Abstract: The present invention consists of a method and system for compensating, over time and over an operating temperature range, for margin loss in a non-volatile memory (“NVM”) cell, which method comprises selection of a reference level based on temperature readings obtained from a temperature sensing element that is thermally coupled, directly or indirectly, to the NVM cell. The reference level may be selected from a group consisting of references levels of various types, or it may be obtained by adjusting the output of a single reference based on the temperature reading(s), or it may be obtained by utilizing pre-stored conversion data, which conversion data associates a given temperature reading with a corresponding temperature range that is, in turn, associated with a corresponding reference level. A pool of likewise reference cells may be provided, and the reference level may be selected from this pool, based on its association to the temperature reading.

Abstract: A method for sensing a signal received from an array cell within a memory array, the method comprising the steps of generating an analog voltage Vddr proportional to a current of a selected array cell of the memory array, and comparing the analog voltage Vddr with a reference analog voltage Vcomp to generate an output digital signal. A method is also provided for sensing a memory cell by transforming a signal from a memory cell to a time delay, and sensing the memory cell by comparing the time delay to a time delay of a reference cell. Related apparatus is also disclosed.

Abstract: A method includes minimizing current leaking through a virtual ground pipe during access of NROM memory cells. The minimizing includes operating two neighboring memory cells generally together, which includes connecting an operation voltage to a shared local bit line of the two neighboring memory cells and connecting the external local bit lines of two neighboring memory cells to a receiving unit, such as a ground supply or two sense amplifiers. Also included is an array performing the method.

Abstract: A charge pump stage comprising a pulse train which injects energy into a gate of a charge transfer transistor of the charge pump stage, wherein a modified output of the pulse train is input to a bulk of the charge transfer transistor such that a bulk voltage of the charge transfer transistor is raised to a level not greater than the minimum of a source voltage and a drain voltage of that charge transfer transistor. A method for operating the charge pump stage is also disclosed.

Abstract: A method for programming one or more reference cells is described. The reference cell is programmed a predetermined amount, its program state is sensed relative to a prescribed cell on the same die (e.g., a memory cell or a golden bit cell), and the programming process continues until the reference cell fails a preselected read operation. In one preferred embodiment, the memory cell used during the reference cell programming process is the cell in the memory array having the highest native threshold value. In another preferred embodiment, the memory cell used during the reference cell programming process is a native cell that is on-board the die containing the memory array, but not a cell within the memory array.

Abstract: A method for sensing a signal received from an array cell within a memory array, the method comprising the steps of generating an analog voltage Vddr proportional to a current of a selected array cell of the memory array, and comparing the analog voltage Vddr with a reference analog voltage Vcomp to generate an output digital signal. A method is also provided for sensing a memory cell by transforming a signal from a memory cell to a time delay, and sensing the memory cell by comparing the time delay to a time delay of a reference cell. Related apparatus is also disclosed.

Abstract: A non-volatile electrically erasable programmable read only memory (EEPROM) capable of storing two bit of information having a nonconducting charge trapping dielectric, such as silicon nitride, sandwiched between two silicon dioxide layers acting as electrical insulators is disclosed. The invention includes a method of programming, reading and erasing the two bit EEPROM device. The nonconducting dielectric layer functions as an electrical charge trapping medium. A conducting gate layer is placed over the upper silicon dioxide layer. A left and a right bit are stored in physically different areas of the charge trapping layer, near left and right regions of the memory cell, respectively. Each bit of the memory device is programmed in the conventional manner, using hot electron programming, by applying programming voltages to the gate and to either the left or the right region while the other region is grounded.

Abstract: A buried bitline (BB) may be formed in at least two separate implantation steps, in addition to a pocket implant step. The pocket implant has a first width (W1) and a first depth (D1); the first BB implant has a second width (W2) defined by first sidewall spacers and a second depth (D2); the third BB implant has a third width (W3) defined by second sidewall spacers and a third depth (D3); the second width (W2) is less than the first width (W1), and the third width (W3) is less than or equal to the second width (W2); and the second depth (D2) is greater than the first depth (D1), and the third depth (D3) is greater than the second depth (D2). The first BB implant may provide for pocket implant (PI) to bitline (BL) edge optimization; and the second BB implant may provide for controlling BL resistance.

Abstract: The present invention is a multi-phase method, circuit and system for programming non-volatile memory (“NVM”) cells in an NVM array. The present invention may include a controller to determine when, during a first programming phase, one or more NVM cells of a first set of cells reaches or exceeds to first intermediate voltage, and to cause a charge pump circuit to apply to a terminal of the one or more cells in the first set second phase programming pulses to induce relatively greater threshold voltage changes in cells having less stored charge than in cells having relatively more stored charge.

Abstract: A method for reading a bit of a memory cell in a non-volatile memory (NVM) cell array, the method comprising providing a memory cell comprising a bit to be read and at least one other bit not to be read, and reading the bit to be read with respect to a multi-bit reference cell, the reference cell comprising a first bit at a first non-ground programmed state and a second bit at a second non-ground programmed state. Compared with the prior art, the present invention may enable achieving an improved sensing accuracy together with improved read disturb immunity.

Abstract: An NROM (nitride read only memory) cell, which is programmed by channel hot electron injection and erased by hot hole injection, includes a charge trapping structure formed of: a bottom oxide layer, a charge trapping layer; and a top oxide layer. The bottom oxide layer is no thicker than that which provides margin stability.

Abstract: A non-volatile electrically erasable programmable read only memory (EEPROM) capable of storing two bit of information having a nonconducting charge trapping dielectric, such as silicon nitride, sandwiched between two silicon dioxide layers acting as electrical insulators is disclosed. A left and a right bit are stored in physically different areas of the charge trapping layer, near left and right regions of the memory cell, respectively. Two bits are able to be programmed and read due to a combination of relatively low gate voltages with reading in the reverse direction. This greatly reduces the potential across the trapped charge region. This permits much shorter programming times by amplifying the effect of the charge trapped in the localized trapping region associated with each of the bits.

Abstract: 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.

Abstract: 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.

Abstract: A method for protecting a non-volatile memory device, the method including forming a non-volatile memory device including a polycide structure formed over a non-conducting charge trapping layer, and forming a protective layer over at least a portion of the polycide structure, the protective layer being adapted to absorb electromagnetic wave energy having a wavelength shorter than visible light. A device constructed in accordance with the method is also disclosed.

Abstract: A method for operating a non-volatile memory cell device, the method including providing an array of memory array cells connected to word lines and local bit lines, the local bit lines being connected to global bit lines via select transistors, the array being divided into isolated sectors, providing a sense amplifier operative to sense the memory array cells via a sensing path that includes at least one of the local bit lines, at least one of the select transistors, at least one accessed global bit line, and a YMUX, providing a reference cell located in a reference mini-array, the reference cell being connected to the YMUX and being connected to the sense amplifier via another sensing path, driving both the memory array cells and the reference cells with a common bit line (BL) driver connected to the memory array cells and the reference cells via the YMUX through accessed global bit lines, and matching the sensing path of the memory array cell and the sensing path of the reference cell to the sense amplifier

Abstract: A method for preventing fixed pattern programming, the method including programming data into a pattern of memory cells in a memory array, and preventing fixed pattern programming by periodically scrambling the data so that the data is stored in a different pattern of memory cells in the memory array.

Abstract: 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.

Abstract: 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.

Abstract: 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.