Semiconductor device

• US 8,853,697 B2
• Filed: 02/26/2013
• Issued: 10/07/2014
• Est. Priority Date: 03/01/2012
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.), Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.), Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Okazaki, Kenichi, Matsuo, Takuya, Yamamoto, Yoshitaka, Matsukizono, Hiroshi, Kanzaki, Yosuke
• Primary Examiner(s): Pham, Hoai V
• Application Number:
  US13/776,999
• Publication Number:
  US 20130228774A1
• Time in Patent Office: 588 Days
• Field of Search: 257/59, 257/66, 257/72, 257/347, 257/E29.117, 257/E29.273
• US Class Current: 257/59
• CPC Class Codes: H01L 29/78603 characterised by the insulating substrate or support H01L29/78657 takes 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

To inhibit a metal element contained in a glass substrate from being diffused into a gate insulating film or an oxide semiconductor film. A semiconductor device includes a glass substrate, a base insulating film formed using metal oxide over the glass substrate, a gate electrode formed over the base insulating film, a gate insulating film formed over the gate electrode, an oxide semiconductor film which is formed over the gate insulating film and overlapping with the gate electrode, and a source electrode and a drain electrode which are electrically connected to the oxide semiconductor film. In a region of the base insulating film that is present in a range of 3 nm or less from a surface of the base insulating film, the concentration of a metal element contained in the glass substrate is less than or equal to 1×10¹⁸ atoms/cm³.

Claims

1. A semiconductor device comprising:

a glass substrate containing a metal element;

an oxide semiconductor film over the glass substrate; and

an insulating film including metal oxide between the oxide semiconductor film and the glass substrate,

wherein the insulating film includes a region in a range of 3 nm or less from a top surface of the insulating film, and

wherein a concentration of the metal element in the region is less than or equal to 1×

10¹⁸ atoms/cm³.

2. The semiconductor device according to claim 1, further comprising an oxide insulating film over a channel region of the oxide semiconductor film.

3. The semiconductor device according to claim 1,

wherein the insulating film is an aluminum oxide film, and

wherein a density of the aluminum oxide film is 3.2 g/cm³ or more.

4. The semiconductor device according to claim 3,

wherein an amount of water released from the aluminum oxide film is less than or equal to 1.0×

10¹⁵ atoms/cm³.

5. The semiconductor device according to claim 3,

wherein an amount of hydrogen released from the aluminum oxide film is less than or equal to 1.0×

10¹⁵ atoms/cm³.

6. The semiconductor device according to claim 1,

wherein the oxide semiconductor film is a film containing at least one oxide selected from the group consisting of indium oxide, zinc oxide, gallium oxide, and tin oxide.

7. The semiconductor device according to claim 1,

wherein the oxide semiconductor film contains a crystal part, and

wherein, in the crystal part, a c-axis is aligned in a direction parallel to a normal vector of a surface where the oxide semiconductor film is formed.

8. A semiconductor device comprising:

a glass substrate containing a metal element;

a base insulating film including metal oxide over the glass substrate;

a gate electrode over the base insulating film;

a gate insulating film over the gate electrode;

an oxide semiconductor film over the gate electrode with the gate insulating film interposed therebetween; and

a source electrode and a drain electrode which are electrically connected to the oxide semiconductor film,

wherein the base insulating film includes a region in a range of 3 nm or less from a top surface of the base insulating film, and

wherein a concentration of the metal element in the region is less than or equal to 1×

10¹⁸ atoms/cm³.

9. The semiconductor device according to claim 8, further comprising an oxide insulating film over a channel region of the oxide semiconductor film.

10. The semiconductor device according to claim 8,

wherein the base insulating film is an aluminum oxide film, and

wherein a density of the aluminum oxide film is 3.2 g/cm³ or more.

11. The semiconductor device according to claim 10,

wherein an amount of water released from the aluminum oxide film is less than or equal to 1.0×

10¹⁵ atoms/cm³.

12. The semiconductor device according to claim 10,

wherein an amount of hydrogen released from the aluminum oxide film is less than or equal to 1.0×

10¹⁵ atoms/cm³.

13. The semiconductor device according to claim 8,

wherein the oxide semiconductor film is a film containing at least one oxide selected from the group consisting of indium oxide, zinc oxide, gallium oxide, and tin oxide.

14. The semiconductor device according to claim 8,

wherein the oxide semiconductor film contains a crystal part, and

wherein, in the crystal part, a c-axis is aligned in a direction parallel to a normal vector of a surface where the oxide semiconductor film is formed.

15. A semiconductor device comprising:

a glass substrate containing a metal element;

a gate electrode formed over the glass substrate;

a first gate insulating film including metal oxide over the gate electrode;

a second gate insulating film over the first gate insulating film, the second gate insulating film having a different composition from the first gate insulating film;

an oxide semiconductor film over the gate electrode with the first gate insulating film and the second gate insulating film interposed therebetween; and

a source electrode and a drain electrode which are electrically connected to the oxide semiconductor film,

wherein the first gate insulating film includes a region in a range of 3 nm or less from a top surface of the first gate insulating film, and

wherein a concentration of the metal element in the region is less than or equal to 1×

10¹⁸ atoms/cm³.

16. The semiconductor device according to claim 15, further comprising an oxide insulating film over a channel region of the oxide semiconductor film.

17. The semiconductor device according to claim 15,

wherein the first gate insulating film is an aluminum oxide film, and

wherein a density of the aluminum oxide film is 3.2 g/cm³ or more.

18. The semiconductor device according to claim 17,

wherein an amount of water released from the aluminum oxide film is less than or equal to 1.0×

10¹⁵ atoms/cm³.

19. The semiconductor device according to claim 17,

wherein an amount of hydrogen released from the aluminum oxide film is less than or equal to 1.0×

10¹⁵ atoms/cm³.

20. The semiconductor device according to claim 15,

wherein the oxide semiconductor film is a film containing at least one oxide selected from the group consisting of indium oxide, zinc oxide, gallium oxide, and tin oxide.

21. The semiconductor device according to claim 15,

wherein the oxide semiconductor film contains a crystal part, and

wherein, in the crystal part, a c-axis is aligned in a direction parallel to a normal vector of a surface where the oxide semiconductor film is formed.