Hitachi, Ltd.

Other

Renesas Technology Corp.

Hitachi Ulsi Systems Co., Ltd.

Hitachi Ulsi Engineering Corp.

Hitachi Device Engineering Co., Ltd.

Hitachi Vlsi Engineering Corp.

Shoji Kubono

Atsushi Nozoe

Michitaro Kanamitsu

Takayuki Kawahara

Tetsuya Tsujikawa

Hiroshi Sato

Keiichi Yoshida

Hiroaki Kotani

Ken Matsubara

Satoshi Noda

Eiji Yamamoto

Toshinori Harada

Katsutaka Kimura

Yoshinori Takase

Naoki Miyamoto

Hideaki Kurata

Takayuki Yoshitake

Naoki Kobayashi

Takashi Kobayashi

Shunichi Saeki

Koji Shigematsu

Kiichi Manita

Tatsuya Ishii

Masaya Muranaka

Yukihide Suzuki

Makoto Morino

Sinichi Miyatake

Shoji Wada

Masahiro Ogata

Kanehide Kenmizaki

Takashi Ogino

Yoshihisa Koyama

Hidetomo Aoyagi

Tetsuya Kitame

Masahiro Katayama

Nobuhiko Ohno

Seiichi Shundo

Jiro Kishimoto

A nonvolatile memory device of the present invention performs a programming operation by accumulating a charge in certain capacitance which is provided for each programming memory cell and injecting hot electrons generated when the charge is discharged via the memory cell into a floating gate. Thus, a variation in a programming characteristic of the nonvolatile semiconductor memory device is reduced, thereby realizing high-speed programming operation.

Nonvolatile semiconductor storage device

There is provided a method of programming a non-volatile memory which can solve the problem of the data write system of the existing flash memory that a load capacitance of bit lines becomes large, the time required by the bit lines to reach the predetermined potential becomes longer, thereby the time required for data write operation becomes longer and power consumption also becomes large because the more the memory capacitance of memory array increases, the longer the length of bit lines becomes and the more the number of bit lines increases. In the non-volatile memory of the invention comprising the AND type memory array in which a plurality of memory cells are connected in parallel between the local bit lines and local drain lines, the local drain lines are precharged by supplying thereto a comparatively higher voltage from the common drain line side (opposite side of the main bit lines), the main bit lines are selectively precharged by applying thereto the voltage of 0V or a comparatively small voltage depending on the write data and thereafter a drain current is applied only to the selected memory cells to which data is written by applying the write voltage to the word lines in order to implant the hot electrons to the floating gate.

Nonvolatile memory and method of programming the same memory

A nonvolatile semiconductor storage unit can prevent erratic sense operations in a sense latch circuit by adopting a single-end sensing system capable of reducing an area (decreasing the number of elements). There is provided a flash memory chip using the single-end sensing system and an NMOS gate sensing system together. In the single-end sensing system, the sense latch circuit is connected to one end of a global bit line to detect data on the global bit line corresponding to a threshold voltage for a memory cell. The NMOS gate sensing system uses an NMOSFET to receive data on the global bit line at a gate and drive a node for the sense latch circuit. The NMOSFET senses a sense voltage. The sense latch circuit is activated with a sufficient signal quantity ensured. An output voltage from a threshold voltage applying power supply precharges the global bit line. In this manner, it is possible to always keep a constant difference between a precharge voltage and a threshold voltage for the NMOSFET.

Nonvolatile semiconductor storage unit

Externally supplied program data is latched into data latch circuits DLL and DLR. A judgment is made as to whether or not the latched program data corresponds to any threshold value of multi-levels every time each of plural programing operations is carried out. The program control information corresponding to the judgment result is latched into a sense latch circuit SL. Based upon the latched program control information, the programing operation for setting threshold voltages having multi-levels to a memory cell is carried out in a stepwise manner. Even when the programing operation is ended, the externally supplied program data is left in the data latch circuit. Even when the programing operation of the memory cell is retried due to the overprograming condition, the program data is no longer required to be again received from the external device.

Semiconductor, memory card, and data processing system

In a nonvolatile semiconductor memory in which multiple-value information is stored in one memory cell by setting a plurality of threshold values, data is successively read from word lines while continuously changing the word-line read level from a lowest level to a highest level, and the next bit line is selectively precharged in accordance with the data stored in latch means for storing read data.

Nonvolatile semiconductor memory and read method

A non-volatile memory system is provided with a control device and non-volatile memory devices, each including memory cells and data latches. The control device supplies commands to the non-volatile memory devices, including a write command, and first and second read commands. When the control device supplies the write command with write address information and data for storing in the non-volatile memory device, it stores the data to the data latches and then to the memory cells, and then verifies storage. When the control device supplies the first read command with read address information, the nonvolatile memory device reads data stored in the memory cells to the data latches and then outputs the data in the data latches to the control device. When the control device supplies the second read command, the non-volatile memory device outputs data in the data latches to the control device.

Non-volatile memory system including a control device to control writing, reading and storage and output operations of non-volatile devices including memory cells and data latches

Data are generated based on additional write data input to data latch circuits (DLR and DLL) and data read from memory cells (MC) to program non-volatile memory cells in a write state into the same write state and to program non-volatile memory cells in an erase state into a write state indicated by the additional write data. The generated data are latched in the data latch circuits to perform a logical synthesis process for additional writing. Even after the additional write operation, the logically synthesized data remain in the data latch circuits, and the latched data can be reused against abnormality in writing. This eliminates the need for receiving write data again from the outside when the additional write operation is to be retried.

Semiconductor device, data processing system and a method for changing threshold of a non-volatile memory cell

A semiconductor memory is designed to avoid a situation that the program cannot escape from a writing operation, and the writing operation can be promptly finished according to the level of an external source voltage. This semiconductor memory has a voltage detecting circuit for detecting whether a boosted voltage has reached a predetermined potential and a timer capable of counting predetermined time. A control circuit applies the boosted voltage to a selected memory cell when the voltage detecting circuit detects that the boosted voltage has reached the predetermined potential or when it is detected that the predetermined time has elapsed since the start of the boosting operation.

Nonvolatile semiconductor memory with controlled supply of boosted voltage

Nonvolatile memory system

A non-volatile memory device having a plurality of memory cells and a control circuit. The control circuit receives operation commands from outside the device and controls the operation of the device according to the commands. The commands include read commands and write commands. In a read command, the control circuit reads data in the memory cells and outputs it. In a write command, the control circuit controls the inputting of data to data latch circuits and then to memory cells. The control circuit provides status information indicating whether the writing of data is a success or a failure.

Non-volatile memory device

A control of a flash memory includes control for supplying a pulse-shaped voltage to each of non-volatile memory cells until a threshold voltage of the non-volatile memory cell having a first threshold voltage is changed to a second threshold voltage. The control involves a first write mode (coarse write) in which the amount of change in threshold voltage of each non-volatile memory cell, which is varied each time the pulse-shaped voltage is applied, is relatively rendered high, and a second write mode (high-accuracy write) in which the amount of change in threshold voltage thereof is relatively rendered low. As compared with the high-accuracy mode, the number of pulses required to change the threshold voltage of each memory cell is smaller than that in the coarse write mode. Therefore, the number of verify operations at the time that the coarse write mode is used, is small and hence the entire write operation can be speeded up.

Semiconductor integrated circuit and data processing system

Growing community of inventors

Akishima, Japan

Shoji Kubono