Sandisk 3d LLC

Pankaj Kalra

Yingchang Chen

Chandrasekhar R Gorla

Roy E Scheuerlein

Raghuveer S Makala

Masaaki Higashitani

Tanmay Kumar

Jingyan Zhang

Chandrasekhar Gorta

Methods for reducing location-based variations in the switching characteristics of memory cells within a memory array are described. In some cases, the resistance of an embedded resistor within each memory cell may be set to reduce the overall variation in series resistances for the memory cells within a memory array. For example, embedded resistors associated with far-far bits may be set to a lower resistance than embedded resistors associated with near-near bits. An embedded resistor may comprise a layer of polysilicon within a memory cell. Selective ion implantation may be used to reduce the embedded resistor resistance for memory cells within a particular region of the memory array and to form two or more different sets of embedded resistors within the memory array.

Methods and systems to reduce location-based variations in switching characteristics of 3D ReRAM arrays

Methods for performing parallel voltage and current compensation during reading and/or writing of memory cells in a memory array are described. In some embodiments, the compensation may include adjusting a bit line voltage and/or bit line reference current applied to a memory cell based on a memory array zone, a bit line layer, and a memory cell direction associated with the memory cell. The compensation may include adjusting the bit line voltage and/or bit line reference current on a per memory cell basis depending on memory cell specific characteristics. In some embodiments, a read/write circuit for reading and/or writing a memory cell may select a bit line voltage from a plurality of bit line voltage options to be applied to the memory cell based on whether the memory cell has been characterized as a strong, weak, or typical memory cell.

Compensation scheme for non-volatile memory

A method of programming a nonvolatile memory cell. The nonvolatile memory cell includes a diode steering element in series with a carbon storage element The method includes providing a first voltage to the nonvolatile memory cell. The first voltage reverse biases the diode steering element. The carbon storage element sets to a lower resistivity state.

Method of programming a nonvolatile memory cell by reverse biasing a diode steering element to set a storage element

In a first aspect, a memory cell is provided, the memory cell including: (a) a first conducting layer formed above a substrate; (b) a second conducting layer formed above the first conducting layer; (c) a structure formed between the first and second conducting layers, wherein the structure includes a sidewall that defines an opening extending between the first and second conducting layers, and wherein the structure is comprised of a material that facilitates selective, directional growth of carbon nano-tubes; and (d) a carbon-based switching layer that includes carbon nano-tubes formed on the sidewall of the structure. Numerous other aspects are provided.

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San Jose, CA, United States of America

Pankaj Kalra