Fabrication and operation of correlated electron material devices

Patent metadata

Field	Value
Publication number	US-2017213960-A1
Application number	US-201615385719-A
Country	US
Kind code	A1
Filing date	Dec 20, 2016
Priority date	Jan 26, 2016
Publication date	Jul 27, 2017
Grant date	—

Abstract

Subject matter disclosed herein may relate to fabrication of correlated electron materials used, for example, to perform a switching function. In embodiments, a correlated electron material may comprise a dominant ligand and a substitutional ligand, which may permit electron donation and back-donation in a correlated electron material. Electron donation and back-donation may enable the correlated electron material to exhibit a transition from high impedance/insulative state to a low impedance conductive state.

First claim

What is claimed is:

1 . A method of constructing a device, comprising:
forming, in a chamber, one or more layers of correlated electron material (CEM) on a substrate, the one or more layers of CEM being formed from a transition metal and a dominant ligand, the one or more layers of CEM having a concentration of defects in the coordination spheres forming the CEM; and exposing the one or more layers of CEM to a molecular dopant comprising a substitutional ligand to form a P-type CEM, wherein the molecular dopant comprises one or more of: O 2 2− (oxygen), I − (iodide ion), Br − (bromide ion), S 2− (sulfur), SCN − (thiocyanate ion, [SCM] − (sulfur-carbon-nitrogen ligand with carbon between), Cl − (chloride ion), N 3 − azide, F − (fluoride ion), NCO − (cyanate), (hydroxide), C 2 O 4 2− oxalate, H 2 O (water), NCS − (isothiocyanate), CH 3 CN (acetonitrile), C 5 H 5 N (pyridine), ethylenediamine (C 2 H 4 (NH 2 ) 2 ), bipy (2,2′-bipyridine), C 10 H 8 N 2 (phen (1,10-phenanthroline)), C 12 H 8 N 2 (phenanthroline), NO 2 − nitrite, P(C 6 H 5 ) 3 (triphenylphosphine), CN − (cyanide ion), and molecules in which C x H y O z where x, y, and z are integers and: at least x and y and z≧1, C x H y N z in which x, y, and z are integers and: at least x or y or z≧1, and N x O y where x and y are integers and: at least x or y≧1 wherein, the one or more layers of formed CEM comprise an atomic concentration of the molecular dopant approximately in the range of 0.1% to 10.0%.

2 . The method of claim 1 , wherein the substitutional ligand operates to reduce the concentration of defects in the coordination spheres forming the CEM, wherein the reduction in the concentration of defects in the coordination spheres inhibits conductive filament formation in the one or more layers of the CEM.

3 . The method of claim 1 , wherein the transition metal comprises nickel.

4 . The method of claim 1 , wherein the dominant ligand comprises oxygen, sulfur, selenium or tellurium, or a combination thereof.

5 . The method of claim 1 , wherein the substitutional ligand comprises carbonyl, ethylene, nitrosonium or ammonia, or any combination thereof.

6 . The method of claim 1 , wherein the one or more layers of CEM are formed on a conductive substrate.

7 . The method of claim 1 , wherein the substitutional ligand operates to reduce the concentration of defects in the coordination spheres forming the CEM, and wherein the reduction in the concentration of defects in the coordination spheres increases conductivity of the one or more layers of the CEM.

8 . The method of claim 7 , wherein the one or more layers of the CEM exhibits electron donation via a sigma bond between the transition metal and the molecular dopant, and wherein the CEM additionally exhibits electron back-donation utilizing a pi bond of the transition metal.

9 . A device, comprising:
a conductive substrate; and one or more layers of correlated electron material (CEM), formed on the substrate, the one or more layers of CEM formed from a transition metal or a transition metal oxide bonded with a dominant ligand, wherein the one or more layers of CEM comprise a substitutional ligand as a molecular dopant, wherein the molecular dopant comprises one or more of: O 2 2− (oxygen), I − (iodide ion), Br − (bromide ion), S 2− (sulfur), SCN − (thiocyanate ion, [SCN] − (sulfur-carbon-nitrogen ligand with carbon between), Cl − (chloride ion), N 3 − azide, (fluoride ion), NCO − (cyanate), (hydroxide), C 2 O 4 2− oxalate, H 2 O (water), NCS − (isothiocyanate), CH 3 CN (acetonitrile), C 5 H 5 N (pyridine), ethylenediamine (C 2 H 4 (NH 2 ) 2 ), bipy (2,2′-bipyridine), C 10 H 8 N 2 (phen (1,10-phenanthroline)), C 12 H 8 N 2 (phenanthroline), NO 2 − nitrite, P(C 6 H 5 ) 3 (triphenylphosphine), CN − (cyanide ion), and molecules in which C x H y O z where x, y, and z are integers and: at least x and y and z≧1, C x H y N z in which x, y, and z are integers and: at least x or y or z≧1, and N x O y where x and y are integers and: at least x or y≧1.

