Patent application number | Description | Published |
20100014343 | NONVOLATILE MEMORY APPARATUS AND NONVOLATILE DATA STORAGE MEDIUM - [Objective] A nonvolatile memory apparatus and a nonvolatile data storage medium of the present invention, including nonvolatile memory elements each of which changes its resistance in response to electric pulses applied, comprises a first write circuit ( | 01-21-2010 |
20100103723 | NONVOLATILE MEMORY APPARATUS - Provided are a plurality of memory cell arrays | 04-29-2010 |
20110007553 | NONVOLATILE STORAGE DEVICE AND METHOD FOR WRITING INTO MEMORY CELL OF THE SAME - Provided is a nonvolatile storage device ( | 01-13-2011 |
20110110144 | WRITING METHOD FOR VARIABLE RESISTANCE NONVOLATILE MEMORY ELEMENT, AND VARIABLE RESISTANCE NONVOLATILE MEMORY DEVICE - A writing method optimum for a variable resistance element which can maximize an operation window of the variable resistance element is provided. The writing method is performed for a variable resistance element that reversibly changes between a high resistance state and a low resistance state depending on a polarity of an applied voltage pulse. The writing method includes a preparation step (S | 05-12-2011 |
20110128773 | NONVOLATILE VARIABLE RESISTANCE MEMORY ELEMENT WRITING METHOD, AND NONVOLATILE VARIABLE RESISTANCE MEMORY DEVICE - To provide a variable resistance element writing method that, even when a variable resistance element has a possibility of becoming a half LR state, can ensure a maximum resistance change window by correcting the variable resistance element to a normal low resistance state. In a method of writing data to a variable resistance element ( | 06-02-2011 |
20110216577 | VARIABLE RESISTANCE NONVOLATILE STORAGE DEVICE - The variable resistance nonvolatile storage device reduces variations in a resistance value of a variable resistance element ( | 09-08-2011 |
20120120712 | FORMING METHOD FOR VARIABLE RESISTANCE NONVOLATILE MEMORY ELEMENT, AND VARIABLE RESISTANCE NONVOLATILE MEMORY DEVICE - An optimum forming method of performing a forming for a variable resistance element to maximize an operation window of the variable resistance element is provided. The forming method is used to initialize a variable resistance element ( | 05-17-2012 |
20120230085 | FORMING METHOD OF PERFORMING FORMING ON VARIABLE RESISTANCE NONVOLATILE MEMORY ELEMENT, AND VARIABLE RESISTANCE NONVOLATILE MEMORY DEVICE - In forming, an automatic forming circuit ( | 09-13-2012 |
20130003439 | NONVOLATILE VARIABLE RESISTANCE MEMORY ELEMENT WRITING METHOD, AND NONVOLATILE VARIABLE RESISTANCE MEMORY DEVICE - A method of writing data to a variable resistance element ( | 01-03-2013 |
20130044534 | FORMING METHOD OF PERFORMING FORMING ON VARIABLE RESISTANCE NONVOLATILE MEMORY ELEMENT, AND VARIABLE RESISTANCE NONVOLATILE MEMORY DEVICE - A forming method of a variable resistance nonvolatile memory element capable of lowering a forming voltage and preventing variations of the forming voltage depending on variable resistance elements. The forming method is for initializing a variable resistance element, including a step (S | 02-21-2013 |
20130114327 | VARIABLE RESISTANCE NONVOLATILE MEMORY DEVICE - A variable resistance nonvolatile memory device including memory cells provided at cross-points of first signal lines and second signal lines, each memory cell including a variable resistance element and a current steering element connected to the variable resistance element in series, the variable resistance nonvolatile memory device including a write circuit, a row selection circuit, and a column selection circuit, wherein the write circuit: sequentially selects blocks in an order starting from a block farthest from at least one of the row selection circuit and the column selection circuit and finishing with a block closest to the at least one of the row selection circuit and the column selection circuit; and performs, for each of the selected blocks, initial breakdown on each memory cell included in the selected block. | 05-09-2013 |
20130148408 | METHOD OF PROGRAMMING VARIABLE RESISTANCE NONVOLATILE MEMORY ELEMENT - A method of programming a variable resistance nonvolatile memory element that removes a defect in a resistance change, ensures an operation widow, and stably sustains a resistance change operation, the method including: applying, when the detect in the resistance change occurs in the variable resistance nonvolatile memory element, a recovery voltage pulse at least once to the variable resistance nonvolatile memory element, the recovery voltage pulse including: a first recovery voltage pulse that has an amplitude greater than amplitudes of a normal high resistance writing voltage pulse and a low resistance writing voltage pulse; and a second recovery voltage pulse that is the low resistance writing voltage pulse following the first recovery voltage pulse. | 06-13-2013 |
20130188414 | VARIABLE RESISTANCE NONVOLATILE MEMORY ELEMENT WRITING METHOD AND VARIABLE RESISTANCE NONVOLATILE MEMORY DEVICE - A variable resistance nonvolatile memory element writing method of, by applying a voltage pulse to a memory cell including a variable resistance element, reversibly changing the variable resistance element between a first resistance state and a second resistance state according to a polarity of the applied voltage pulse is provided. The variable resistance nonvolatile memory element writing method includes applying a first preliminary voltage pulse and subsequently applying the first voltage pulse to the variable resistance element to change the variable resistance element from the second resistance state to the first resistance state, the first preliminary voltage pulse being smaller in voltage absolute value than the second threshold voltage and different in polarity from the first voltage pulse. | 07-25-2013 |
