摘要:
Method for conversion of a Flash memory cell on a first semiconductor device to a ROM memory cell in a second semiconductor device, the first and second semiconductor device each being arranged on a semiconductor substrate and each comprising an identical device portion and an identical wiring scheme for wiring the device portion to the Flash memory cell and to the ROM memory cell, respectively; the Flash memory cell being made in non-volatile memory technology and comprising an access transistor and a floating transistor, the floating transistor comprising a floating gate and a control gate; the ROM memory cell being made in a baseline technology and comprising a single gate transistor, which method includes manipulating a layout of at least one baseline mask as used in the baseline technology; the manipulation including: incorporating into the layout of the at least one baseline mask a layout of the Flash memory cell, and converting the layout of the Flash memory cell to a layout of one ROM memory cell by eliminating, from the at least one baseline mask, a layout for the floating transistor from the layout of the Flash memory cell and designating the layout of the access transistor of the Flash memory cell as a layout of the single gate transistor of the ROM memory cell.
摘要:
Method for conversion of a Flash memory cell on a first semiconductor device to a ROM memory cell in a second semiconductor device, the first and second semiconductor device each being arranged on a semiconductor substrate and each comprising an identical device portion and an identical wiring scheme for wiring the device portion to the Flash memory cell and to the ROM memory cell, respectively; the Flash memory cell being made in non-volatile memory technology and comprising an access transistor and a floating transistor, the floating transistor comprising a floating gate and a control gate; the ROM memory cell being made in a baseline technology and comprising a single gate transistor, which method includes manipulating a layout of at least one baseline mask as used in the baseline technology; the manipulation including: incorporating into the layout of the at least one baseline mask a layout of the Flash memory cell, and converting the layout of the Flash memory cell to a layout of one ROM memory cell by eliminating, from the at least one baseline mask, a layout for the floating transistor from the layout of the Flash memory cell and designating the layout of the access transistor of the Flash memory cell as a layout of the single gate transistor of the ROM memory cell.
摘要:
The invention relates in particular, though not exclusively, to an integrated circuit with an embedded non-volatile memory with floating gate (10). According to the invention, at least two poly layers of equal or at least substantially equal thickness are used for this device. The first poly layer, poly A, is for the floating gate (10) and for the gates (22) of NMOS and PMOS in the logic portion of the circuit. The second poly layer, poly B, serves exclusively for the control electrode (21) above the floating gate. If so desired, a third poly layer may be deposited for both the control electrode and the logic gates, so that the thicknesses of these electrodes, and thus their resistances, are given desired values. Problems like overetching and bridging during saliciding are prevented in that the control electrode and the logic gates have the same thickness.
摘要:
An MRAM memory is proposed which gives a maximum read-out signal. This is advantageous for high-speed sensing of the MRAM bits. In an MRAM memory with magnetoresistive memory cells linked together to form logically organized rows and columns, It is obtained by, at least during writing, connecting write bitlines of two adjacent rows or columns with each other, so as to write inverse data values in two adjacent memory cells. In this way, a return path for the writing current is provided in a small loop, which enhances EMC behavior.
摘要:
In programmable memories of the EPROM or EEPROM type, a row and/or column of test memory cells are added to the matrix of rows and columns of non-volatile memory cells for the testing of the peripheral circuits which select and read the memory cells. The test memory cells have a very short write time as compared with the non-volatile memory cells and may be of the dynamic (or volatile) type. The write time for a memory cell of the EPROM or EEPROM may be, for example, 10 msec. The write time for a dynamic memory cell, however, is 100 nsec. The time required for testing the peripheral circuits can therefore be reduced by a factor of 80 (for a 16 Kbit memory) or higher (for memories larger than 16 Kbits).
摘要:
Field effect transistors having a short channel length are desirable for carrying out logic operations at a high speed. However, they are then not capable of withstanding the comparatively high programming and erasing voltage at which an (E)EPROM has to be operated. During the programming cycle the field effect transistors are kept in the current-nonconducting state, while recording the logic information obtained by the logic operations, the "fast" transistors are nevertheless capable of withstanding the comparatively high voltage.
摘要:
The present invention provides a method and device for programming a magnetic random access memory element with reduced current consumption, by re-routing digitline current through a selected bitline in a selected direction.
摘要:
The present invention describes a matrix with magnetoresistive memory cells arranged in logically organized rows and columns, Each memory cell includes a magnetoresistive element. The matrix comprises means for simultaneously reading from one cell in a column and writing to another cell in a column, or means for simultaneous reading from one cell in a row and writing to another cell in the same row. Such matrix can be used in a read-while-write MRAM memory.
摘要:
The invention relates to a non-volatile memory with floating gate, in particular a Flash-EPROM, in which writing takes place through injection of hot electrons into the floating gate and in which erasing takes place through injection of hot holes. To keep the write and erase voltages sufficiently low, p-type zones which locally increase the background doping concentration of the p-type substrate are provided around the n-type source and drain zones. These p-type zones cause an increased field strength at the drain zone whereby hot electrons are formed at the pinch-off point also at lower voltages. This increased background concentration in addition reduces the breakdown voltage of the pn junction of the source and drain zones, so that hot holes for erasing can be formed by pn breakdown at comparatively low voltages. The device is particularly suitable for being integrated into a signal processing IC manufactured in a standard process, such as a microcontroller.
摘要:
Each memory cell of an electrically-programmable semiconductor memory has a field-effect transistor with a charge-storage region. Efficient and fast injection of hot carriers into the charge-storage region is achieved by vertical punch-through of a depletion layer to a buried injector region, by application of programming voltages to a control gate and to the surface of the punch-through region. Non-injected carriers are removed via at least the transistor drain during the programming. A well-defined punch-through region can be obtained with a higher-doped boundary region at at least one side of the punch-through region to restrict the lateral spread of the depletion layer(s) and prevent parasitic connections. This permits closer spacing of the injector region to other regions of the memory cell, e.g. source and drain regions, and the injector region may adjoin an inset insulating field pattern. A compact cell array layout can be formed with a common connection region for the injector regions of two adjacent cells and for either a source or drain region of four other adjacent cells. The control gate and an erase gate may both be coupled in the same manner to the charge-storage region, and the cell can be operated with complementary voltage levels for writing and erasing. A feed-back mechanism with the start of injection from the punch-through and injector regions can provide a well-defined charge level limit for the erasure.