# US 10,374,155 B2 · Electrically actuated switch > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,374,155 B2 - Document ID: US10374155B2 - Status: Granted - Kind: B2 - Application number: 15/653,210 - Filed: 2017-07-18 - Published: 2017-11-02 - Granted: 2019-08-06 - Earliest claimed: 2006-10-03 - Assignees: Hewlett Packard Enterprise Development LP - Applicants: Hewlett Packard Enterprise Development LP - Inventors: R. Stanley Williams - Web page: https://patentgrep.com/patent/US10374155B2 ## CPC - H10N 70/24: {based on migration or redistribution of ionic species, e.g. anions, vacancies} - G11C 13/0007: {comprising metal oxide memory material, e.g. perovskites} - G11C 13/0009: {RRAM elements whose operation depends upon chemical change} - H03K 17/00: Electronic switching or gating, i.e. not by contact-making and –breaking (gated amplifiers H03F3/72; switching arrangements for exchange systems using static devices H04Q3/52) - H10B 63/80: {Arrangements comprising multiple bistable or multi-stable switching components of the same type on a plane parallel to the substrate, e.g. cross-point arrays} - H10N 70/253: {having three or more electrodes, e.g. transistor-like devices} - H10N 70/826: {adapted for essentially vertical current flow, e.g. sandwich or pillar type devices} - H10N 70/881: {Switching materials} - H10N 70/883: {Oxides or nitrides} - H10N 70/8833: {Binary metal oxides, e.g. TaOx} - H10N 70/8836: {Complex metal oxides, e.g. perovskites, spinels} - G11C 2213/52: Structure characterized by the electrode material, shape, etc. - G11C 2213/53: Structure wherein the resistive material being in a transistor, e.g. gate - G11C 2213/56: 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 - G11C 2213/77: Array wherein the memory element being directly connected to the bit lines and word lines without any access device being used - H10N: ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR - G11C: STATIC STORES (semiconductor memory devices H10B) - H03K: PULSE TECHNIQUE (measuring pulse characteristics G01R; modulating sinusoidal oscillations with pulses H03C; transmission of digital information H04L; discriminator circuits detecting phase difference between two signals by counting or integrating cycles of oscillation H03D3/04; automatic control, starting, synchronisation or stabilisation of generators of electronic oscillations or pulses where the type of generator is irrelevant or unspecified H03L; coding, decoding or code conversion, in general H03M) - H10B: ELECTRONIC MEMORY DEVICES ## Abstract An electrically actuated switch comprises a first electrode, a second electrode, and an active region disposed therebetween. The active region comprises at least one primary active region comprising at least one material that can be doped or undoped to change its electrical conductivity, and a secondary active region comprising at least one material for providing a source/sink of ionic species that act as dopants for the primary active region(s). Methods of operating the switch are also provided. ## Claims ### Claim 1 A method comprising: providing an electrically actuated switch that can be switched between a higher conductivity state (ON) and a lower conductivity state (OFF), the switch comprising a first electrode, a second electrode; and an active region disposed therebetween, the active region comprising a primary active region comprising at least one material for transporting and hosting ions that act as dopants to control the flow of electrons through the switch, and a secondary active region comprising at least one material for providing a source/sink of ionic dopants for the primary active region; and inverting an ON/OFF polarity of the switch from a first polarity to a second polarity by applying a positive bias to the second electrode for a long enough time to cause the ON/OFF polarity of the switch to change to the second polarity, the first polarity comprising a state in which applying a positive bias to the second electrode turns the switch ON and applying a negative bias to the second electrode turns the switch OFF, the second polarity comprising a state in which applying a negative bias to the second electrode turns the switch ON and applying a positive bias to the second electrode turns the switch OFF. ### Claim 2 (depends on 1) The method of claim 1, wherein, in inverting the ON/OFF polarity of the switch from the first polarity to the second polarity, applying the positive bias to the second electrode for a long enough time to cause the ON/OFF polarity of the switch to change to the second polarity includes applying the positive bias to the second electrode for a long enough time to cause all positive dopants to drift to the first electrode. ### Claim 3 (depends on 1) The method of claim 1, further comprising: inverting the ON/OFF polarity of the switch from the second polarity to the first polarity by applying a negative bias to the second electrode for a long enough time to cause the ON/OFF polarity of the switch to change to the first polarity. ### Claim 4 (depends on 3) The method of claim 3, wherein, in inverting the ON/OFF polarity of the switch from the second polarity to the first polarity, applying the negative bias to the second electrode for a long enough time to cause the ON/OFF polarity of the switch to change to the first polarity includes applying the negative bias to the second electrode for a long enough time to cause all positive dopants to drift to the second electrode. ### Claim 5 (depends on 1) The method of claim 1, wherein the primary active region includes a first primary active region and a second primary active region, each comprising at least one of the at least one materials for transporting and hosting ions that act as dopants to control the flow of electrons through the switch, and the secondary active region is disposed between the first and second primary active regions. ### Claim 6 (depends on 5) The method of claim 5, wherein the switch further comprise a non-covalent interface, disposed between the first electrode and the first primary active region. ### Claim 7 (depends on 6) The method of claim 6, further comprising: using the states of the switch to store a bit of information, including setting