摘要:
The semiconductor memory device of the invention includes at least three memory cell blocks arranged in a word line direction. Each of the memory cell blocks includes a plurality of memory cells arranged in a bit line direction. Each of the memory cells includes a ferroelectric capacitor for storing data by displacement of polarization of a ferroelectric film and a selection transistor connected to one of paired electrodes of the ferroelectric capacitor. Each of the memory cell blocks also includes: a bit line, a sub-bit line and a source line extending in the bit line direction; and a read transistor having a gate connected to one end of the sub-bit line, a source connected to the source line, and a drain connected to one end of the bit line. The read transistor reads data by detecting the displacement of the polarization of the ferroelectric film of the ferroelectric capacitor of a data read memory cell from which data is read among the plurality of memory cells. The sub-bit lines of any two of the memory cell blocks are connected to each other via a sub-bit line coupling switch.
摘要:
In a ferroelectric capacitor, two displacements (points b and c) of a remanent polarization correspond to data “1” and one displacement (point a) of the remanent polarization corresponds to data “0”. When the data “1” is written, either of two electric voltage pulses different in potential or in pulse width is applied to the ferroelectric capacitor to position the displacement of the remanent polarization in the ferroelectric capacitor at the point b or at the point c. When the data “0” is written, on the other hand, the displacement of the remanent polarization in the ferroelectric capacitor is positioned at the point a.
摘要:
A semiconductor memory device has a plurality of memory cells each having a first ferroelectric capacitor for storing data as a polarization value. First voltage applying means applies a first read voltage between the pair of electrodes of the first ferroelectric capacitor composing that one of the plurality of memory cells from which data is to be read. Data reading means detects the polarization value in the first ferroelectric capacitor when the first read voltage is applied between the pair of electrodes of the first ferroelectric capacitor and thereby reads the data stored in the first ferroelectric capacitor therefrom. A hysteresis loop in the first ferroelectric capacitor is shifted in a direction of voltage opposite in polarity to the first read voltage.
摘要:
A semiconductor memory includes a ferroelectric capacitor having a ferroelectric film, a first electrode formed on the ferroelectric film and a second electrode formed under the ferroelectric film. A data writing unit causes a first state in which the ferroelectric film has polarization in a direction from the first electrode to the second electrode or in a direction from the second electrode to the first electrode and has a substantially saturated polarization value or a second state in which the ferroelectric film has polarization in the same direction as in the first state and has a substantially zero polarization value, thereby writing a data corresponding to the first state or the second state in the ferroelectric capacitor. A data reading unit detects whether the ferroelectric capacitor is in the first state or in the second state, thereby reading a data stored in the ferroelectric capacitor.
摘要:
A semiconductor device of the present invention includes: at least one of non-volatile memory unit operable to store data; at least one of an arithmetic-logic unit operable to perform an arithmetic-logic operation using data which is stored in the memory unit and data that is inputted from outside; and an output unit operable to output a result of arithmetic-logic operation performed by the arithmetic-logic unit; wherein the memory unit, the arithmetic-logic unit, and the output unit are included in a functional block, and an output line of each of the memory unit is connected only to one of at least one of the arithmetic-logic unit.
摘要:
The power-supply unit, while directing externally supplied power to the control unit and the like, accumulates an amount of power that is required by the control unit to save data from the volatile memory to the non-volatile memory. When an external power supply has started, the control unit restores data of the non-volatile memory in the volatile memory; and when the external power supply has stopped, the control unit saves data from the volatile memory to the non-volatile memory.
摘要:
A semiconductor memory of this invention is composed of an MFMIS transistor including a first field effect transistor and a ferroelectric capacitor formed on or above the first field effect transistor with a gate electrode of the first field effect transistor working as or being electrically connected to a lower electrode of the ferroelectric capacitor, an upper electrode of the ferroelectric capacitor working as a control gate and the first field effect transistor having a first well region; and a second field effect transistor having a second well region that is isolated from the first well region of the first field effect transistor. The first well region of the first field effect transistor is electrically connected to the source region of the second field effect transistor, and the gate electrode of the first field effect transistor is electrically connected to the drain region of the second field effect transistor.
摘要:
A semiconductor memory includes a storing transistor for storing data, wherein the storing transistor includes an MFS transistor, an MFIS transistor, or an MFMIS transistor, and a selecting transistor for selecting the storing transistor. The storing transistor is a first field effect transistor having a first well region. The selecting transistor is second field effect transistor having a second well region that is isolated from the first well region of the first field effect transistor. The semiconductor memory further includes a first voltage supply line for supplying a DC voltage to the first well region of the first field effect transistor, and a second voltage supply line, independent of the first voltage supply line, for supplying a DC voltage to the second well region of the second field effect transistor.
摘要:
A multi-valued data is written in a ferroelectric capacitor, which stores a multi-valued data in accordance with displacement of polarization of a ferroelectric film thereof, by applying a relatively high first writing voltage or a relatively low second writing voltage between a first electrode and a second electrode of the ferroelectric capacitor. Next, a potential difference induced between the first and second electrodes is removed. Then, the multi-valued data is read by detecting the displacement of the polarization of the ferroelectric film by applying a reading voltage between the second electrode and a substrate where a reading FET for detecting the displacement of the polarization of the ferroelectric film is formed. The reading voltage has the same polarity as the first writing voltage and is set to such magnitude that, in applying the reading voltage, a first potential difference induced between the gate electrode of the reading FET and the substrate when the multi-valued data is written by applying the first writing voltage is smaller than a second potential difference induced between the gate electrode and the substrate when the multi-valued data is written by applying the second writing voltage.
摘要:
A ferroelectric memory 636 includes a group of memory cells (645, 12, 201, 301, 401, 501), each cell having a ferroelectric memory element (44, 218, etc.), a drive line (122, 322, 422, 522 etc.) on which a voltage for writing information to the group of memory cells is placed, a bit line (25, 49, 125, 325, 425, 525, etc.) on which information to be read out of the group of memory cells is placed, a preamplifier (20, 42, 120, 320, 420, etc.) between the memory cells and the bit line, a set switch (14, 114, 314, 414, 514, etc.) connected between the drive line and the memory cells, and a reset switch (16, 116, 316, 416, 516, etc.) connected to the memory cells in parallel with the preamplifier. The memory is read by placing a voltage less than the coercive voltage of the ferroelectric memory element across a memory element. Prior to reading, noise from the group of cells is discharged by grounding both electrodes of the ferroelectric memory element.