# US 2019/0318776 A1 · Cell-specific reference generation and sensing > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0318776 A1 - Document ID: US20190318776A1 - Status: Published application - Kind: A1 - Application number: 16/387,159 - Filed: 2019-04-17 - Published: 2019-10-17 - Earliest claimed: 2016-03-16 - Assignees: Micron Technology, Inc. - Applicants: Micron Technology, Inc. - Inventors: Christopher John Kawamura; Scott James Derner - Web page: https://patentgrep.com/patent/US20190318776A1 ## CPC - G11C 11/2273: {Reading or sensing circuits or methods} - G11C 7/14: Dummy cell management; Sense reference voltage generators - G11C 11/221: {using ferroelectric capacitors} - G11C 11/2293: {Timing circuits or methods} - G11C: STATIC STORES (semiconductor memory devices H10B) ## Abstract Methods, systems, and devices for operating a ferroelectric memory cell or cells are described. A portion of charge of a memory cell may be captured and, for example, stored using a capacitor or intrinsic capacitance of the memory array that includes the memory cell. The memory cell may be recharged (e.g., re-written). The memory cell may then be read, and a voltage of the memory cell may be compared to a voltage resulting from the captured charge. A logic state of the memory cell may be determined based at least in part on the voltage comparison. ## Claims ### Claim 1 (canceled) ### Claim 2 A method comprising: capturing, using a first digit line of a first ferroelectric memory cell, a first voltage from the first ferroelectric memory cell; storing a second voltage using a capacitor of the first ferroelectric memory cell, wherein the second voltage is a function of the first voltage; comparing the first voltage with the second voltage; and determining a logic state of the first ferroelectric memory cell based at least in part on the comparing the first voltage with the second voltage. ### Claim 3 (depends on 2) The method of claim 2, wherein the second voltage comprises a reference voltage and determining the logic state of the first ferroelectric memory cell comprises: determining the logic state based at least in part on a comparison of a value of the first voltage to the reference voltage. ### Claim 4 (depends on 2) The method of claim 2, wherein capturing the first voltage comprises: storing the first voltage on a digit line of a second ferroelectric memory cell. ### Claim 5 (depends on 2) The method of claim 2, wherein the logic state corresponds to a logic 1 or a logic 0 and a second state associated with the second voltage corresponds to an intermediary state between the logic 1 and the logic 0. ### Claim 6 (depends on 2) The method of claim 2, wherein the first voltage is based at least in part on a portion of a first charge stored in the first ferroelectric memory cell and the second voltage is based at least in part on a second charge related to the portion of the first charge. ### Claim 7 (depends on 6) The method of claim 6, further comprising: discharging a ferroelectric capacitor of the first ferroelectric memory cell onto a first digit line corresponding to the first ferroelectric memory cell and a second digit line, wherein the first voltage is based at least in part on charge-sharing between the first digit line and the second digit line. ### Claim 8 A method comprising: transferring a first voltage from a ferroelectric capacitor of a first ferroelectric memory cell to a digit line of a second ferroelectric memory cell; transferring a second voltage from the ferroelectric capacitor of the first ferroelectric memory cell to a digit line of the first ferroelectric memory cell; and comparing the first voltage on the digit line of the second ferroelectric memory cell to the second voltage on the digit line of the first ferroelectric memory cell. ### Claim 9 (depends on 8) The method of claim 8, further comprising: determining a logic state stored by the first ferroelectric memory cell, wherein the determining the logic state is based at least in part on comparing the first voltage to the second voltage. ### Claim 10 (depends on 8) The method of claim 8, wherein comparing comprises: using the second voltage as a reference voltage. ### Claim 11 (depends on 8) The method of claim 8, further comprising: reducing a voltage applied to the ferroelectric capacitor of the first ferroelectric memory cell to a threshold value based at least in part on transferring the first voltage. ### Claim 12 (depends on 11) The method of claim 11, further comprising: storing an intermediary state at the ferroelectric capacitor of the first ferroelectric memory cell based at least in part on the reduced voltage, wherein the intermediary state corresponds to the second voltage. ### Claim 13 (depends on 12) The method of claim 12, wherein the first voltage is based at least in part on a portion of a first charge of the ferroelectric capacitor of the first ferroelectric memory cell and the second voltage is based at least in part on the second charge. ### Claim 14 (depends on 8) The method of claim 8, wherein transferring the second voltage comprises: applying a voltage to the ferroelectric capacitor of the first ferroelectric memory cell. ### Claim 15 (depends on 13) The method of claim 13, further comprising: selecting the voltage applied to the ferroelectric capacitor based at least in part on the first voltage of the digit line of the second ferroelectric memory cell. ### Claim 16 (depends on 13) The method of claim 13, wherein a value of the second voltage is based at least in part on the voltage applied to the ferroelectric capacitor. ### Claim 17 (depends on 8) The method of claim 8, further comprising: activating a switching component in electronic communication with the digit line of the first ferroelectric memory cell and the digit line of the second ferroelectric memory cell, wherein transferring the first voltage is based at least in part on activating the switching component. ### Claim 18 A method comprising: capturing, using a first digit line of a first ferroelectric memory cell, a first voltage from the first ferroelectric memory cell; transferring the first voltage from the first digit line of the first ferroelectric memory cell to a second digit line of a second ferroelectric memory cell; storing the first voltage on the second digit line of the second ferroelectric memory cell; storing a second voltage using a capacitor of the first ferroelectric memory cell, wherein the second voltage is a function of the first voltage; comparing the first voltage with the second voltage; and determining a logic state of the first ferroelectric memory cell based at least in part on comparing the first voltage with the second voltage. ### Claim 19 (depends on 18) The method of claim 18, wherein the second voltage comprises a reference voltage and determining the logic state of the first ferroelectric memory cell comprises: determining the logic state based at least in part on a comparison of the first voltage with the reference voltage. ### Claim 20 (depends on 18) The method of claim 18, wherein capturing the first voltage comprises: storing the first voltage on a digit line of the second ferroelectric memory cell. ### Claim 21 (depends on 18) The method of claim 18, wherein the first voltage is based at least in part on a portion of a first charge stored in the first ferroelectric memory cell and the second voltage is based at least in part on a second charge related to the portion of the first charge.