Abstract: There is provided a semiconductor device including DTMOS and a substrate variable-bias transistor and a portable electronic device both operable with reduced power consumption. N-type deep well regions are formed in one P-type semiconductor substrate. The N-type deep well regions are electrically isolated by the P-type semiconductor substrate. Over the N-type deep well regions, a P-type deep well region and a P-type shallow well region are formed to fabricate an N-type substrate variable-bias transistor. Over the N-type deep well region, an N-type shallow well region is formed to fabricate a P-type substrate variable-bias transistor. Further a P-type DTMOS and an N-type DTMOD are fabricated.

Abstract: A semiconductor memory device includes a field-effect transistor provided on a surface of a P-type transistor substrate. The field-effect transistor includes two N-type diffusion layer regions, a gate electrode, and a charge storage section. By applying a reference voltage to one of the N-type diffusion layer regions, a voltage higher than the reference voltage to the other of the N-type diffusion layer regions, a voltage lower than the reference voltage to the gate electrode, and a voltage higher than the reference voltage to the P-type semiconductor substrate, holes are injected into the charge storage section. Because the forward voltage is applied to a PN junction between one of the N-type diffusion layer regions and the P-type semiconductor substrate, it is possible to inject the holes into the charge storage section at the voltages lower than the voltages required if the forward voltage is not applied. Therefore, it is possible to decrease operating voltages of the semiconductor memory device.

Abstract: This invention is a method of improving a data retention ability of a semiconductor memory device having a plurality of nonvolatile memory cells storing a plurality of memory states. The method includes the steps of: (a) selecting the nonvolatile memory cells in a first memory group each of which accumulates charges higher in level than a first threshold from the plurality of nonvolatile memory cells; (b) extracting the nonvolatile memory cells in a first sub-group each of which accumulates the charges lower in level than a second threshold from the nonvolatile memory cells in the first memory group; and (c) programming the nonvolatile memory cells in the first sub-group until each of the nonvolatile memory cells accumulates the charges higher in level than the second threshold.

Abstract: A memory film operable at a low voltage and a method of manufacturing the memory film; the method, comprising the steps of forming a first insulation film (112) on a semiconductor substrate (111) forming a first electrode, forming a first conductor film (113) on the first insulation film (112), forming a second insulation film (112B) on the surface of the first conductor film (113), forming a third insulation film containing conductor particulates (114, 115) on the second insulation film (112B), and forming a second conductor film forming a second electrode on the third insulation film.

Abstract: In a semiconductor storage device, a gate insulating film (12) and a gate electrode (13) are laid on a first conductivity type semiconductor substrate (11), and charge holding portions (10A, 10B) are formed on both sides of the gate electrode (13). Second conductivity type first and second diffusion layer regions (17, 18) are formed in regions of the semiconductor substrate (11) corresponding to the charge holding portions (10A, 10B). The charge holding portions (10A, 10B) are each structured so as to change, in accordance with an electric charge amount held in the charge holding portions, a current amount flowing from one of the second conductivity type diffusion layer regions (17, 18) to the other of the diffusion layer regions through a channel region when voltage is applied to the gate electrode (13). Part of each charge holding portion (10A, 10B) is present below an interface of the gate insulating film (12) and the channel region.

Abstract: A semiconductor memory device includes a memory cell including a gate electrode formed on a semiconductor layer via a gate insulating film, a channel region disposed under the gate electrode, diffusion regions disposed on both sides of the channel region and having a conductive type opposite to that of the channel region, and memory functional units formed on both sides of the gate electrode and having a function of retaining charges; a switching transistor circuit including a negative voltage switching circuit for applying a negative voltage to the gate electrode of the memory cell, and a switching transistor connected to an output of the negative voltage switching circuit and a first voltage source for outputting a voltage having a voltage level lower than zero volt; a pull-up circuit connected to a control terminal of the switching transistor and selectively connected to a second voltage source for outputting a voltage having a voltage level higher than zero volt; and a pull-down circuit connected to the f

Abstract: A semiconductor memory device includes a memory array; a storage section that receives a maximum pulse value from a user of the semiconductor memory device; a control section that executes a writing processing or an erasing processing for the memory array and restarts the writing or erasing processing in the case where the processing for the memory array has failed; a counter section that counts up a number of processings performed by the control section; and a detection section that detects when the number of processings is equal to the maximum pulse value to prevent the control section from restarting the writing or erasing processing.

