Abstract: A nonvolatile memory device has a combination of FLOTOX EEPROM nonvolatile memory arrays. Each FLOTOX-based nonvolatile memory array is formed of FLOTOX-based nonvolatile memory cells that include at least one floating gate tunneling oxide transistor such that a coupling ratio of the control gate to the floating gate of the floating gate tunneling oxide transistor is from approximately 60% to approximately 70% and a coupling ratio of the floating gate to the drain region of the floating gate tunneling oxide transistor is maintained as a constant of is from approximately 10% to approximately 20% and such that a channel length of the channel region is decreased such that during the programming procedure a negative programming voltage level is applied to the control gate and a moderate positive programming voltage level is applied to the drain region to prevent the moderate positive programming voltage level from exceeding a drain-to-source breakdown voltage.

Abstract: One or more embodiments of 8T NVSRAM cell are provided for improving NVSRAM memory architecture with reduced cell size as opposed to the prior art of 12T NVSRAM cell. This novel 8T NVSRAM cell uses one step Write operation under either a FN-channel write scheme to increase a paired flash transistor Vt values in positive direction with a desired ?Vt12 ?1V or a FN-edge write scheme to decrease the Vt values in negative direction with a similar desired ?Vt12?1V to write the ?Vt12 into the paired flash transistors within 1-10 ms without requiring a pre-erase step. There is no need of Program-Inhibit Voltage (SBPI) to inhibit non-select flash transistor from programming. In addition, this 8T NVSRAM cell uses DRAM-like charge-sensing scheme to detect the ?V on Q and QB nodes of SRAM in which is coupled and generated from the ?Vt12 stored in MC1 and MC2 flash transistors.

Abstract: This invention discloses a HiNAND array scheme with multiple-level of bit lines (BLs) including metal3 global bit lines (GBLs), divided metal2 Segment bit lines (SBLs), and divided metal1 block bit lines (BBLs) laid out in parallel to each other respectively for a plurality of NAND Strings. All other source lines or power lines connected to bottoms of corresponding String capacitances of GBLs, SBLs, and BBLs are associated with metal0 line laid out perpendicular to those BLs. Under the HiNAND array scheme, conventional one-WL Read and Program-Verify operations are replaced by multiple-WL and All-BL Read and Program-Verify operations executed with charge capacitance of SBLs being reduced to 1/10- 1/20 of capacitance of GBLs to achieve DRAM-like faster operation, less operation stress, and lower power consumption. A preferred set of program biased voltages on the selected WL and remaining non-selected WLs associated with a Multiplier and a DRAM-like charge-sharing Latch Sensing Amplifier is proposed.

Abstract: An one-transistor-one-bit (1T1b) Flash-based EEPROM cell is provided along with improved key operation schemes including applying a negative word line voltage and a reduced bit line voltage for perform erase operation, which drastically reduces the high voltage stress on each cell for enhancing the Program/Erase cycles while reducing cell size. An array made by the 1T1b Flash-based EEPROM cells can be operated with Half-page or Full-page divided programming and pre-charging period for each program cycle. Utilizing PGM buffer made of Vdd devices in the cell array further save silicon area. Additionally, a two-transistor-two-bit (2T2b) EEPROM cell derived from the 1T1b cell is disclosed with additional cell size reduction but with the operation of program and erase the same as that for the 1T1b cells with benefits of no process change but much enhanced storage density, superior Program/Erase endurance cycle, and capability for operating in high temperature environment.

Abstract: A novel NVM-based 2T or 2nT NAND-cell for a NAND-array for PLD, PAL and matching functions is disclosed. The preferable NVM cell can be ROM or Flash. The 2T flash cell preferably uses FN for both program and erase operation, while 2T ROM cell preferably to use phosphorus for ROM code implant to get negative Vt0.

