Saifun Semiconductors Ltd.

Spansion Israel Ltd

Assaf Shappir

Boaz Eitan

Eli Lusky

Ilan Bloom

Dror Avni

Rustom Irani

Shai Eisen

Maria Kushnir

Guy Cohen

In a nonvolatile memory (NVM) cell, an injector having one or more layers of material with a lower potential barrier for holes is disposed between a charge storage stack and a source of holes (the gate for top injection, the substrate for bottom injection), to facilitate hole tunneling from the source of holes into the charge-storage layer of the charge storage stack. The injector has a barrier potential for holes which is less than an insulating layer of the charge-storage stack which is oriented towards the source of holes. A multi-layer crested barrier injector may have layers of increasing potential barriers for holes from the source to the charge-storage layer. Methods of operating NVM cells are disclosed. The NVM cell may be NROM, SONOS, or other oxide-nitride technology NVM cells such as SANOS, MANOS, TANOS.

Non-volatile memory cell with injector

Retention of charges in a nonvolatile memory (NVM) cell having a nitride-based injector (such as SiN, SIRN, SiON) for facilitating injection of holes into a charge-storage layer (for NROM, nitride) of a charge-storage stack (for NROM, ONO) may be improved by providing an insulating layer (for NROM, oxide) between the charge-storage layer and the injector has a thickness of at least 3 nm. Top and bottom injectors are disclosed. Methods of operating NVM cells are disclosed. The NVM cell may be NROM, SONOS, or other oxide-nitride technology NVM cells such as SANOS, MANOS, TANOS.

Retention in NVM with top or bottom injection

A method for fabricating a non-volatile memory array includes placing contacts over bit lines in a self-aligned manner. The placing includes forming self-aligned contact holes bounded by a second insulating material resistant to the removal of a first insulating material previously deposited over the bit lines, and depositing contact material, wherein the second insulating material blocks effusion of the contact material beyond the contact holes. The distance between neighboring bit lines in the array does not include a margin for contact misalignment.

Contact in planar NROM technology

A method for creating a non-volatile memory array includes implanting pocket implants in a substrate at least between mask columns of a given width and at least through an ONO layer covering the substrate, generating increased-width polysilicon columns from the mask columns, generating bit lines in the substrate at least between the increased-width polysilicon columns and depositing oxide at least between the polysilicon columns.

Non-volatile memory structure and method of fabrication

The present invention is a method circuit and system for erasing one or more non-volatile memory ('NVM') cells in an NVM array. One or more NVM cells of a memory array may be erased using an erase pulse produced by a controller and/or erase pulse source adapted to induce and/or invoke a substantially stable channel current in the one or more NVM cells during an erasure procedure. The voltage profile of an erase pulse may be predefined or the voltage profile of the erase pulse may be dynamically adjusted based on feedback from a current sensor during an erase procedure.

Method, circuit and system for erasing one or more non-volatile memory cells

An NVM cell such as an NROM cell is formed using a portion of one ONO stack and an adjacent portion of a neighboring NROM stack. A gate structure is formed between (and atop) the two ONO portions, or 'strips' (or 'stripes'). This provides having two physically separated charge storage regions (nitride &#x201c;strips&#x201d;, or &#x201c;stripes&#x201d;) in each memory cell.

Double density NROM with nitride strips (DDNS)

A method for erasing memory cells in a memory array, the method including applying an erase pulse to bits of a cell ensemble of a memory cell array, and performing an erase verification operation only on a subgroup of the cell ensemble being erased to check if the memory cells threshold voltage (Vt) has been lowered to an erase verify (EV) voltage level.

Partial erase verify

A method and a system for operating bits of memory cells in a memory array, the method including applying a first operating pulse to a terminal of a first cell, the first operating pulse is intended to place the first cell into a predefined state; and applying a second operating pulse to a terminal of a second cell in the set, the second operating pulse is intended to place the second cell to the predefined state, and the pulse characteristics of the second operating pulse are a function of the response of the first cell to the first operating pulse.

Method, system, and circuit for operating a non-volatile memory array

The present invention is a method, circuit and system for erasing one or more non-volatile memory ('NVM') cells in an NVM array or array segment. According to some embodiments of the present invention, one or more erase pulse parameters may be associated with each of a number of array segments within an NVM array. Separate erase pulse parameters may be associated with anywhere from one to all of the array segments within an NVM array. According to some embodiments of the present invention, a characteristic of an erase pulse (e.g. pulse amplitude, pulse duration, etc.) applied to one or more NVM cells within an array segment may be at least partially based on one or more erase pulse parameters associated with the given array segment.

Method, circuit and systems for erasing one or more non-volatile memory cells

A method for protecting NROM devices from charge damage during process steps, the method including providing X-decoder structure for word line connections, wherein each word line is connected to a pair of transistors, a PMOS transistor and an NMOS transistor the PMOS transistors sharing a common deep N well and the NMOS transistors connected to a P well, wherein during negative charging, the NMOS transistors shunt leakage current to ground, and during positive charging, the PMOS transistors shunt leakage current to ground, providing an N+ tap connected to the N well and connecting the N+ tap to a positive voltage clamping device, and connecting all the P wells together to a common P+ tap and connecting the P+ tap to a negative voltage clamping device, wherein during process steps, the negative and positive voltage clamping devices direct leakage current to ground.

Protection of NROM devices from charge damage

A method includes changing a read reference level for reading a group of memory cells as a function of changes in a threshold voltage distribution of a different group of memory cells. The changing step includes determining a history read reference level of a group of history cells associated with a group of memory cells of a non-volatile memory cell array, allowing correct reading of the group of history cells, selecting a memory read reference level according to the first read reference level, and reading the non-volatile memory array cells.

Method for reading non-volatile memory cells

Method for operating a memory device

A method for operating on bits of a memory cell, the method comprising providing a memory cell that has two separated and separately chargeable areas on first and second sides of the cell, each chargeable area defining one bit, applying an injection pulse and a verify pulse on the first side of the cell, and before the first side of the cell has reached a verify level, applying an injection pulse and a verify pulse on the second side of the cell.

Alternating application of pulses on two sides of a cell

A method for operating bits of memory cells in a memory array, the method including applying operating pulses to bits of a sample of memory cells, determining a response of at least one of an electrical, physical and mechanical property (e.g., threshold voltage) of the bits to the operating pulses, and applying at least one further operating pulse to the rest of the array, the at least one further operating pulse being a function of the response.

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Kiryat Ono, Israel

Assaf Shappir