摘要:
A high voltage input circuit includes a triple-well NMOS for reducing the voltage stress across its drain junction for preventing it from breakdown. The triple-well NMOS is fabricated in a P-well formed in a deep N-well on a P-substrate. The P-well is coupled to a power supply voltage by a P-well voltage control device to reduce the voltage difference across the drain junction. A low voltage signal input circuit portion is also added to the high voltage input circuit to allow a high voltage input pin to receive other signal and reduce the total pin count of an integrated circuit. A dual-input buffer such as NAND gate instead of an inverter is used in the low voltage signal input circuit for reducing the voltage stress to the devices in the low voltage signal input circuit.
摘要:
In this invention a stacked gate flash memory cell is disclosed which has a lightly doped drain (LDD) on the drain side of the device and uses the source to both program using hot electron generation and erase the floating gate using Fowler-Nordheim-tunneling. Disturb conditions are reduced by taking advantage of the LDD and the biasing of the cell that uses the source for both programming and erasure. The electric field of the drain is greatly reduced as a result of the LDD which reduces hot electron generation. The LDD also helps reduce bit line disturb conditions during programming. A transient bit line disturb condition in a non-selected cell is minimized by preconditioning the bit line to the non-selected cell to Vcc.
摘要:
In the present invention a flash memory configuration is disclosed that eliminates the need for one of two pump circuits that are commonly required to support an erase function of memory cells on a flash memory chip. The flash memory cells are placed into a triple well structure with a P-well contained within a deep N-well that resides on a P-substrate. The bias voltages for erase of the flash memory cells are chosen so as to require only one voltage pump circuit to be included in the flash memory chip. The chip bias, V.sub.DD, is used for the source of the memory cells and a negative gate voltage is raised in magnitude to maintain the efficiency of the erase operation. The P-well is biased with a negative voltage that is sufficient to prevent the high negative voltage connected to the gate from causing breakdown in word line decoder circuits. The deep N-well and the P-substrate are biased such as to back bias the P/N junctions between the triple well structure.
摘要:
In this invention a process for a flash memory cell and an architecture for using the flash memory cell is disclosed to provide a nonvolatile memory having a high storage density. Adjacent columns of cells share the same source and the source line connecting these sources runs vertically in the memory layout, connecting to the sources of adjacent columns memory cells. Bit lines connect to drains of cells in adjacent columns and are laid out vertically, alternating with source lines in an every other column scheme. Wordlines made of a second layer of polysilicon form control gates of the flash memory cells and are continuous over the full width of a memory partition. Programming is done in a vertical page using hot electrons to inject charge onto the floating gates. the cells are erased using Fowler-Nordheim tunneling of electrons from the floating gate to the control gate by way of inter polysilicon oxide formed on the walls of the floating gates.
摘要:
In this invention a process for a flash memory cell and an architecture for using the flash memory cell is disclosed to provide a nonvolatile memory having a high storage density. Adjacent columns of cells share the same source and the source line connecting these sources runs vertically in the memory layout, connecting to the sources of adjacent columns memory cells. Bit lines connect to drains of cells in adjacent columns and are laid out vertically, alternating with source lines in an every other column scheme. Wordlines made of a second layer of polysilicon form control gates of the flash memory cells and are continuous over the full width of a memory partition. Programming is done in a vertical page using hot electrons to inject charge onto the floating gates. The cells are crased using Fowler-Nordheim tunneling of electrons from the floating gate to the control gate by way of inter polysilicon oxide formed on the walls of the floating gates.
摘要:
In this invention a process for a flash memory cell and an architecture for using the flash memory cell is disclosed to provide a nonvolatile memory having a high storage density. Adjacent columns of cells share the same source and the source line connecting these sources runs vertically in the memory layout, connecting to the sources of adjacent columns memory cells. Bit lines connect to drains of cells in adjacent columns and are laid out vertically, alternating with source lines in an every other column scheme. Wordlines made of a second layer of polysilicon form control gates of the flash memory cells and are continuous over the full width of a memory partition. Programming is done in a vertical page using hot electrons to inject charge onto the floating gates. the cells are erased using Fowler-Nordheim tunneling of electrons from the floating gate to the control gate by way of inter polysilicon oxide formed on the walls of the floating gates.
摘要:
Phase change devices, and particularly multi-terminal phase change devices, include first and second active terminals bridged together by a phase-change material whose conductivity can be modified in accordance with a control signal applied to a control electrode. This structure allows an application in which an electrical connection can be created between the two active terminals, with the control of the connection being effected using a separate terminal or terminals. Accordingly, the resistance of the heater element can be increased independently from the resistance of the path between the two active terminals. This allows the use of smaller heater elements thus requiring less current to create the same amount of Joule heating per unit area. The resistance of the heating element does not impact the total resistance of the phase change device. The programming control can be placed outside of the main signal path through the phase change device, reducing the impact of the associated capacitance and resistance of the device.
摘要:
In each row of a nonvolatile memory array, the select gates of all the memory cells are connected together and are used to select a row for memory access. The control gates of each row are also connected together, and the source regions of each row are connected together. Also, the control gates of plural rows are connected together, and the source regions of plural rows are connected together, but if the source regions of two rows are connected together, then their control gates are not connected together. If one of the two rows is being accessed but the other one of the two rows is not being accessed, their control gates are driven to different voltages, reducing the probability of a punch-through in the non-accessed row.
摘要:
A system and method for providing a memory cell on a semiconductor is disclosed. The memory cell has a source and a drain. The method and system include providing a source implant in the semiconductor, providing a pocket implant in the semiconductor, and providing a drain implant in the semiconductor after the pocket implant is provided. Thus, short channel effects are reduced.
摘要:
A memory with controlled gate current injection during memory cell programming wherein programming circuitry applies a time-varying voltage to a control gate of the memory cell during a programming cycle. The time-varying voltage yields a substantially constant rate of electron flow from the channel region to the floating gate during the programming cycle.