SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING SAME

• US 20120097916A1
• Filed: 06/21/2010
• Published: 04/26/2012
• Est. Priority Date: 06/25/2009
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Tada, Munehiro, Sakamoto, Toshitsugu, Hada, Hiromitsu
• Granted Patent: US 9,059,028 B2
• Time in Patent Office: Days
• US Class Current: 257/4
• CPC Class Codes: H10B 63/30 comprising selection components having three or more electrodes, e.g. transistors
• CPC Class Codes: H10B 63/34 of the vertical channel field-effect transistor type
• CPC Class Codes: H10B 63/84 arranged in a direction perpendicular to the substrate, e.g. 3D cell arrays
• CPC Class Codes: H10N 70/023 by chemical vapor deposition, e.g. MOCVD, ALD
• CPC Class Codes: H10N 70/026 by physical vapor deposition, e.g. sputtering
• CPC Class Codes: H10N 70/063 by etching of pre-deposited switching material layers, e.g. lithography
• CPC Class Codes: H10N 70/245 the species being metal cations, e.g. programmable metallization cells
• CPC Class Codes: H10N 70/801 Constructional details of multistable switching devices
• CPC Class Codes: H10N 70/826 adapted for essentially vertical current flow, e.g. sandwich or pillar type devices
• CPC Class Codes: H10N 70/883 Oxides or nitrides

Abstract

The objective of the present invention is to provide a semiconductor device provided with a resistance-variable element having sufficient switching property and exhibiting high reliability and high densification as well as good insulating property.

The present invention provides a semiconductor device comprising a resistance-variable element provided within multiple wiring layers on a semiconductor substrate, wherein the resistance-variable element comprises a laminated structure in which a first electrode, a first ion-conductive layer of valve-metal oxide film, a second ion-conductive layer containing oxygen and a second electrode are laminated in this order, and the wiring of the multiple wiring layers also serves as the first electrode.

Claims

1. A semiconductor device comprising a resistance-variable element provided within multiple wiring layers on a semiconductor substrate, wherein

the resistance-variable element comprises a laminated structure in which a first electrode, a first ion-conductive layer composedof an oxide film of valve-metal, a second ion-conductive layer containing oxygen and a second electrode are laminated in this order, and

a wiring of the multiple wiring layers also serves as the first electrode.

2. The semiconductor device according to claim 1, wherein

an insulating barrier film is interposed between the first electrode and the first ion-conductive layer,

the insulating barrier film has an opening, and

the first ion-conductive layer is contacted with the first electrode at the opening.

3. The semiconductor device according to claim 1, wherein the first electrode comprises copper.

4. The semiconductor device according to claim 1, wherein the oxide film of valve-metal is a titanium oxide film or an aluminum oxide film.

5. The semiconductor device according to claim 4, wherein the oxide film of valve-metal is a titanium oxide film, and the thickness of the titanium oxide film is 4 nm or less.

6. The semiconductor device according to claim 1, wherein the second ion-conductive layer is an oxide primarily containing at least one of Ta, Zr and Hf.

7. The semiconductor device according to claim 6, wherein the second ion-conductive layer is a composite oxide of Ta and Si.

8. The semiconductor device according to claim 6, wherein the second ion-conductive layer is a composite oxide of Zr and Si.

9. The semiconductor device according to claim 6, wherein the second ion-conductive layer is a composite oxide of Hf and Si.

10. The semiconductor device according to claim 7, wherein

the oxide film of valve-metal is a titanium oxide film, and the thickness of the titanium oxide film is 4 nm or less, and

the total film thickness of a laminated structure comprising the titanium oxide and the composite oxide of Ta and Si is 20 nm or less.

11. The semiconductor device according to claim 1, wherein

the multiple wiring layers further has a plug connected electrically to the second electrode,

the second electrode comprises a first upper electrode in contact with the second ion-conductive layer and a second upper electrode in contact with the plug, and

the first upper electrode comprises Ru or Ni.

12. The semiconductor device according to claim 11, wherein the second upper electrode comprises Ti, Ta, W, or nitrides thereof.

13. A method for manufacturing the semiconductor device according to claim 1, comprising the steps of:

forming a valve-metal film on the first electrode, and

oxidizing the valve-metal film while forming the second ion-conductive layer under the presence of oxygen.

14. The method for manufacturing the semiconductor device according to claim 13, wherein the ion-conductive layer is formed by a sputtering or ALD method.

15. The method for manufacturing the semiconductor device according to claim 14, wherein the valve-metal film is a titanium film, and the thickness of the titanium film is 2 nm or less.

16. The method for manufacturing the semiconductor device according to claim 13, wherein the second ion-conductive layer is formed using TaSiO as a target under the presence of oxygen by a high frequency sputtering method.

17. The method for manufacturing the semiconductor device according to claim 16, wherein the high frequency sputtering method is performed using a mixed gas of oxygen and argon.