Abstract: A HiNAND array with a hierarchical-BL scheme configured to divide a large global bit line (GBL) capacitance into J number of small local bit line (LBL) capacitances for reducing bit line precharge voltage and discharge time to achieve faster Read and Program-Verify speed, lower power consumption, lower latency, and lower word line disturbance for a reliable DRAM-like latch sensing. A reduced precharge voltage can be increased by M-fold (M?2) using a Multiplier between each bitline and each Latch sense amplifier (SA). Between each Multiplier and each Latch SA, there is a Connector with two optional designs for either fully passing a sense voltage to the Latch SA with a same-polarity and value or reversing the polarity the sensing voltage with additional amplification. The Latch SA is configured to transfer stored threshold states of a memory cell into a bit of a page buffer.

Abstract: This invention discloses a 2T-string NOR-based CAM logic cell comprising two physical NAND cells connected in series with two horizontal WLs and one vertical BL and one vertical SL. Additionally, a sector of NOR-based CAM logic cell array is configured with N vertical cell strings each including M 2T-string NOR-based CAM logic cells connected in parallel sharing a local vertical SL and one dedicated vertical ML as an Operand word vertical page. Each 2T-string NOR-based CAM logic cell can be either a binary or ternary CAM cell associated with two or three physical states assigned to NAND cells' Vt levels for defining CAM logic states. Logic match of M-logic-bit inputs is found for at least one vertical page if the corresponding M 2T-string NOR-based CAM logic cells are in non-conduction state, providing M times faster Compare performance over the NAND-based CAM and 2 time faster than SRAM-based CAM.

Abstract: This invention discloses circuit and methods of a NAND-based 2T-string NOR flash cell structure as a building block for a fast random-read NOR flash memory. The key concept of this new set of bias conditions in cell array improves over the critical concern of punch-through issue when cell is migrating to the more advanced technology node of next generation. The invention adopts a novel preferable symmetrical 2T-string NOR flash cell. Each NAND or NAND like cell of this 2T-string NOR cell is to store 2 bits and is preferable to be made of N-channel device. The cell is preferable to use Fowler-Nordheim Tunneling scheme for both erase and program operations. The invention is to provide a novel 2T-string NOR flash cell structure made of N-channel device offering most flexible erase sizes in unit of byte, page, sector, block and chip with the least program and erase disturbances.

Abstract: A nonvolatile memory device has a combination of FLOTOX EEPROM nonvolatile memory arrays. Each FLOTOX-based nonvolatile memory array is formed of FLOTOX-based nonvolatile memory cells that include at least one floating gate tunneling oxide transistor such that a coupling ratio of the control gate to the floating gate of the floating gate tunneling oxide transistor is from approximately 60% to approximately 70% and a coupling ratio of the floating gate to the drain region of the floating gate tunneling oxide transistor is maintained as a constant of is from approximately 10% to approximately 20% and such that a channel length of the channel region is decreased such that during the programming procedure a negative programming voltage level is applied to the control gate and a moderate positive programming voltage level is applied to the drain region to prevent the moderate positive programming voltage level from exceeding a drain-to-source breakdown voltage.

Abstract: A two transistor NOR flash memory cell has symmetrical source and drain structure manufactured by a NAND-based manufacturing process. The flash cell comprises a storage transistor made of a double-poly NMOS floating gate transistor and an access transistor made of a double-poly NMOS floating gate transistor, a poly1 NMOS transistor with poly1 and poly2 being shorted or a single-poly poly1 or poly2 NMOS transistor. The flash cell is programmed and erased by using a Fowler-Nordheim channel tunneling scheme. A NAND-based flash memory device includes an array of the flash cells arranged with parallel bit lines and source lines that are perpendicular to word lines. Write-row-decoder and read-row-decoder are designed for the flash memory device to provide appropriate voltages for the flash memory array in pre-program with verify, erase with verify, program and read operations in the unit of page, block, sector or chip.

