Adesto Technologies Corporation

Axon Technologies Corporation

Other

Deepak Kamalanathan

Venkatesh P Gopinath

Juan Pablo Saenz Echeverry

Foroozan Sarah Koushan

John Dinh

Shane Charles Hollmer

Michael N Kozicki

Ming Sang Kwan

Derric Lewis

Daniel Wang

John Ross Jameson

David Kim

Janet Wang

Nathan Gonzales

In one embodiment, a method of operating a resistive switching device includes applying a signal comprising a pulse on a first terminal of a two terminal resistive switching device having the first terminal and a second terminal. The resistive switching device has a first state and a second state. The pulse includes a first ramp from a first voltage to a second voltage over a first time period. The first time period is at least 0.1 times a total time period of the pulse.

Resistive memory device with ramp-up/ramp-down program/erase pulse

A method can include applying a first electric field to a plurality of memory elements that are programmable between at least two different resistance states; verifying whether the memory elements have a resistance outside of a first limit; for memory elements that are not outside of the first limit, applying a second electric field of a same direction as the first electric field, and not applying the second electric field to those memory elements that are outside the first limit; and verifying whether the memory elements receiving the second electric field have a resistance outside of a second limit; wherein the second limit is between the first limit and a read limit, where a memory element having a resistance below the read limit is determined to store one data value, and a memory element having a resistance above the read limit is determined to store another data value.

Methods for setting a resistance of programmable resistance memory cells and devices including the same

In one embodiment, a semiconductor memory device includes a plurality of resistive switching memory cells, where each resistive switching memory cell can include: (i) a programmable impedance element having an anode and a cathode; (ii) an access transistor having a drain coupled to a bit line, a source coupled to the programmable impedance element cathode, and a gate coupled to a word line; (iii) a well having a first diffusion region configured as the source, a second diffusion region configured as the drain, and a third diffusion region configured as a well contact; and (iv) a diode having a cathode at the second diffusion region, and an anode at the third diffusion region, where the diode is turned on during an erase operation on the programmable impedance element.

Resistive switching memory having a resistor, diode, and switch memory cell

A method of controlling a resistive switching memory cell can include: receiving a first command to be executed on the resistive switching memory cell; performing, in response to the first command, an erase operation to erase the resistive switching memory cell to an erased state; verifying the erased state of the resistive switching memory cell; performing a weak program operation to program the resistive switching memory cell to a first programmed state; and verifying the first programmed state of the resistive switching memory cell.

Dual program state cycling algorithms for resistive switching memory device

In one embodiment, a semiconductor memory device includes a plurality of resistive switching memory cells, where each resistive switching memory cell can include: (i) a programmable impedance element having an anode and a cathode; (ii) a word line pair configured to control access to the programmable impedance element, where the word line pair comprises first and second word lines; (iii) a PMOS transistor having a source coupled to the cathode, a drain coupled to a bit line, and a gate coupled to the first word line; and (iv) an NMOS transistor having a source coupled to the bit line, a drain coupled to the cathode, and a gate coupled to the second word line.

Resistive switching memory with cell access by analog signal controlled transmission gate

In accordance with an embodiment of the present invention, a memory cell includes a two terminal access device disposed above a semiconductor substrate. The access device includes a two terminal resistive switching device having substantially zero retention. The two terminal resistive switching device has a low resistance state and a high resistance state. A memory device is disposed above the semiconductor substrate. The memory device is coupled to the access device.

Two terminal resistive access devices and methods of formation thereof

A memory device can include a plurality of two terminal conductive bridging random access memory (CBRAM) type memory elements; at least one program transistor configured to enable a program current to flow through at least one memory element in response to the application of a program signal at its control terminal and a program bias voltage to the memory element; and an erase load circuit that includes at least one two-terminal diode-like load element, the erase load circuit configured to enable an erase current to flow through the load element and at least one memory element in a direction opposite to that of the program current.

Circuits and methods for placing programmable impedance memory elements in high impedance states

Method of operating a resistive memory device with a ramp-up/ramp-down program/erase pulse

A memory cell includes a first resistive switching device having a first terminal and a second terminal, a switching device having a first terminal and a second terminal, and an access device having a first access terminal and a second access terminal. The first access terminal is coupled to the first terminal of the first resistive switching device and the first terminal of the switching device.

Resistive switching memories

A memory device can include a plurality of programmable impedance elements programmable between a low impedance state in response to a program voltage and a higher impedance state in response to an erase voltage having a different polarity than the program voltage; a programming circuit configured to apply the program and erase voltages to selected elements; and a pre-condition path configured to apply a pre-condition voltage only of the erase voltage polarity to fresh elements in a pre-condition operation; wherein fresh elements are elements that have not been subject to any programming voltages. The pre-condition electrical conditions can also include high voltage low current conditions that apply a greater magnitude voltage and smaller current than the first or second electrical conditions, or high voltage low current conditions that apply a greater magnitude voltage and greater current than the first or second electrical conditions.

Pre-conditioning circuits and methods for programmable impedance elements in memory devices

Structures and methods for recovering data in a semiconductor memory device are disclosed herein. In one embodiment, a method of recovering data in a semiconductor memory device, can include: (i) pre-conditioning a first memory cell on the semiconductor memory device by using a formation voltage to program a first data state in the first memory cell; (ii) storing a second data state in a second memory cell on the semiconductor memory device by maintaining the second memory cell in a virgin state; (iii) mounting the semiconductor memory device on a printed-circuit board (PCB) by using a high temperature process that increases a resistance of the first memory cell; and (iv) performing a recovery of the first data state by reducing the resistance of the first memory cell.

Safeguarding data through an SMT process

A method of operating a resistive switching device includes applying a program stress to a two terminal resistive memory unit. The program stress is applied at a program voltage configured to change a state of the memory unit from a first state to a second state. The method further includes applying a verification/stabilization stress to the two terminal resistive memory unit. The verification/stabilization stress is applied at a verification/stabilization voltage. An erase stress is applied to the two terminal resistive memory unit. The erase stress is applied at an erase voltage configured to change a state of the memory unit from the second state to the first state. The verification/stabilization voltage is between the program voltage and the erase voltage.

Resistive devices and methods of operation thereof

Structures and methods for controlling operation of a programmable impedance element are disclosed herein. In one embodiment, a method of programming the programmable impedance element can include: (i) receiving a program command to be executed on the programmable impedance element; (ii) performing a program operation on the programmable impedance element in response to the program command; (iii) determining if the program operation successfully programmed the programmable impedance element; and (iv) performing an erase operation for programming the programmable impedance element in response to the program operation failing to successfully program the programmable impedance element.

Reverse program and erase cycling algorithms

A memory device can include a load circuit coupled in series with at least one memory element between two nodes and configured to enable a programming current to flow through the memory element to lower its impedance, and configured to enable an erase current to flow through the element in a direction opposite to the program current, the erase current varying in response to an erase voltage applied across the two nodes as the memory element impedance increases.

Growing community of inventors

Santa Clara, CA, United States of America

Deepak Kamalanathan