# US 2022/0044728 A1 · Cross-Point Array of Polymer Junctions with Individually-Programmed Conductances > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2022/0044728 A1 - Document ID: US20220044728A1 - Status: Published application - Kind: A1 - Application number: 17/509,941 - Filed: 2021-10-25 - Published: 2022-02-10 - Earliest claimed: 2019-07-18 - Assignees: International Business Machines Corporation - Applicants: International Business Machines Corporation - Inventors: Ali Afzali-Ardakani; James B. Hannon - Web page: https://patentgrep.com/patent/US20220044728A1 ## CPC - G11C 13/0064: {Verifying circuits or methods} - G11C 13/0016: {comprising polymers} - G11C 13/003: {Cell access} - G11C 13/004: {Reading or sensing circuits or methods} - G11C 13/0069: {Writing or programming circuits or methods} - H10K 10/50: Bistable switching devices - H10K 19/202: {Integrated devices comprising a common active layer} - H10K 71/211: {by selective transformation of an existing layer} - G11C 2013/0066: {Verify correct writing whilst writing is in progress, e.g. by detecting onset or cessation of current flow in cell and using the detector output to terminate writing} - G11C 2213/77: Array wherein the memory element being directly connected to the bit lines and word lines without any access device being used - H10K 85/111: {comprising aromatic, heteroaromatic, or aryl chains, e.g. polyaniline, polyphenylene or polyphenylene vinylene} - H10K 85/60: Organic compounds having low molecular weight (H10K85/10 - H10K85/50 take precedence) - G11C: STATIC STORES (semiconductor memory devices H10B) - H10K: ORGANIC ELECTRIC SOLID-STATE DEVICES ## Abstract Programmable memory devices having a cross-point array of polymer junctions with individually-programmed conductances are provided. In one aspect, a method of forming a memory device includes: forming first metal lines on an insulating substrate; forming polymeric resistance elements on the first metal lines; and forming second metal lines over the polymeric resistance elements with a single one of the polymeric resistance elements present at each intersection of the first/second metal lines forming a cross-point array. A memory device and a method of operating a memory device are also provided. ## Claims ### Claim 1 A method of operating a memory device, the method comprising: providing the memory device comprising: first metal lines disposed on an insulating substrate; polymeric resistance elements disposed on the first metal lines, wherein the polymeric resistance elements comprise an organic polymer that is electrically conductive; second metal lines disposed over the polymeric resistance elements; and programming the polymeric resistance elements using a voltage bias to increase a resistance of the polymeric resistance elements. ### Claim 2 (depends on 1) The method of claim 1, further comprising: reading out a resistance value of the polymeric resistance elements. ### Claim 3 (depends on 1) The method of claim 1, wherein the first metal lines form a series of rows and the second metal lines form a series of columns, and wherein the programming of the polymeric resistance elements further comprises: applying the voltage bias via the rows and the columns to increase the resistance of the polymeric resistance elements. ### Claim 4 (depends on 3) The method of claim 3, wherein the voltage bias used to program the polymeric resistance elements is greater than a threshold, and wherein the method further comprises: applying the voltage bias to a given one of the rows, row i, while grounding a given one of the columns, column j, to program a given one of the polymeric resistance elements, polymeric resistance element ij; monitoring current in the column j as a measure of conductance of the polymeric resistance element ij; lowering the voltage bias below the threshold when the current in the column j reaches a value corresponding to a desired resistance value Rij for the polymeric resistance element ij; and repeating the applying, monitoring and lowering steps to program another one of the polymeric resistance elements. ### Claim 5 (depends on 3) The method of claim 3, wherein the voltage bias used to program the polymeric resistance elements is greater than a threshold, and wherein the method further comprises: applying the voltage bias to a given one of the rows, row i, while grounding each of the columns to program the polymeric resistance elements in the row i; monitoring current in each of the columns as a measure of conductance of the polymeric resistance elements in the row i; lowering the voltage bias below the threshold when the current in each of the columns reaches a value corresponding to a desired resistance value Rij for the polymeric