Sandisk Technologies Inc.

Bijesh Rajamohanan

Juan Pablo Saenz

Gerrit Jan Hemink

Mohan Dunga

Changyuan Chen

Biswajit Ray

Ashot Melik-Martirosian

Mohsen Purahmad

Alvaro Padilla

After programming a set of resistive memory cells in a resistive memory device, the programmed states and the functionality of each resistive memory cell in the programmed set can be verified by a primary determination method and a secondary determination method. The primary determination method employs the step of determining whether a measured electrical current at a preset read voltage for the selected resistive memory cell is within electrical current specification for the selected resistive state. If the selected cell fails the primary determination method, the second determination method is performed, which includes determining whether a measured threshold voltage for the selected resistive memory cell is within threshold voltage specification for the selected resistive state. If the selected cell fails both methods, the selected cell is identified as a non-functional resistive memory cell. Otherwise, the selected cell is identified as an operational cell.

Write verification and resistive state determination based on cell turn-on characteristics for resistive random access memory

A method of operating a resistive memory device includes providing a resistive memory device including an array of resistive memory cells, where each of the resistive memory cells includes a resistive memory material having at least two different resistive states, performing a first mode read operation on a group of resistive memory cells within the array, determining a bit error rate for data generated by the first mode read operation, determining whether the determined bit error rate is below a predetermined limit, and performing a second mode read operation on the group of resistive memory cells within the array based on a threshold voltage if the determined bit error rate is above the predetermined limit.

ReRAM read state verification based on cell turn-on characteristics

Apparatuses, systems, methods, and computer program products are disclosed for read level determination. A block of non-volatile storage cells has a plurality of bit lines. A controller for a block is configured to perform a first read on a set of storage cells using a first read level for the bit lines. A controller is configured to determine a second read level for at least a portion of the bit lines based at least partially on a first read. A controller is configured to perform a second read on a set of storage cells using a second read level for at least a portion of bit lines.

Cell current based bit line voltage

A method is provided that includes providing a memory device including a first word line, a vertical bit line, a non-volatile memory material disposed between the first word line and the vertical bit line, and a memory cell disposed between the first word line and the vertical bit line. The first word line has a first height. The method further includes forming one or more conductive filaments in the memory cell. The one or more conductive filaments are substantially confined to a filament region having a second height less than the first height and disposed substantially about a vertical center of the memory cell.

Growing community of inventors

San Jose, CA, United States of America

Bijesh Rajamohanan