PROGRAMMABLE RESISTANCE MEMORY ELEMENTS WITH ELECTRODE INTERFACE LAYER AND MEMORY DEVICES INCLUDING THE SAME
A memory element can include a first electrode comprising at least a first element; a second electrode formed of a conductive material; and a memory layer comprising a memory material programmable between different resistance states. The first element can be ion conductible within the memory material. A second electrode can include an interface layer in contact with the memory layer. The interface layer being formed by inclusion of at least one modifier element not present in a remainder of the second electrode and not ion conductible within the memory material.
1 . A memory element, comprising:
a first electrode comprising at least a first element;
a second electrode formed of a conductive material; and
a memory layer disposed between the first electrode and a second electrode, the memory layer comprising a memory material programmable between different resistance states, the first element being ion conductible within the memory material; wherein
the second electrode includes an interface layer on a surface of the second electrode in contact with the memory layer, the interface layer formed by inclusion of at least one modifier element not present in a remainder of the second electrode, the modifier element not being ion conductible within the memory material.
2 . The memory element of claim 1 , wherein:
the modifier element is a non-metal.
3 . The memory element of claim 2 , wherein:
the modifier element is nitrogen.
4 . The memory element of claim 2 , wherein:
the modifier element is oxygen.
5 . The memory element of claim 4 , wherein:
the second electrode comprises a metal; and
the interface layer comprises an oxide of the metal.
6 . The memory element of claim 2 , wherein:
the modifier element is a semiconductor that is not included in the memory material.
7 . The memory element of claim 1 , wherein:
the interface layer has a thickness less than one half the thickness of the memory layer.
8 . A memory element, comprising:
a first electrode comprising at least a first element;
a second electrode comprising at least second element;
a memory layer disposed between the first electrode and a second electrode, the memory layer comprising a memory material programmable between different resistance states, the first element being ion conductible within the memory material; and
an interface layer on a surface of the second electrode in contact with the memory layer, the interface layer formed by inclusion of at least one modifier element not present in a remainder of the second electrode, the modifier element being a non-metal.
9 . The memory element of claim 8 , wherein:
the modifier element is selected from the group of: oxygen and nitrogen.
10 . The memory element of claim 9 , wherein:
the interface layer comprises an oxide of the second element.
11 . The memory element of claim 9 , wherein:
the interface layer comprises a nitride of the second element.
12 . The memory element of claim 8 , wherein:
the modifier element is a semiconductor.
13 . The memory element of claim 8 , wherein:
the first electrode, second electrode and memory layer are vertically stacked, the first electrode being a top electrode and the second electrode being a bottom electrode.
14 . A method, comprising:
forming a first electrode;
forming an interface layer that extends into the first electrode by inclusion of at least one modifier element not present in a remainder of the second electrode;
forming a memory layer in contact with the interface layer, the memory layer comprising a memory material programmable between different resistance states; and
forming a second electrode comprising a first element that is ion conductible within the memory material; wherein the modifier element is not ion conductible within the memory material.
15 . The method of claim 14 , wherein:
forming the interface layer includes treating an exposed surface of the first electrode.
16 . The method of claim 15 , wherein:
treating the exposed surface of the first electrode includes subjecting the surface to a temperature cycle.
17 . The method of claim 15 , wherein:
treating the exposed surface of the first electrode includes oxidizing the surface.
18 . The method of claim 15 , wherein:
treating the exposed surface of the first electrode includes implanting atoms of the modifier element into the surface.
19 . The method of claim 15 , wherein:
treating the exposed surface of the first electrode includes exposing the surface to a plasma that includes a gas comprising the modifier element.
20 . The method of claim 14 , wherein:
forming the interface layer includes adding the modifier element in situ as the first electrode is formed.