20140078811 | VARIABLE RESISTANCE NONVOLATILE MEMORY ELEMENT WRITING METHOD AND VARIABLE RESISTANCE NONVOLATILE MEMORY DEVICE - Provided is a method of writing to a variable resistance nonvolatile memory element which is capable of both improving retention characteristics and enlarging a window of operation. In the method of writing, to write “1” data (LR), first a weak HR writing process is performed in which a weak HR writing voltage pulse set for changing the variable resistance nonvolatile memory element to an intermediate resistance state is applied and, subsequently, a LR writing process is performed in which a LR writing voltage pulse set for changing the variable resistance nonvolatile memory element from the intermediate resistance state to a LR state is applied. | 03-20-2014 |
20140112054 | CROSSPOINT NONVOLATILE MEMORY DEVICE AND FORMING METHOD THEREOF - A sense amplification circuit includes a sneak current compensating load current supply unit that selectively switches a load current among load currents having different current amounts and supplies the load current to a bit line selected by a column selection circuit. The sense amplification circuit outputs ‘L’ level when a current amount of the load current is more than a reference current amount, and outputs ‘H’ level when the current amount is less than the reference current amount. A control circuit adjusts the current amount to a predetermined current amount that causes the sense amplification circuit to output ‘H’ level. After the adjustment, the control circuit performs control to supply the load current having the predetermined current amount and controls the writing unit to keep the application until the sense amplification circuit outputs ‘L’ level. | 04-24-2014 |
20140185360 | WRITE METHOD FOR WRITING TO VARIABLE RESISTANCE NONVOLATILE MEMORY ELEMENT AND VARIABLE RESISTANCE NONVOLATILE MEMORY DEVICE - A write method for writing to a variable resistance nonvolatile memory element, comprising applying a set of strong recovery-voltage pulses at least once to the variable resistance nonvolatile memory element when it is determined that the resistance state of the variable resistance nonvolatile memory element fails to change to a second resistance state, remaining in a first resistance state, the set of strong recovery-voltage pulses including pulses: (1) a first strong recovery-voltage pulse which has a greater amplitude than a normal second voltage for changing the resistance state to the first resistance state, and has the same polarity as the second voltage; and (2) a second strong recovery-voltage pulse which follows the first strong recovery-voltage pulse and has a longer pulse width than the pulse width of the normal first voltage for changing the resistance state to the second resistance state, and has the same polarity as the first voltage. | 07-03-2014 |
20140301129 | WRITING METHOD OF VARIABLE RESISTANCE NON-VOLATILE MEMORY ELEMENT AND VARIABLE RESISTANCE NON-VOLATILE MEMORY DEVICE - A writing method of a variable resistance non-volatile memory element comprises determining, in a first determination step, whether or not a resistance state of the variable resistance non-volatile memory element does not switch to a first resistance state and remains in a second resistance state, when a pulse of a second voltage is applied to the variable resistance non-volatile memory element; and when it is determined that the resistance state of the variable resistance non-volatile memory element does not switch to the first resistance state and remains in the second resistance state in the first determination step, applying, in a recovery step, at least once to the variable-resistance non-volatile memory element a recovery voltage pulse set composed of two pulses which are a first recovery voltage pulse which has the same polarity as that of the first voltage and a second recovery voltage pulse which has the same polarity as that of the second voltage, has a greater amplitude than the second voltage, and is applied subsequently to the first recovery voltage pulse. | 10-09-2014 |
20140321196 | VARIABLE RESISTANCE NONVOLATILE MEMORY DEVICE AND METHOD FOR WRITING INTO THE SAME - In a method for writing into a variable resistance nonvolatile memory device according to one aspect of the present disclosure, a verify write operation of newly applying a voltage pulse for changing a resistance state is performed on a variable resistance element which does not satisfy a determination condition for verifying that the resistance state has been changed despite application of a voltage pulse for changing the resistance state, and the determination condition in the verify write operation is relaxed when an average number of times of verify write operation, having already been performed on all or part of a plurality of variable resistance elements that are targets for write operation, exceeds a predetermined number of times. | 10-30-2014 |