Semiconductor device comprising oxide semiconductor

• US 9,634,031 B2
• Filed: 06/17/2015
• Issued: 04/25/2017
• 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:
  US14/741,840
• Publication Number:
  US 20150372023A1
• Time in Patent Office: 678 Days
• Field of Search: 257 43
• 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 semiconductor device comprising:

a transistor including;

a gate electrode;

a first insulating film;

an oxide semiconductor film;

a second insulating film; and

a pair of electrodes,

wherein the oxide semiconductor film is located between the first insulating film and the second insulating film,

wherein the oxide semiconductor film is in contact with the pair of electrodes,

wherein the first insulating film is located between the gate electrode and the oxide semiconductor film,

wherein silicon and oxygen are contained in at least one of the first insulating film and the second insulating film, and

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 a hydrofluoric acid.

2. The semiconductor device according to claim 1,

wherein the gate electrode is located between a substrate and the oxide semiconductor film,

wherein the second insulating film over the oxide semiconductor film is in contact with a film,

wherein the second insulating film is located between the oxide semiconductor film and the film, and

wherein the film includes oxygen and at least one of indium, zinc, titanium, aluminum, tungsten, tantalum, and molybdenum.

3. The semiconductor device according to claim 1,

wherein the oxide semiconductor film is located between a substrate and the gate electrode,

wherein the transistor includes a third film,

wherein the third film is located between the first insulating film and the gate electrode, and

wherein the third film includes oxygen and at least one of indium, zinc, titanium, aluminum, tungsten, tantalum, and molybdenum.

4. The semiconductor device according to claim 1,

wherein the oxide semiconductor film is located between a substrate and the gate electrode,

wherein the second insulating film located between the substrate and the oxide semiconductor film is in contact with a fourth film,

wherein the fourth film is located between the second insulating film and the oxide semiconductor film, and

wherein the fourth film includes oxygen and at least one of indium, zinc, titanium, aluminum, tungsten, tantalum, and molybdenum.

5. The semiconductor device according to claim 1,

wherein a temperature of the hydrofluoric acid at the etching is 24°

C., and

wherein a concentration of the hydrofluoric acid is 0.5 wt/vol %.

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

7. The semiconductor device according to claim 1,

wherein both of the first insulating film and the second insulating film have an etching rate of higher than 10 nm/min when etching is performed using the hydrofluoric acid.

8. A display device comprising:

the semiconductor device according to claim 1; and

a pixel electrode,

wherein the pixel electrode is electrically connected to the transistor.

9. An input/output device comprising:

the semiconductor device according to claim 1; and

a touch panel,

wherein the touch panel is electrically connected to the semiconductor device.

10. A semiconductor device comprising,

a transistor including:

a gate electrode;

a first insulating film;

a first film;

an oxide semiconductor film;

a second insulating film; and

a pair of electrodes,

wherein the gate electrode is located between a substrate and the oxide semiconductor film,

wherein the first insulating film is located between the gate electrode and the oxide semiconductor film,

wherein the first film is located between the first insulating film and the oxide semiconductor film,

wherein the oxide semiconductor film is in contact with the pair of electrodes,

wherein the first film includes oxygen and at least one of indium, zinc, titanium, aluminum, tungsten, tantalum, and molybdenum, and

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.

11. The semiconductor device according to claim 10,

wherein a temperature of the hydrofluoric acid at the etching is 24°

C., and

wherein a concentration of the hydrofluoric acid is 0.5 wt/vol %.

12. The semiconductor device according to claim 10, wherein both of the first insulating film and the second insulating film have an etching rate of higher than 8 nm/min when etching is performed using the hydrofluoric acid.

13. The semiconductor device according to claim 10,

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.

14. A display device comprising:

the semiconductor device according to claim 10; and

a pixel electrode,

wherein the pixel electrode is electrically connected to the transistor.

15. An input/output device comprising:

the semiconductor device according to claim 10; and

a touch panel,

wherein the touch panel is electrically connected to the semiconductor device.