contact with the oxide semiconductor film is manufactured, after the formation of the gate electrode layer or the source and drain electrode layers by an etching step, a step of removing a residue remaining by the etching step and existing on a surface of the gate electrode layer or a surface of the oxide semiconductor film and in the vicinity of the surface is performed. The surface density of the residue on the surface of the oxide semiconductor film or the gate electrode layer can be 1×10¹³ atoms/cm² or lower.

Claims

1. A semiconductor device comprising:

a first insulating film;

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

a second insulating film over the oxide semiconductor film,

wherein a concentration of an element of an etchant on a top surface of the oxide semiconductor film is 5×

10¹⁸ atoms/cm³ or lower,

wherein the top surface of the oxide semiconductor film is in contact with the second insulating film, and

wherein a bottom surface of the oxide semiconductor film is in contact with the first insulating film.

2. The semiconductor device according to claim 1, wherein the oxide semiconductor film comprises indium, gallium and zinc.

3. The semiconductor device according to claim 1, wherein the oxide semiconductor film comprises a recessed portion on the top surface.

4. An electronic device comprising the semiconductor device according to claim 1,

wherein the electronic device is any one of a television set, a monitor, a camera, a digital photo frame, a mobile phone, a game machine, an audio reproducing device, and a portable information terminal.

5. A semiconductor device comprising:

a first insulating film;

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

a second insulating film over the oxide semiconductor film,

wherein a concentration of an element of a resist mask on a top surface of the oxide semiconductor film is 5×

10¹⁸ atoms/cm³ or lower,

wherein the top surface of the oxide semiconductor film is in contact with the second insulating film, and

wherein a bottom surface of the oxide semiconductor film is in contact with the first insulating film.

6. The semiconductor device according to claim 5, wherein the oxide semiconductor film comprises indium, gallium and zinc.

7. The semiconductor device according to claim 5, wherein the oxide semiconductor film comprises a recessed portion on the top surface.

8. An electronic device comprising the semiconductor device according to claim 5,

wherein the electronic device is any one of a television set, a monitor, a camera, a digital photo frame, a mobile phone, a game machine, an audio reproducing device, and a portable information terminal.

9. A semiconductor device comprising:

a first insulating film;

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

a source electrode over and electrically connected to the oxide semiconductor film, the source electrode comprising metal;

a drain electrode over and electrically connected to the oxide semiconductor film, the drain electrode comprising the metal; and

a second insulating film over the oxide semiconductor film, the source electrode, and the drain electrode, the second insulating film being in contact with a top surface of the oxide semiconductor film,

wherein a concentration of the metal on the top surface of the oxide semiconductor film is 5×

10¹⁸ atoms/cm³ or lower, and

wherein a bottom surface of the oxide semiconductor film is in contact with the first insulating film.

10. The semiconductor device according to claim 9, wherein the oxide semiconductor film comprises indium, gallium and zinc.

11. The semiconductor device according to claim 9, wherein the oxide semiconductor film comprises a recessed portion between the source electrode and the drain electrode.

12. The semiconductor device according to claim 9, wherein frequency of refresh operation of the semiconductor device is changeable.

13. The semiconductor device according to claim 9, wherein frequency of refresh operation of the semiconductor device is able to be reduced.

14. The semiconductor device according to claim 9, wherein the metal is Al.

15. The semiconductor device according to claim 9, wherein the metal is Cr.

16. The semiconductor device according to claim 9, wherein the metal is Cu.

17. The semiconductor device according to claim 9, wherein the metal is Ta.

18. The semiconductor device according to claim 9, wherein the metal is Ti.

19. The semiconductor device according to claim 9, wherein the metal is Mo.

20. The semiconductor device according to claim 9, wherein the metal is W.

21. An electronic device comprising the semiconductor device according to claim 9,

wherein the electronic device is any one of a television set, a monitor, a camera, a digital photo frame, a mobile phone, a game machine, an audio reproducing device, and a portable information terminal.

22. A semiconductor device comprising:

a substrate comprising an insulating surface;

a gate electrode layer over the insulating surface;

a gate insulating film over the gate electrode layer;

an oxide semiconductor film over and in direct contact with the gate insulating film;

a source electrode layer electrically connected to the oxide semiconductor film;

a drain electrode layer electrically connected to the oxide semiconductor film; and

an insulating film in direct contact with a top surface of the oxide semiconductor film,

wherein a concentration of boron on the top surface of the oxide semiconductor film is 5×

10¹⁸ atoms/cm³ or lower,

wherein a concentration of boron on a top surface of the gate electrode layer is 5×

10¹⁸ atoms/cm³ or lower, and wherein the oxide semiconductor film comprises indium, gallium and zinc.

23. The semiconductor device according to claim 22, wherein the concentration of boron on the top surface of the oxide semiconductor film is 1×

10¹⁸ atoms/cm³ or lower.

24. The semiconductor device according to claim 22, wherein the concentration of boron on the top surface of the gate electrode layer is 1×

10¹⁸ atoms/cm³ or lower.

25. A semiconductor device comprising:

a substrate comprising an insulating surface;

a gate electrode layer over the insulating surface;

a gate insulating film over the gate electrode layer;

an oxide semiconductor film over and in direct contact with the gate insulating film;

a source electrode layer electrically connected to the oxide semiconductor film;

a drain electrode layer electrically connected to the oxide semiconductor film; and

an insulating film in direct contact with a top surface of the oxide semiconductor film,

wherein a concentration of aluminum on the top surface of the oxide semiconductor film is 5×

10¹⁸ atoms/cm³ or lower,

wherein a concentration of aluminum on a top surface of the gate electrode layer is 5×

10¹⁸ atoms/cm³ or lower, and

wherein the oxide semiconductor film comprises indium, gallium and zinc.

26. The semiconductor device according to claim 25, wherein the concentration of aluminum on the top surface of the oxide semiconductor film is 1×

10¹⁸ atoms/cm³ or lower.

27. The semiconductor device according to claim 25, wherein the concentration of aluminum on the top surface of the gate electrode layer is 1×

10¹⁸ atoms/cm³ or lower.