Abstract: One or more embodiments of 8T NVSRAM cell are provided for improving NVSRAM memory architecture with reduced cell size as opposed to the prior art of 12T NVSRAM cell. This novel 8T NVSRAM cell uses one step Write operation under either a FN-channel write scheme to increase a paired flash transistor Vt values in positive direction with a desired ?Vt12?1V or a FN-edge write scheme to decrease the Vt values in negative direction with a similar desired ?Vt12?1V to write the ?Vt12 into the paired flash transistors within 1-10 ms without requiring a pre-erase step. There is no need of Program-Inhibit Voltage (SBPI) to inhibit non-select flash transistor from programming. In addition, this 8T NVSRAM cell uses DRAM-like charge-sensing scheme to detect the ?V on Q and QB nodes of SRAM in which is coupled and generated from the ?Vt12 stored in MC1 and MC2 flash transistors.

Abstract: The present invention discloses a 10T NVSRAM cell with a 6T SRAM cell with 4T Flash cell with one dedicated Flash-based Charger. In addition, a Pseudo-8T NVSRAM cell with a shared Flash-based Charger between two adjacent 8T NVSRAM cells at top and bottom in cell layout is also disclosed to further reduce cell size by 20%. As opposed to the prior art of 12T NVSRAM cell, the Store operation of the above two preferred embodiments use a DRAM-like charge-sensing scheme with Flash cell configured into a voltage follower ensured by the Flash-based Charger to obtain the final ?VQ-QB>0.2V at Q and QB nodes of each SRAM cell to cover all the mismatched of parasitic capacitance in flash cell devices and layout for a reliable amplification by ramping up SRAM's VDD line and ramping down SRAM's VSS line.

Abstract: The present invention discloses two preferred embodiments of a 12 T NVSRAM cell with a flash-based Charger and a pseudo 10 T NVSRAM cell with one shared Flash-based Charger. The Flash-based Charger can be made of a 2-poly floating-gate type or a 1-poly charge-trapping SONOS/MONOS flash type, regardless of PMOS type or NMOS type. In an alternative embodiment, the Store operation of above two preferred NVSRAM cell use a DRAM-like charge-sensing scheme with Flash cell configured into a voltage follower associated with Flash Charger and 2-step SRAM amplification technique to amplify the threshold level difference ?Vt stored in the paired Flash transistors. The ?Vt can be detected as low as 1V when the coupled charges through the Flash charger are sufficient by ramping a gate control of the Flash Charger as high as VPP or by increasing the channel length for the Flash Charger.

Abstract: A 10T NVSRAM cell is provided with a bottom HV NMOS Select transistor in each 3T FString removed from traditional 12T NVSRAM cell. A Recall operation by reading a stored ?Vt state of flash transistors into each SRAM cell uses a charge-sensing scheme rather than the current-sensing scheme, with all other key operations unchanged. The Recall operation works under any ramping rate of SRAM's power line voltage and Flash gate signal which can be set higher than only Vt0 or both Vt0 and Vt1. Alternatively, the Store operation can use a current charging scheme from a Fpower line to the paired Q and QB nodes of each SRAM cell through a paired Flash Voltage Follower that stored ?Vtp?1.0V. The Recall operation in this alternative embodiment is to use a 7-step approach with the FN-channel erase, FN-channel program and FN-edge program schemes, including 2-step SRAM amplification.

Abstract: Two on-chip capacitors including one HV capacitor VPPcap and one LV VCC capacitor VCCcap are built over a NVSRAM memory chip as a back-up second power supplies for each NVSRAM cell, regardless of 1-poly, 2-poly, PMOS or NMOS flash cell structures therein. The on-chip HV and LV capacitors are preferably made from one or more MIM or MIP layers for achieving required capacitance. A simplified VCC power system circuit without a need of a State machine designed for performing only one NVSRAM Program operation without Erase operations is proposed for initiating NVSRAM's Auto-Store operation without using any off-chip Vbat and Vcap. During the Auto-Store operation, all HV pumps and oscillators associated with the two on-chip capacitors are shut off once VCC voltage drop is detected by a VCC detector to be below 80% of regular VDD level.

