# US 10,312,441 B1 · Tunable resistive element > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,312,441 B1 - Document ID: US10312441B1 - Status: Granted - Kind: B1 - Application number: 15/948,043 - Filed: 2018-04-09 - Granted: 2019-06-04 - Earliest claimed: 2018-04-09 - Assignees: International Business Machines Corporation - Applicants: International Business Machines Corporation - Inventors: Jean Fompeyrine; Stefan Abel; Veeresh Vidyadhar Deshpande - Web page: https://patentgrep.com/patent/US10312441B1 ## CPC - G11C 11/54: using elements simulating biological cells, e.g. neuron - H10N 70/883: {Oxides or nitrides} - G11C 13/0007: {comprising metal oxide memory material, e.g. perovskites} - G11C 13/0069: {Writing or programming circuits or methods} - G11C 13/0097: {Erasing, e.g. resetting, circuits or methods} - H10N 70/24: {based on migration or redistribution of ionic species, e.g. anions, vacancies} - H10N 70/801: {Constructional details of multistable switching devices} - H10N 70/826: {adapted for essentially vertical current flow, e.g. sandwich or pillar type devices} - H10N 70/8833: {Binary metal oxides, e.g. TaOx} - H10N 70/8836: {Complex metal oxides, e.g. perovskites, spinels} - G11C 2013/009: {Write using potential difference applied between cell electrodes} - G11C 2213/31: Material having complex metal oxide, e.g. perovskite structure - G11C 2213/32: Material having simple binary metal oxide structure - G11C 2213/50: Resistive cell structure aspects - G11C: STATIC STORES (semiconductor memory devices H10B) - H10N: ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR ## Abstract A tunable resistive element, comprising a first terminal, a second terminal, a dielectric layer and an intercalation layer. The dielectric layer and the intercalation layer are arranged in series between the first terminal and the second terminal. The dielectric layer is configured to form conductive filaments of oxygen vacancies on application of an electric field. The intercalation layer is configured to undergo a topotactic transition comprising an oxygen intercalation in combination with a change in the resistivity of the intercalation layer. A related memory device and a related neuromorphic network comprise resistive memory elements as memory cells and synapses respectively and a corresponding design structure. ## Claims ### Claim 1 A tunable resistive element, comprising a first terminal; a second terminal; a dielectric layer; and an intercalation layer, wherein the dielectric layer and the intercalation layer are arranged in series between the first terminal and the second terminal; the dielectric layer is configured to form conductive filaments of oxygen vacancies; and the intercalation layer is configured to undergo a topotactic transition comprising an oxygen intercalation in combination with a change in the resistivity of the intercalation layer. ### Claim 2 (depends on 1) A tunable resistive element according to claim 1, wherein the intercalation layer is configured to provide a decreasing resistance with an increasing oxygen level. ### Claim 3 (depends on 1) A tunable resistive element according to claim 1, wherein the tunable resistive element is configured to provide a first resistance state on application of one or electrical reset-pulses to the resistive element, the first resistance state being characterized by a low oxygen level in the intercalation layer and a fully oxidized dielectric layer; and provide a second resistance state on application of one or more set-pulses, the second resistance state being characterized by a plurality of oxygen paths in the intercalation layer between the dielectric layer and the first or the second terminal; and by conductive filaments of oxygen vacancies in the dielectric layer. ### Claim 4 (depends on 1) A tunable resistive element according to claim 1, wherein the tunable resistive element is configured to provide one or more intermediate resistance states on application of one or more set-pulses and/or reset pulses, the intermediate resistance states being characterized by conductive filaments of oxygen vacancies in the dielectric layer; and a plurality of oxygen regions extending from the conductive filaments in the intercalation layer towards the first or the second terminal. ### Claim 5 (depends on 1) A tunable resistive element according to claim 1, wherein the dielectric layer comprises conductive filaments being preformed in a fabrication process. ### Claim 6 (depends on 3) A tunable resistive element according to claim 3, wherein the intercalation layer is configured such that a difference in free energy levels between the intercalated and not-intercalated layer in the first resistance state and the second resistance state is below 1eV. ### Claim 7 (depends on 1) A tunable resistive element according to claim 1, wherein the intercalation layer comprises a perovskite or derivatives thereof. ### Claim 8 (depends on 1) A tunable resistive element according to claim 1, wherein the intercalation layer comprises a material selected from the group consisting of: SrCoO3-x, SrFrO3-x, SrMnO3-x, CaCrO3-x, BaInO3-x, SrTiO3-x, (with 0.5<×<1) and La2NiO4+x, La2CuO4+x with (0<×<0.3). ### Claim 9 (depends on 1) A tunable resistive element as claimed in claim 1, wherein the dielectric layer comprises a metal-oxide material. ### Claim 10 (depends on 9) A tunable resistive element as claimed in claim 9, wherein the metal oxide material is selected from the group consisting of: TiO2, HfO2, CeO2 and RE2O3, wherein RE is a rare earth material. ### Claim 11 (depends on 1) A tunable resistive element as claimed in claim 1, wherein the first terminal and/or the second terminal comprises a metal or metal-oxide. ### Claim 12 (depends on 11) A tunable resistive element as claimed in claim 11, wherein the metal or metal-oxide is selected from the group consisting of Ti, TiN, TaN, W, WO3, RuO2 and ITO. ### Claim 13 (depends on 1) A tunable resistive element as claimed in claim 1, wherein the dielectric layer has a thickness between 5 nm and 50 nm. ### Claim 14 (depends on 1) A tunable resistive element as claimed in claim 1, wherein the intercalation layer has a thickness between 5 nm and 50 nm. ### Claim 15 (depends on 3) A tunable resistive element as claimed in claim 3, wherein the resistive element is configured to provide a bidirectional resistance curve on application of set-pulses and reset pulses. ### Claim 16 (depends on 1) A memory device comprising a plurality of tunable resistive elements according to claim 1, the memory device comprising a control unit for applying electrical set pulses and electrical reset pulses as electrical programming pulses to the first terminal and/or the second terminal. ### Claim 17 (depends on 16) A memory device as claimed in claim 16, wherein the control unit is configured to apply: in a write mode one or more write voltages to the first terminal and the second terminal for writing a resistance state; and in a read mode a read voltage to the first and the second terminal for reading the resistance state. ### Claim 18 (depends on 16) A memory device as claimed in claim 16, wherein the control unit is configured to: apply one or more electrical set pulses to the resistive elements in order to form the conductive filaments of oxygen vacancies in the dielectric layer and to form conductive oxygen paths between the conductive filaments and the first terminal or the second terminal in the intercalation layer, thereby decreasing the resistance of the resistive element; and apply one or more electrical reset pulses to the resistive elements in order to deform the conductive filaments and to transfer oxygen from the intercalation layer to the dielectric layer, thereby increasing the resistance of the resistive element. ### Claim 19 (depends on 1) A neuromorphic network comprising a plurality of resistive elements according to claim 1 as synapses.