Semiconductor device, display device, input/output device, and electronic device

• US 9,876,099 B2
• Filed: 04/21/2017
• Issued: 01/23/2018
• Est. Priority Date: 06/20/2014
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Jintyou, Masami, Obonai, Toshimitsu, Koezuka, Junichi, Hiraishi, Suzunosuke
• Primary Examiner(s): HENRY, CALEB E
• Application Number:
  US15/493,215
• Publication Number:
  US 20170222028A1
• Time in Patent Office: 277 Days
• Field of Search: 257 40, 257 43, 438 30, 438 46, 438104
• CPC Class Codes: H01L 21/385 using diffusion into or out of a solid from or into a solid phase, e.g. a doped oxide layer
• CPC Class Codes: H01L 21/441 Deposition of conductive or insulating materials for electrodes
• CPC Class Codes: H01L 21/47573 Etching the 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 27/127 with a particular formation, treatment or patterning of the active layer specially adapted to the circuit arrangement
• CPC Class Codes: H01L 29/42384 for thin film field effect transistors, e.g. characterised by the thickness or the shape of the insulator or the dimensions, the shape or the lay-out of the conductor
• CPC Class Codes: H01L 29/4908 for thin film semiconductor, e.g. gate of TFT
• 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 29/78609 for preventing leakage current H01L29/78618 takes precedence
• 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 29/78696 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

To suppress change in electric characteristics and improve reliability of a semiconductor device including a transistor formed using an oxide semiconductor. A semiconductor device includes a transistor including a gate electrode, a first insulating film, an oxide semiconductor film, a second insulating film, and a pair of electrodes. The gate electrode and the oxide semiconductor film overlap with each other. The oxide semiconductor film is located between the first insulating film and the second insulating film and in contact with the pair of electrodes. The first insulating film is located between the gate electrode and the oxide semiconductor film. An etching rate of a region of at least one of the first insulating film and the second insulating film is higher than 8 nm/min when etching is performed using a hydrofluoric acid.

Claims

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

forming a gate electrode;

forming a first insulating film over the gate electrode;

forming an oxide semiconductor film over the first insulating film;

forming a second insulating film over the oxide semiconductor film; and

adding oxygen into the second insulating film,

wherein at least one of the first insulating film and the second insulating film has an etching rate of higher than 8 nm/min when etching is performed using a hydrofluoric acid.

2. The method for manufacturing a semiconductor device according to claim 1, further comprising the step of:

adding oxygen into the first insulating film.

3. The method for manufacturing a semiconductor device according to claim 1, further comprising the steps of:

forming a conductive film over the second insulating film; and

adding oxygen into the second insulating film through the conductive film.

4. The method for manufacturing a semiconductor device according to claim 1, further comprising the step of:

forming a metal oxide film over the first insulating film.

5. The method for manufacturing a semiconductor device according to claim 1, further comprising the step of:

forming a metal oxide film over the second insulating film.

6. The method for manufacturing a semiconductor device according to claim 1, the oxygen is added by an ion implantation method.

7. The method for manufacturing a semiconductor device according to claim 1, wherein both of the first insulating film and the second insulating film has an etching rate of higher than 8 nm/min when etching is performed using the hydrofluoric acid.

8. The method for manufacturing a semiconductor device according to claim 1, wherein the at least one of the first insulating film and the second insulating film has an etching rate of higher than 10 nm/min when etching is performed using the hydrofluoric acid.

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

forming a gate electrode;

forming a first insulating film over the gate electrode;

forming an oxide semiconductor film over the first insulating film;

forming a second insulating film over the oxide semiconductor film; and

adding oxygen into the second insulating film,

wherein at least one of the first insulating film and the second insulating film has an etching rate of higher than 8 nm/min when the at least one of the first insulating film and the second insulating film is immersed in a 0.5 wt/vol % hydrofluoric acid at 24°

C.

10. The method for manufacturing a semiconductor device according to claim 9, further comprising the step of:

adding oxygen into the first insulating film.

11. The method for manufacturing a semiconductor device according to claim 9, further comprising the steps of:

forming a conductive film over the second insulating film; and

adding oxygen into the second insulating film through the conductive film.

12. The method for manufacturing a semiconductor device according to claim 9, further comprising the step of:

forming a metal oxide film over the first insulating film.

13. The method for manufacturing a semiconductor device according to claim 9, further comprising the step of:

forming a metal oxide film over the second insulating film.

14. The method for manufacturing a semiconductor device according to claim 9, the oxygen is added by an ion implantation method.

15. The method for manufacturing a semiconductor device according to claim 9, wherein both of the first insulating film and the second insulating film has an etching rate of higher than 8 nm/min when both of the first insulating film and the second insulating film are immersed in the 0.5 wt/vol % hydrofluoric acid at 24°

C.

16. The method for manufacturing a semiconductor device according to claim 9, wherein the at least one of the first insulating film and the second insulating film has an etching rate of higher than 10 nm/min when the at least one of the first insulating film and the second insulating film is immersed in the 0.5 wt/vol % hydrofluoric acid at 24°

C.