Abstract: Several preferred embodiments of 1S1F 16T NVSRAM, 1S1F 20T NVSRAM, 1S2F 22T NVSRAM, 1S2F 14T NVSRAM cells are proposed, regardless of 1-poly, 2-poly, PMOS or NOS flash cell structures. Two separate sourcelines for the paired flash Strings are also proposed for easy adding ability for the NVSRAM circuit to detect the marginally erased Vt0 and marginally programmed Vt1 of the paired flash cell. By increasing an resistance added to common SRAM power line, the pull-down current through flash Strings to grounding source line can be made much larger than the pull-up current to improve SFwrite program operation. Simple method by increasing flash cell channel length to effectively enhance coupling area is applied to secure SRAM-to-Flash store operation under self-boost-program-inhibit scheme. 1S2F architecture also provide flexibility for alternate erasing and programming during both a recall and store operation.

Abstract: This invention discloses a low-voltage fast-write 12T or 14T PMOS NVSRAM cell structure which comprises a 6T LV SRAM cell and one pairs of two 3T or 4T HV PMOS Flash strings. Due to reverse threshold voltage definition of PMOS and NMOS flash cell, this PMOS NVSRAM cell has the advantage over the NMOS NVSRAM cell to have the same data polarity between SRAM and Flash pairs during the data writing operation. In addition, this PMOS NVSRAM's PMOS Flash cell uses similar low-current FN-tunneling scheme as NMOS NVSRAM, thus the fast data program and erase can be achieved in a big density up to 100 Mb simultaneously. As a result, low power voltage operation of NVSRAM with 1.2V VDD can be much easier to be designed without coupling the FSL line to any VDD level during the flash data loading into SRAM cell during a power-on period.

Abstract: Methods of increasing the speed of random read and write operations of a memory device are provided for improving the performance of volatile and non-volatile memory devices. In contrast to the conventional approach that latches the current memory address right before the currently accessed memory data are outputted, the methods latch the next memory address before the currently accessed memory data are read out. The flow, timing waveforms and control sequences of applying the methods to parallel NOR flash, parallel pSRAM, serial SQI NOR flash and NAND flash are described in detail. The NOR flash device designed with the method can be integrated with a NAND flash device on a same die in a combo flash device packaged in either an ONFI compatible NAND flash package or other standard NAND flash package.

Abstract: A single polycrystalline silicon floating gate nonvolatile memory device has a storage MOS transistor and at least one polycrystalline-insulator-polycrystalline (PIP) or metal-insulator-metal (MIM) capacitor manufactured with dimensions that can be fabricated using current low voltage logic integrated circuit process. The PIP or MIM capacitor is a coupling capacitor with a first plate connected to a floating gate of the storage MOS transistor to form a floating gate node. The coupling PIP or MIM capacitor couples the voltage level applied to a second plate of the PIP or MIM capacitor to the floating gate node with a large coupling ratio approximately 90% so as to initiate Fowler-Nordheim tunneling effect for erasing or programming the memory device. The memory device may also have another PIP or MIM capacitor with a first plate connected to the floating gate of the storage MOS transistor for serving as a tunneling capacitor.

Abstract: A method and apparatus for operating an array block of dual charge retaining transistor NOR flash memory cells by erasing the dual charge retaining transistor NOR flash memory cells to set their threshold voltage levels to prevent leakage current from corrupting data during a read operation. Erasure of the array block of NOR flash memory cells begins by selecting one of block section of the array block and strongly and deeply erasing, over-erase verifying, and programming iteratively until the charge retaining transistors have their threshold voltages between the lower voltage limit and the upper voltage limit of the first program state. Other block sections are iteratively selected and erased, over-erase verified, and programmed repeatedly until the charge retaining transistors have their threshold voltages between the lower voltage limit and the upper voltage limit of the first program state until the entire block has been erased and reprogrammed to a positive threshold level.