Variable resistance element and memory device

Patent metadata

Field	Value
Publication number	US-10164180-B2
Application number	US-201715704802-A
Country	US
Kind code	B2
Filing date	Sep 14, 2017
Priority date	Nov 21, 2016
Publication date	Dec 25, 2018
Grant date	Dec 25, 2018

Abstract

According to one embodiment, a variable resistance element includes first and second conductive layers and a first layer. The first conductive layer includes at least one of silver, copper, zinc, titanium, vanadium, chrome, manganese, iron, cobalt, nickel, tellurium, or bismuth. The second conductive layer includes at least one of platinum, gold, iridium, tungsten, palladium, rhodium, titanium nitride, or silicon. The first layer includes oxygen and silicon and is provided between the first conductive layer and the second conductive layer. The first layer includes a plurality of holes. The holes are smaller than a thickness of the first layer along a first direction. The first direction is from the second conductive layer toward the first conductive layer. The first layer does not include carbon, or a composition ratio of carbon included in the first layer to silicon included in the first layer is less than 0.1.

First claim

What is claimed is:

1. A variable resistance element, comprising:
a first conductive layer including at least one selected from the group consisting of silver, copper, zinc, titanium, vanadium, chrome, manganese, iron, cobalt, nickel, tellurium, and bismuth;
a second conductive layer including at least one selected from the group consisting of platinum, gold, iridium, tungsten, palladium, rhodium, titanium nitride, and silicon; and
a first layer including oxygen and silicon and being provided between the first conductive layer and the second conductive layer, the first layer including a plurality of holes, the holes being smaller than a thickness of the first layer along a first direction, the first direction being from the second conductive layer toward the first conductive layer, the first layer not including carbon, or a composition ratio of carbon included in the first layer to silicon included in the first layer being less than 0.1.

2. The variable resistance element according to claim 1 , wherein a composition ratio of oxygen included in the first layer to silicon included in the first layer is greater than 2.0 and not more than 2.4.

3. The variable resistance element according to claim 1 , wherein an average length of the plurality of holes along the first direction is not more than 0.5 times the thickness.

4. The variable resistance element according to claim 1 , wherein an average length of the plurality of holes along the first direction is not less than 0.6 nm and not more than 1.5 nm.

5. The variable resistance element according to claim 1 , wherein the thickness is not less than 2 nanometers and not more than 10 nanometers.

6. The variable resistance element according to claim 1 , wherein
the second conductive layer includes at least one of polycrystalline silicon or amorphous silicon,
the polycrystalline silicon includes at least one element selected from the group consisting of boron, arsenic, and phosphorus, and
the amorphous silicon includes the element.

7. The variable resistance element according to claim 1 , wherein a density of the first layer is not less than 1.5 g/cm 3 but less than 2.2 g/cm 3 .

8. The variable resistance element according to claim 1 , wherein the first conductive layer includes at least one selected from the group consisting of silver and copper.

9. The variable resistance element according to claim 1 , further comprising a second layer provided between the first conductive layer and the first layer,
a relative dielectric constant of the second layer being higher than a relative dielectric constant of the first layer.

10. The variable resistance element according to claim 9 , wherein
the second layer includes an oxide or an oxynitride,
the oxide includes at least one selected from the group consisting of aluminum, hafnium, titanium, tantalum, and zirconium, and
the oxynitride includes at least one selected from the group consisting of aluminum, hafnium, titanium, tantalum, zirconium, and silicon.

11. A memory device, comprising:
the variable resistance element according to claim 1 ; and
a controller electrically connected to the first conductive layer and the second conductive layer,
the controller is configured to implement
a first operation of setting a first potential of the first conductive layer to be higher than a second potential of the second conductive layer, and
a second operation of setting the first potential to be lower than the second potential,

a first electrical resistance between the first conductive layer and the second conductive layer after the first operation being lower than a second electrical resistance between the first conductive layer and the second conductive layer after the second operation.

Assignees

• Toshiba Memory Corp

Inventors

• Kuriyama Hiromichi
• Matsubara Yuya
• Harada Kazunori
• Hirohashi Takuya
• Seki Harumi
• Saitoh Masumi

Classifications

• H01L45/146

  Electricity · mapped topic

• G11C2213/52

  Structure characterized by the electrode material, shape, etc. · CPC title

• G11C2013/0078

  Write using current through the cell · CPC title

• G11C2213/56

  Structure including two electrodes, a memory active layer and a so called passive or source or reservoir layer which is NOT an electrode, wherein the passive or source or reservoir layer is a source of ions which migrate afterwards in the memory active layer to be only trapped there, to form conductive filaments there or to react with the material of the memory active layer in redox way · CPC title

• G11C2013/0045

  Read using current through the cell · CPC title