# US 8,787,064 B2 · Programmable bipolar electronic device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,787,064 B2 - Document ID: US8787064B2 - Status: Granted - Kind: B2 - Application number: 13/130,805 - Filed: 2009-01-13 - Published: 2011-09-22 - Granted: 2014-07-22 - Earliest claimed: 2009-01-13 - Assignees: Hewlett-Packard Development Company, L.P. - Applicants: Theodore I. Kamins; R. Stanley Williams - Inventors: Theodore I. Kamins; R. Stanley Williams - Web page: https://patentgrep.com/patent/US8787064B2 ## CPC - G11C 13/0002: {using resistive RAM [RRAM] elements} - G11C 13/003: {Cell access} - H10B 69/00: Erasable-and-programmable ROM [EPROM] devices not provided for in groups H10B41/00 - H10B63/00, e.g. ultraviolet erasable-and-programmable ROM [UVEPROM] devices - H10N 70/24: {based on migration or redistribution of ionic species, e.g. anions, vacancies} - H10N 70/253: {having three or more electrodes, e.g. transistor-like devices} - H10N 70/821: {Device geometry} - 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: STATIC STORES (semiconductor memory devices H10B) - H10B: ELECTRONIC MEMORY DEVICES - H10N: ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR ## Abstract A configurable memristive device (300) for regulating an electrical signal includes a memristive matrix (350) containing a first dopant species; emitter (320), collector (310), and a base electrodes (330, 340) which are in contact with the memristive matrix (350); and a mobile dopant species contained within a central region (360) contiguous with the base electrodes (330, 340), the mobile dopant species moving within the memristive matrix (350) in response to a programming electrical field. A method of configuring and using a memristive device (300) includes: applying a programming electrical field across a memristive matrix (350) such that a mobile dopant species creates a central doped region (360) which bisects the memristive matrix (350); and applying a control voltage to the central doped region (360) to regulate current flow between an emitter electrode (320) and a collector electrode (310). ## Claims ### Claim 1 A method of configuring a configurable memristive device comprising: a memristive matrix, said memristive matrix containing a first dopant species; an emitter electrode, a collector electrode, a programming electrode and a base electrode, said electrodes being in electrical contact with said memristive matrix; and a mobile dopant species different from the first dopant species, said method comprising: applying a programming electrical field between a pair of said electrodes to move said mobile dopant species within said memristive matrix while applying a second electrical field between another pair of said electrodes to control a shape of a distribution of said mobile dopant species within said memristive matrix. ### Claim 2 (depends on 1) The method of claim 1, wherein said first dopant species is also a mobile dopant species, said first dopant species moving within said memristive matrix in response to a programming electrical field. ### Claim 3 (depends on 2) The method of claim 2, wherein an electrical signal is regulated by repositioning said first dopant species. ### Claim 4 (depends on 1) The method of claim 1 wherein a programming voltage is applied to said memristive matrix such that said central region containing said mobile dopant species extends across said memristive matrix and divides said memristive matrix into two portions. ### Claim 5 (depends on 4) The method of claim 4, wherein said electrical signal is modulated by applying a control voltage to said base electrode such that a depletion zone between said central region and a region doped by said first dopant species is varied. ### Claim 6 (depends on 5) The method of claim 5, wherein said control voltage does not substantially reposition said mobile dopants. ### Claim 7 (depends on 1) The method of claim 1, wherein said memristive matrix is titanium dioxide. ### Claim 8 (depends on 7) The method of claim 7, wherein said first dopant is one of: an n-type dopant and a p-type dopant; said n-type dopant comprises one of: oxygen vacancies and beryllium ions; said p-type dopant comprises one of: magnesium ions and calcium ions. ### Claim 9 (depends on 1) The method of claim 1, wherein said mobile dopant is one of: an n-type dopant and a p-type dopant; and said mobile dopant having an opposite charge from said first dopant. ### Claim 10 (depends on 1) The method of claim 1, further comprising a reservoir, said reservoir containing said mobile dopant prior to application of said programming voltage. ### Claim 11 (depends on 1) The method of claim 1, further comprising, after applying said programming electrical field to position said mobile dopant species between said emitter and collector electrodes, applying a control voltage to said base electrode to regulate current flow between said emitter electrode and said collector electrode. ### Claim 12 (depends on 1) The method of claim 1, further comprising: applying said programming electrical field between said base and programming electrodes; and applying said second electrical field between said emitter and collector electrodes. ### Claim 13 (depends on 1) The method of claim 1, wherein said second electrical field is applied orthogonally to said programming electrical field. ### Claim 14 A method of configuring a memristive device comprising: applying a programming electrical field across a memristive matrix, said memristive matrix being doped with a first dopant, said memristive matrix being in electrical contact with an emitter electrode, a collector electrode, a base electrode and a programming electrode; distributing a mobile dopant using said programming electrical field such that said mobile dopant forms a central doped region which divides into two portions said memristive matrix, wherein the mobile dopant is different from the first dopant; and applying a second electrical field with two of said four electrodes to control a size of said central doped region. ### Claim 15 (depends on 14) The method of claim 14, further comprising tuning transistor characteristics of said memristive device by adjusting a distribution of at least one of said first dopant and said mobile dopant. ### Claim 16 (depends on 14) The method of claim 14, further comprising withdrawing said central doped region by applying a programming electrical field which moves said mobile dopants to one side of said memristive matrix. ### Claim 17 (depends on 14) The method of claim 14, further comprising removing said programming electrical field after said mobile dopants form said central doped region (360) which divides said memristive matrix into two portions; said mobile dopants remaining positionally stable within said memristive matrix until another programming electrical field is applied. ### Claim 18 (depends on 14) The method of claim 14, further comprising applying a control voltage to said base electrode to regulate current flow between said emitter electrode and said collector electrode. ### Claim 19 (depends on 14) The method of claim 14, further comprising applying said programming electrical field between said base and programming electrodes; and applying said second electrical field between said emitter and collector electrodes. ### Claim 20 (depends on 14) The method of claim 14, wherein said second electrical field is applied orthogonally to said programming electrical field.