Abstract: A semiconductor memory device including memory cells, each memory cell including: a gate insulating film formed on a semiconductor substrate; a gate electrode formed on the gate insulating film; a channel region located below the gate electrode; a pair of source and drain regions arranged on a opposite sides, respectively, of the channel region, the source and drain regions having a conductive type opposite to that of the channel region; and memory functional units located on opposite sides, respectively, of the gate electrode, each memory functional unit including a charge retaining portion and an anti-dissipation insulator, the charge retaining portion being made of a material serving to store charges, the anti-dissipation insulator serving to prevent the stored charges from being dissipated by separating the charge retaining portion from both the gate electrode and the substrate, wherein a distance between a side wall of the gate electrode and a side of the charge retaining portion facing each other (T2) i

Abstract: When an input voltage determining circuit 24 determines that an input voltage exceeds a prescribed voltage, a control circuit 25 of a positive polarity power selector circuit 22 turns on a first switch SW1 and turns off second and third switches SW2 and SW3, thereby supplying the input voltage to a memory cell array 21 via the first switch SW1. When the input voltage determining circuit 24 determines that the input voltage is not higher than the prescribed voltage, the control circuit 25 turns off the first switch SW1 and turns on the second and third switches SW2 and SW3, thereby supplying a voltage from a charge pump 23 via the second and third switches SW2 and SW3. By this operation, the memory element is able to retain storage of two bits or more even if miniaturized, to execute stable operation with a small circuit area and to prevent circuit malfunction attributed to a small current supplied to the memory cell array.

Abstract: The present invention provides a semiconductor memory device including a memory cell array in which a plurality of memory cells are arranged, a user interface circuit including a command queue having a logic circuit for accepting commands issued by an external user and generating a program memory address, and an array control circuit having a microcontroller and a program memory for storing therein an execution code, and executing an operation on the memory cell array, wherein the memory cell includes a gate electrode formed over a semiconductor layer via a gate insulating film, a channel region disposed below the gate electrode, diffusion regions disposed on both sides of the channel region and having a conductive type opposite to that of the channel region, and memory functional elements formed on both sides of the gate electrode and having the function of retaining charges.

Abstract: A writing control system providing high-speed writing to a nonvolatile semiconductor storage device, includes (a) a plurality of memory elements each having: a gate electrode provided on a semiconductor layer with an intervening gate insulating film; a channel region provided beneath the gate electrode; a diffusion region provided on both sides of the channel region, having an opposite polarity to the channel region; and a memory functioning member, provided on both sides of the gate electrode, having a function of holding electric charges, (b) a memory array including a page buffer circuit, and (c) CPU controlling writing to the memory array. The CPU loads a first plane of the page buffer circuit with a first byte of data and writes with the first byte of data stored in the first plane.

Abstract: A semiconductor storage device includes a voltage supply circuit generating a voltage of 5V, a voltage polarity inversion circuit generating a voltage of ?5V, a select-and-connect circuit supplying the voltages of 5V and ?5V to a memory cell array, a 5 V voltage level detection circuit detecting the voltage derived from the voltage supply circuit, and a ?5 V voltage level detection circuit detecting the voltage derived from the voltage polarity inversion circuit. Absolute values of the voltages detected by the voltage level detection circuits are lower than ever before. This allows a gate insulation film to be thinner. A memory-function film is formed on both sides of a gate electrode in the semiconductor storage device. This also make the gate insulation film thinner. The thin gate insulation film suppresses the short-channel effect, so that each memory element of the memory cell array is miniaturized.

Abstract: The present invention provides a semiconductor storage device having: a first conductivity type region formed in a semiconductor layer; a second conductivity type region formed in the semiconductor layer in contact with the first conductivity type region; a memory functional element disposed on the semiconductor layer across the boundary of the first and second conductivity type regions; and an electrode provided in contact with the memory functional element and on the first conductivity type region via an insulation film, and a portable electronic apparatus comprising the semiconductor storage device. The present invention can fully cope with scale-down and high-integration by constituting a selectable memory cell substantially of one device.

