NOBLE METAL / NON-NOBLE METAL ELECTRODE FOR RRAM APPLICATIONS
A method for forming a non-volatile memory device includes disposing a junction layer comprising a doped silicon-bearing material in electrical contact with a first conductive material, forming a switching layer comprising an undoped amorphous silicon-bearing material upon at least a portion of the junction layer, disposing a layer comprising a non-noble metal material upon at least a portion of the switching layer, disposing an active metal layer comprising a noble metal material upon at least a portion of the layer, and forming a second conductive material in electrical contact with the active metal layer.
1 . A method for forming a non-volatile memory device comprises:
disposing a junction layer comprising a doped silicon-bearing material in electrical contact with a first conductive material;
forming a switching layer comprising an undoped amorphous silicon-bearing material upon at least a portion of the junction layer;
disposing a layer comprising a non-noble metal material upon at least a portion of the switching layer;
disposing an active metal layer comprising a noble metal material upon at least a portion of the layer; and
forming a second conductive material in electrical contact with the active metal layer.
2 . The method of claim 1 wherein the non-noble metal material is selected from a group consisting of: titanium, aluminum, tungsten, titanium alloy, aluminum alloy, tungsten alloy, titanium nitride, tungsten nitride, aluminum nitride, copper, copper alloy.
3 . The method of claim 1 wherein the noble metal material is selected from a group consisting of: silver, gold, platinum, palladium.
4 . The method of claim 1 wherein the layer comprises an adhesion layer having a thickness within a range of approximately 2 nm to approximately 4 nm.
5 . The method of claim 1 wherein at least a portion of the non-noble metal material oxidizes into an oxidized form of the non-noble metal material after the active metal layer is disposed upon the layer to form an oxidized layer.
6 . The method of claim 5 wherein the oxidized layer has a thickness within a range of approximately 2 nm to approximately 3 nm.
7 . The method of claim 5 wherein oxygen used to oxidize the portion of the non-noble metal material is drawn from the active metal layer.
8 . The method of claim 5
wherein the non-noble metal material comprises titanium-containing material;
wherein the oxidized form of the non-noble metal material comprises titanium dioxide; and
wherein the noble material comprises silver-containing material.
9 . The method of claim 1
wherein the doped silicon-bearing material comprises a p-doped polysilicon material; and
wherein forming the switching layer comprises forming the undoped amorphous silicon-bearing material on top of at least a portion of the p-doped polysilicon material.
10 . The method of claim 9
wherein the switching layer has a thickness within a range of approximately 10 nm to approximately 30 nm.
11 . The method of claim 1
wherein the junction layer includes an upper region; and
wherein the method further comprises subjecting the upper region of the junction layer to an amorphization process to form the undoped amorphous silicon-bearing material.
12 . The method of claim 11 wherein the switching layer has a thickness within a range of approximately 2 nm to approximately 5 nm.
13 . The method of claim 12 wherein the doped silicon-bearing material comprises a material is selected from a group consisting of: doped silicon-germanium, doped polysilicon, p-doped silicon-germanium, and p-doped polysilicon.
14 . A non-volatile memory device formed according to the process described in claim 13 .
15 . A non-volatile memory device comprises:
a junction layer comprising a doped silicon-bearing material electrically coupled to a first conductive material;
a switching layer comprising an undoped amorphous silicon-bearing material formed upon at least a portion of the doped silicon-bearing material;
a first layer comprising a noble metal material disposed above at least a portion of the switching layer;
a second conductive material electrically coupled to the first layer; and
a layer comprising an oxidized form of a non-noble metal material formed between at least a portion of the first layer and at least a portion of the switching layer.
16 . The non-volatile memory device of claim 15 wherein the oxidized form of the non-noble metal material is deposited as a non-oxidized form of the non-noble metal material upon the switching layer.
17 . The non-volatile memory device of claim 15
wherein the non-noble metal material comprises an adhesion material;
wherein the non-noble metal material is selected from a group consisting of:
titanium, aluminum, tungsten, titanium alloy, aluminum alloy, tungsten alloy, titanium nitride, tungsten nitride, aluminum nitride, copper, copper alloy.
18 . The non-volatile memory device of claim 15 wherein the noble metal material is selected from a group consisting of: silver, gold, platinum, palladium.
19 . The non-volatile memory device of claim 15
wherein the undoped amorphous silicon-bearing material is selected from a group consisting of: SiOx, SixGeyOz, where x, y and z are integers; and
wherein the switching layer has a thickness within a range of approximately 2 nm to approximately 5 nm.
20 . The non-volatile memory device of claim 15 wherein the layer has a thickness within a range of approximately 2 nm to approximately 3 nm.