the switch in the first state to store a first logical value and setting the switch in the second state to store a second logical value. ### Claim 8 (depends on 5) The method of claim 5, wherein the switch is configurable into states including: a first state in which there is undoped semiconductor adjacent to both the first and second electrodes, resulting in two Schottky barriers that are in series and having opposite polarities, thereby effectively blocking current flow in both directions of the device, a second state in which dopants are injected into a region near the first electrode and the Schottky barrier adjacent to the first electrode is decreased, thereby allowing current to flow more readily in a first direction, and a third state in which dopants are injected to a region near the second electrode and the Schottky barrier adjacent to the second electrode is decreased, thereby allowing current to flow more readily in a second direction opposite the first direction. ### Claim 9 (depends on 5) The method of claim 5, wherein the ionic dopants provided by the secondary active region act as electrical dopants for the at least one material of the primary active region, and thereby change the electrical conductivity of the primary active region from a relatively low electrical conductivity to a relatively high conductivity. ### Claim 10 (depends on 5) The method of claim 5, wherein the ionic dopants provided by the secondary active region are selected from the group consisting of ionized interstitial or substitutional impurity atoms, cation donor species, anion vacancies, and anionic acceptor species. ### Claim 11 (depends on 5) The method of claim 5, wherein the ionic dopants provided by the secondary active region are selected from the group consisting of hydrogen, alkali and alkaline earth cations, transition metal cations, rare earth cations, oxygen anions or vacancies, chalcogenide anions or vacancies, nitrogen anions or vacancies, pnictide anions or vacancies, or halide anions or vacancies. ### Claim 12 (depends on 5) The method of claim 5, wherein the at least one material for the one primary active region and at least one material for the secondary active region are selected from the group consisting of: (1) oxides, sulfides, selenides, ni-trides, phosphides, arsenides, chlorides, and bromides of transition metals, rare earth metals, and alkaline earth metals; (2) alloys of like compounds from list (1) with each other; and (3) mixed compounds, in which there are at least two different metal atoms combined with at least one electronegative element. ### Claim 13 (depends on 5) The method of claim 5, wherein the at least one material for the primary active region and the at least one material for the secondary active region are selected from the group consisting of titanates, zirconates, haf-nates, alloys of these three oxides in pairs or with all three present together, and compounds of the type ABO3, where A is at least one divalent element and B is at least one of Ti, Zr, and Hf. ### Claim 14 (depends on 5) The method of claim 5, wherein the at least one material for the one primary active region and the at least one material for the secondary active region are selected from the following list: TiO2/TiO2-x; ZrO2/ZrO2-x; HfO2/HfO2-x; SrTiO3/SrTiO3-x; GaN/GaN1-x; CuCl/CuCl1-x; and GaN/GaN:S. ### Claim 15 A method comprising: providing an electrically actuated switch that can be switched between a higher conductivity state (ON) and a lower conductivity state (OFF), the switch comprising a first electrode, a second electrode; and an active region disposed therebetween, the active region comprising a first primary active region and a second primary active region, each comprising at least one material for transporting and hosting ions that act as dopants to control the flow of electrons through the switch, and a secondary active region disposed between the first and second primary active regions and comprising at least one material for providing a source/sink of ionic dopants for the first and second primary active regions; and inverting an ON/OFF polarity of the switch by: while the ON/OFF polarity of the switch is a first polarity, in which applying a positive bias to the second electrode turns the switch ON and applying a negative bias to the second electrode turns the switch OFF, applying a positive bias to the second electrode for a long enough time to cause the ON/OFF polarity of the switch to change to a second polarity, in which applying a negative bias to the second electrode turns the switch ON and applying a positive bias to the second electrode turns the switch OFF; and while the ON/OFF polarity of the switch is the second polarity, applying a negative bias to the second electrode for a long enough time to cause the ON/OFF polarity of the switch to change to the first polarity. ### Claim 16 A method comprising: providing an electrically actuated switch that can be switched between a higher conductivity state (ON) and a lower conductivity state (OFF), the switch comprising a first electrode, a second electrode; and an active region disposed therebetween, the active region comprising a first primary active region and a second primary active region, each comprising at least one material for transporting and hosting ions that act as dopants to control the flow of electrons through the switch, and a secondary active region disposed between the first and second primary active regions and comprising at least one material for providing a source/sink of ionic dopants for the first and second primary active regions; and inverting an ON/OFF polarity of the switch by: in a first state in which applying a positive bias to the second electrode turns ON the switch and applying a negative bias to the second electrode turns OFF the switch, applying a positive bias to the second electrode for a long enough time to cause the switch to change to a second state in which applying a positive bias to the first electrode turns ON the switch and applying a positive bias to the first electrode turns the switch OFF; and in the second state, applying a negative bias to the second electrode for a long enough time to cause the switch to change to the first state.