Abstract: A semiconductor memory device including: a memory cell array in which memory cells are arranged; a plurality of terminals for accepting commands issued by an external user; a command interface circuit for interfacing between the external user and the memory cell array; a write state machine for controlling the programming and erasing operations; and an output circuit for outputting an internal signal to the plurality of terminals, wherein the memory cell includes a gate electrode formed over a semiconductor layer via a gate insulating film, a channel region disposed below the gate electrode, diffusion regions disposed on both sides of the channel region and having a conductive type opposite to that of the channel region, and memory functional elements formed on both sides of the gate electrode and having the function of retaining charges.

Abstract: A semiconductor storage device includes a memory cell array 21 in which a plurality of memory elements are arranged and a program verify circuit 30. The memory element 1, 33 includes a gate electrode 104 formed on a semiconductor layer 102 via a gate insulator 103, a channel region arranged below the gate electrode 104, diffusion regions 107a, 107b that are located on opposite sides of the channel region and have a conductive type opposite to that of the channel region, and memory function bodies 109 that are located on opposite sides of the gate electrode 104 and have a function of retaining electric charge. A program load register 32 of the program verify circuit 30 eliminates a state that a memory element 33 which has initially been verified as having been correctly programmed needs to be further programmed.

Abstract: A semiconductor memory device includes a control logic circuit for generating read selection signals each selecting one plane for reading and write selection signals each selecting one plane for writing from a plurality of planes in which memory cells are arranged in an array, an address selection circuit disposed for each of the planes, and an address buffer circuit for simultaneously providing a write address and a read address. Each of the address selection circuits is configured so as to be able to receive one of the read selection signals and one of the write selection signals from the control logic circuit.

Abstract: Characteristic fluctuation of a reference cell due to read disturb is prevented. A memory cell 27m and a reference cell 27r respectively have memory function bodies that are formed on both sides of a gate electrode and have a function to retain electric charge or polarization. The memory cell 27m can store independent information pieces in memory function bodies 27mr and 27ml located on both sides of the gate electrode and the independent information pieces are read therefrom. On the other hand, in the reference cell 27r, only the information piece stored in a memory function body 27rl located on one side of the gate electrode is referred to in a sense amplifier 22.

Abstract: A semiconductor storage device is provided with a gate electrode, a semiconductor layer, a gate insulating film sandwiched between the gate electrode and the semiconductor layer, a channel region under the gate electrode, diffusion regions provided respectively on two sides of the channel regions and being of the other conductivity region than the channel region, memory elements 1 provided respectively on two sides of the gate electrode and having a function of holding charges, and a word line driver circuit, in which the CMOS technique is used. The driver circuit includes a common node for supplying a potential for activating an output inverter for driving a row word line. While the semiconductor storage device is in a read mode, a CMOS inverter other than the output inverter controls a signal at the common node, the CMOS inverter connected to a read input line.

Abstract: A method of verifying programming of a nonvolatile memory cell to a desired state, the method comprising the steps of: selecting first and second references respectively corresponding to first and second voltages; applying a programming voltage to the memory cell; sensing a threshold voltage level of the memory cell; and comparing the sensed threshold voltage level with the first and second references and, in the case where the threshold voltage level is higher than the first reference and lower than the second reference, indicating that the memory cell is programmed into the desired state, wherein the nonvolatile memory cell includes a gate electrode formed on a semiconductor layer via a gate insulating film, a channel region formed below the gate electrode, a source and a drain as diffusion regions formed on both sides of the channel region and having a conductive type opposite to that of the channel region, and memory functional units formed on both sides of the gate electrode and having the function of re

Abstract: A method for driving a semiconductor memory device includes a memory array having a plurality of memory cells arranged in rows and columns. Each memory cell includes a gate electrode formed on a semiconductor layer via a gate insulating film, a channel region disposed below the gate electrode, a source and a drain as diffusion regions disposed on both sides of the channel region and having a conductive type opposite to that of the channel region, and memory functional units formed on both sides of the gate electrode and having a function of retaining charges. The method includes the steps of: selecting a row line connected to the gate electrode of a memory cell to be selected; grounding a first column line connected to the source of the memory cell to be selected; and applying a first potential to a second column line and a second potential to a third column line at the same time.