摘要:
A ferroelectric memory having a memory cell array or a plurality of memory cell arrays, word lines, where each memory cell array includes word lines. The memory also includes a plurality of plate lines, where each memory cell array includes some of the plate lines and the word line corresponds with some of the plate lines, a bit line, a word line select circuit for selecting among the word lines, and plurality of plate line select circuits, where each of the plate line select circuit is coupled to an associated plate line.
摘要:
A ferroelectric memory has a memory cell screening test circuit connected to bit lines through switching transistors. In screening, at least one word line is selected, and data is simultaneously written in all memory cells connected to this word line. Since data is not restored after the rewrite, all FRAM cells can be screened under the same condition. By this circuit, a memory cell having a write failure according to the imprint characteristics inherent to the ferroelectric memory is screened.
摘要:
A nonvolatile ferroelectric memory comprises a memory cell array having memory cells arranged as a matrix array and each including a charge transfer transistor having a source or drain region connected to a bit line and a gate connected to a word line and a ferroelectric capacitor for information storage having one electrode connected to a plate line and the other electrode connected to the drain or source region of the charge transfer transistor. A first dummy line is arranged outside a bit line formed at an end of the memory cell array and second dummy bit lines are arranged between the bit line at the end of the memory cell array and the first dummy bit line. Dummy memory cells are connected to the second dummy bit line and have the same in configuration and size as the memory cells connected to the bit line.
摘要:
Circuitry within a ferroelectric memory prevents inversion of the polarization of ferroelectric memory cells caused by a power on reset signal to avoid corruption of data stored therein. A ferroelectric memory includes a memory cell array, a plurality of word lines commonly connected to the gates of the cell transistors in the same row, a plurality of plate lines commonly connected to the plates of the cell capacitors in the same row, a plurality of bit lines commonly connected to one end of the cell transistors in the same row, and a power on reset circuit for generating a power on reset signal of a predetermined level for a predetermined period of time after the power supply is turned on. An erroneous programming prevention circuit within the memory includes a plurality of switching transistors connected between all of the bit lines and plate lines and a plurality of nodes at a predetermined potential. The switching transistors are controlled by the power on reset signal so that they are on for a predetermined period of time.
摘要:
Circuitry within a ferroelectric memory prevents inversion of the polarization of ferroelectric memory cells caused by a power on reset signal to avoid corruption of data stored therein. A ferroelectric memory includes a memory cell array, a plurality of word lines commonly connected to the gates of the cell transistors in the same row, a plurality of plate lines commonly connected to the plates of the cell capacitors in the same row, a plurality of bit lines commonly connected to one end of the cell transistors in the same row, and a power on reset circuit for generating a power on reset signal of a predetermined level for a predetermined period of time after the power supply is turned on. An erroneous programming prevention circuit within the memory includes a plurality of switching transistors connected between all of the bit lines and plate lines and a plurality of nodes at a predetermined potential. The switching transistors are controlled by the power on reset signal so that they are on for a predetermined period of time.
摘要:
A chain type ferroelectric random access memory has a memory cell unit including ferroelectric memory cells electrically connected in series to each other, a plate line connected to an electrode of the memory cell unit, a bit line connected to the other electrode of the memory cell unit via a switching transistor, a sense amplifier which amplifies the voltages of this bit line and its complementary bit line, and a transistor inserted between the switching transistor and the sense amplifier. A value, being the minimum value of the gate voltage in the transistor obtained during elevation of the plate line voltage and comparative amplification, is smaller than a value, being the maximum value of the gate voltage in the transistor obtained during fall of the plate line voltage and comparative amplification. With these features, decrease in the accumulated charge of polarization in the memory cell is reduced and occurrence of disturb is prevented during read/write operations.
摘要:
A nonvolatile semiconductor memory device is provided in which a negative voltage is applied to a gate electrode of a memory cell transistor during an erase mode. The memory device includes a row decoder circuit having an N-channel transistor connected to a word line. The N-channel transistor is provided on a P-type well region of a semiconductor substrate. A negative voltage is applied to the P-type well region during the erase mode, while ground potential is applied thereto during another modes.
摘要:
A dummy cell is provided in every column and consists of a dummy capacitor and two transistors. When the charge of the ferroelectric capacitor is released to one of a bit line pair, a first dummy word line is selected and charge of the dummy capacitor is released to the other of the bit line pair by way of one of the two transistors. When the charge of the ferroelectric capacitor is released to the other of the bit line pair, a second dummy word line is selected and the charge of the dummy capacitor is released to one of the bit line pair by way of the other one of the two transistors. When either one of the first and second dummy word lines is selected the dummy plate driver supplies a clock signal to the dummy capacitor.
摘要:
In a flash memory EEPROM, a memory cell MC is formed in a P-type semiconductor substrate. A peripheral transistor TR is formed in an N-type well. Another peripheral transistor TR is formed in a P-type well. The P-type well is by turn formed an N-type well and electrically insulated from the substrate. The substrate is typically provided with a metal back structure and its substrate voltage is set to predetermined voltages respectively for data erasure, data storage and data retrieval. With such an arrangement, the level of voltage stress with which the device is loaded during data erasure can be remarkably reduced to allow a down-sizing and an enhanced quality to be realized for the device.
摘要:
A semiconductor non-volatile memory device having non-volatile memory cells for storing binary data, a plurality of column lines respectively connected to the plurality of memory cells and a plurality of row lines respectively connected to the plurality of memory cells comprising a plurality of dummy cells, having the same structure as the memory cells, respectively connected to the column lines and arranged to be set in an ON state upon being selected, a dummy row line connected to the plurality of dummy cells, a dummy row line selector for selecting the dummy row line for a predetermined period in response to a chip selection signal for selecting the memory device. Therefore, since the dummy row line is selected for the predetermined period before the memory device is selected by a computer system or the like, each of the column lines is set at a ground potential by a dummy memory cell set in an ON state. During a transition from the non-selected state to a selected state of the memory device, in synchronism with the transition from the non-selected state to the selected state of a target memory cell in a plurality of memory cells, the state of a dummy cell connected to the target memory cell transits from the selected state to the non-selected state.