Resistance change device, and method for producing same

Patent metadata

Field	Value
Publication number	US-9343207-B2
Application number	US-201314369659-A
Country	US
Kind code	B2
Filing date	Aug 27, 2013
Priority date	Sep 5, 2012
Publication date	May 17, 2016
Grant date	May 17, 2016

Abstract

To provide a resistance change device that can be protected from an excess current without enlarging a device size. A resistance change device 1 according to the present embodiment includes a lower electrode layer 3 , an upper electrode layer 6 , a first metal oxide layer 51 , a second metal oxide layer 52 , and a current limiting layer 4 . The first metal oxide layer 51 is disposed between the lower electrode layer 3 and the upper electrode layer 6 , and has a first resistivity. The second metal oxide layer 52 is disposed between the first metal oxide layer 51 and the upper electrode layer 6 , and has a second resistivity higher than the first resistivity. The current limiting layer 4 is disposed between the lower electrode layer 3 and the first metal oxide layer 51 , and has a third resistivity higher than the first resistivity and lower than the second resistivity.

First claim

The invention claimed is:

1. A resistance change device, comprising:
a first electrode;
a second electrode;
a first metal oxide layer having a first resistivity and being disposed between the first electrode and the second electrode;
a second metal oxide layer having a second resistivity higher than the first resistivity and being disposed between the first metal oxide layer and the second electrode; and
a current limiting layer having a third resistivity higher than the first resistivity and lower than the second resistivity and being disposed between the first electrode and the first metal oxide layer, the third resistivity being higher than 1×10 5 Ω·cm and not higher than 3×10 6 Ω·cm.

2. The resistance change device according to claim 1 , wherein the current limiting layer is composed of a metal oxide.

3. The resistance change device according to claim 2 , wherein the current limiting layer is composed of a metal oxide including an oxygen defect, and is in an ohmic contact with the first electrode.

4. The resistance change device according to claim 3 , wherein
the first metal oxide layer is composed of a metal oxide including an oxygen defect, and
the second metal oxide layer is composed of a metal oxide having a stoichiometric composition.

5. The resistance change device according to claim 2 , wherein
the first metal oxide layer is composed of a metal oxide including an oxygen defect, and
the second metal oxide layer is composed of a metal oxide having a stoichiometric composition.

6. The resistance change device according to claim 1 , wherein
the current limiting layer is composed of a metal oxide including an oxygen defect, and is in an ohmic contact with the first electrode.

7. The resistance change device according to claim 6 , wherein
the first metal oxide layer is composed of a metal oxide including an oxygen defect, and
the second metal oxide layer is composed of a metal oxide having a stoichiometric composition.

8. The resistance change device according to claim 1 , wherein
the first metal oxide layer is composed of a metal oxide including an oxygen defect, and
the second metal oxide layer is composed of a metal oxide having a stoichiometric composition.

9. A method of producing a resistance change device, comprising:
forming a first electrode;
forming, by a reactive sputtering method, a current limiting layer composed of a metal oxide having a third resistivity higher than a first resistivity and lower than a second resistivity on the first electrode, the third resistivity being higher than 1×10 5 Ω·cm and not higher than 3×10 6 Ω·cm;
forming a first metal oxide layer having the first resistivity on the current limiting layer;
forming a second metal oxide layer having the second resistivity on the first metal oxide layer; and
forming a second electrode on the second metal oxide layer.

10. The method according to claim 9 , wherein the first metal oxide layer and the second metal oxide layer are formed by a reactive sputtering method under oxygen atmosphere.

Assignees

• Fukuda Natsuki
• Fukuju Kazunori
• Nishioka Yutaka
• Suu Koukou
• Ulvac Inc

Inventors

• Fukuda Natsuki
• Fukuju Kazunori
• Nishioka Yutaka
• Suu Koukou

Classifications

• H01C17/06

  adapted for coating resistive material on a base · CPC title

• C23C14/08

  Oxides (C23C14/10 takes precedence) · CPC title

• H01C17/12

  by sputtering · CPC title

• H01C7/108 Primary

  Metal oxide · CPC title

• C23C14/0036

  Reactive sputtering · CPC title