resistance elements in the row i; and repeating the applying, monitoring and lowering steps to program the polymeric resistance elements in another one of the rows. ### Claim 6 (depends on 3) The method of claim 3, wherein the voltage bias is applied continuously. ### Claim 7 (depends on 3) The method of claim 3, wherein the voltage bias is applied as a sequence of voltage pulses. ### Claim 8 (depends on 1) The method of claim 1, wherein the organic polymer comprises polyaniline. ### Claim 9 (depends on 1) The method of claim 1, wherein the organic polymer is doped with an acid. ### Claim 10 (depends on 9) The method of claim 9, wherein the acid comprises trifluoromethane sulfonylimide. ### Claim 11 (depends on 1) The method of claim 1, wherein the memory device further comprises: a layer of the organic polymer disposed on the insulating substrate over the first metal lines, wherein the layer of the organic polymer comprises: first regions which are electrically conductive and correspond to the polymeric resistance elements, and second regions which are electrically insulating. ### Claim 12 (depends on 11) The method of claim 11, further comprising: an electrically conductive mask on the layer of the organic polymer that covers the first regions. ### Claim 13 (depends on 12) The method of claim 12, wherein the electrically conductive mask comprises a metal selected from the group consisting of: copper (Cu), gold (Au), nickel (Ni), platinum (Pt), palladium (Pd), cobalt (Co) and combinations thereof and combinations thereof. ### Claim 14 (depends on 12) The method of claim 12, wherein the second metal lines are disposed over the electrically conductive mask, and wherein the second metal lines are conformal over, and in direct contact with, the electrically conductive mask such that the second metal lines have a raised topography wherever the second metal lines pass over the electrically conductive mask. ### Claim 15 A method of operating a memory device, the method comprising: providing the memory device comprising: first metal lines disposed on an insulating substrate; polymeric resistance elements disposed on the first metal lines, wherein the polymeric resistance elements comprise an organic polymer that is electrically conductive; second metal lines disposed over the polymeric resistance elements, wherein a single one of the polymeric resistance elements is present at each intersection of the first metal lines and the second metal lines forming a cross-point array with the first metal lines forming a series of rows and the second metal lines forming a series of columns; and programming the polymeric resistance elements using a voltage bias applied via the rows and the columns to increase a resistance of the polymeric resistance elements. ### Claim 16 (depends on 15) The method of claim 15, further comprising: reading out a resistance value of the polymeric resistance elements ### Claim 17 (depends on 15) The method of claim 15, wherein the voltage bias used to program the polymeric resistance elements is greater than a threshold, and wherein the method further comprises: applying the voltage bias to a given one of the rows, row i, while grounding a given one of the columns, column j, to program a given one of the polymeric resistance elements, polymeric resistance element ij; monitoring current in the column j as a measure of conductance of the polymeric resistance element ij; lowering the voltage bias below the threshold when the current in the column j reaches a value corresponding to a desired resistance value Rij for the polymeric resistance element ij; and repeating the applying, monitoring and lowering steps to program another one of the polymeric resistance elements. ### Claim 18 (depends on 15) The method of claim 15, wherein the voltage bias used to program the polymeric resistance elements is greater than a threshold, and wherein the method further comprises: applying the voltage bias to a given one of the rows, row i, while grounding each of the columns to program the polymeric resistance elements in the row i; monitoring current in each of the columns as a measure of conductance of the polymeric resistance elements in the row i; lowering the voltage bias below the threshold when the current in each of the columns reaches a value corresponding to a desired resistance value Rij for the polymeric resistance elements in the row i; and repeating the applying, monitoring and lowering steps to program the polymeric resistance elements in another one of the rows. ### Claim 19 (depends on 15) The method of claim 15, wherein the voltage bias is applied continuously. ### Claim 20 (depends on 15) The method of claim 15, wherein the voltage bias is applied as a sequence of voltage pulses.