10 . The device of claim 9 , wherein the molecular dopant operates to inhibit formation of conductive filaments in the one or more layers of transition metal oxide film under an applied voltage.

11 . The device of claim 10 , wherein the one or more layers of CEM exhibit electron donation comprising donation of one or more electrons via a sigma bond between the transition metal and the substitutional ligand.

12 . The device of claim 11 , wherein the one or more layers of CEM exhibit electron back-donation to occur via a pi bond of the transition metal or transition metal oxide.

13 . The device of claim 9 , wherein the transition metal comprises nickel.

14 . The device of claim 9 , wherein the dominant ligand comprises oxygen, sulfur, selenium or tellurium, or a combination thereof.

15 . The device of claim 9 , wherein the substitutional ligand comprises carbonyl, ethylene, nitrosonium or ammonia, or any combination thereof.

16 . A switching device, comprising:
one or more layers of correlated electron material (CEM), formed on a substrate, the one or more layers of CEM formed from a transition metal or a transition metal oxide bonded with a dominant ligand, wherein the one or more layers of CEM comprise a substitutional ligand as a p-type molecular dopant to enable the CEM to change between impedance states at least partially in response to a voltage applied across the switching device, wherein the molecular dopant comprises one or more of: O 2 2− (oxygen), I − (iodide ion), Br − (bromide ion), S 2− (sulfur), SCN − (thiocyanate ion, [SCN] − (sulfur-carbon-nitrogen ligand with carbon between), Cl − (chloride ion), N 3 − azide, F − (fluoride ion), NCO − (cyanate), (hydroxide), C 2 O 4 2− oxalate, H 2 O (water), NCS − (isothiocyanate), CH 3 CN (acetonitrile), C 5 H 5 N (pyridine), ethylenediamine (C 2 H 4 (NH 2 ) 2 ), bipy (2,2′-bipyridine), C 10 H 8 N 2 (phen (1,10-phenanthroline)), C 12 H 8 N 2 (phenanthroline), NO 2 − nitrite, P(C 6 H 5 ) 3 (triphenylphosphine), CN − (cyanide ion), and molecules in which C x H y O z where x, y, and z are integers and: at least x and y and z≧1, C x H y N z in which x, y, and z are integers and: at least x or y or z≧1, and N x O y where x and y are integers and: at least x or y≧1.

17 . The switching device of claim 16 , wherein electron donation comprises donation via a sigma bond between transition metal and the substitutional ligand.

18 . The switching device of claim 17 , wherein the switching device performs a switching function via electron back-donation via a pi bond of the transition metal or transition metal oxide.

19 . The switching device of claim 18 , wherein the substitutional ligand comprises carbonyl, ethylene, nitrosonium or ammonia, or any combination thereof.

20 . A method, comprising:
exposing a substrate, in a chamber, to a first precursor in a gaseous state, the first precursor comprising a transition metal oxide, a transition metal or a transition metal compound, or any combination thereof, and a first ligand; exposing the substrate to a second precursor in a gaseous state, the second precursor comprising an oxide so as to form a first layer of a film of correlated electron material; and repeating the exposing of the substrate to the first and second precursors so as to form additional layers of the film of correlated electron material, the film of correlated electronic material exhibiting a first impedance state a

Assignees

• Advanced Risc Mach Ltd

Inventors

• Paz De Araujo Carlos Alberto
• Celinska Jolanta Bozena
• Reid Kimberly Gay
• Shifren Lucian

Classifications

• G11C13/0011

  comprising conductive bridging RAM [CBRAM] or programming metallization cells [PMCs] · CPC title

• C23C16/45527

  characterized by the ALD cycle, e.g. different flows or temperatures during half-reactions, unusual pulsing sequence, use of precursor mixtures or auxiliary reactants or activations · CPC title

• G11C13/0007

  comprising metal oxide memory material, e.g. perovskites · CPC title

• G11C11/5678

  using amorphous/crystalline phase transition storage elements · CPC title

• C23C16/45529

  specially adapted for making a layer stack of alternating different compositions or gradient compositions · CPC title