Infineon Technologies Ag

Kabushiki Kaisha Toshiba

Other

Michael Jacob

Thomas Roehr

Joerg W Wohlfahrt

Norbert Rehm

Daisaburo Takashima

Hans-Oliver Joachim

Ryu Ogiwara

Nobert Rehm

Thomas R&ouml;hr

Andreas Hilliger

Uwe Wellhausen

Toru Ozaki

Takashima Daisaburo

Susumo Shuto

Memory reliability is improved by using redundancy to repair errors detected by ECC. In one embodiment, redundancy repairs errors which cannot be corrected by ECC. The redundancy can employ the use of electronic fuses, enabling repairs after an IC containing the memory is packaged. Redundancy can also be performed prior to packaging of the IC.

Reducing memory failures in integrated circuits

A semiconductor device comprises a memory cell array, bit line, /bit line complementary to the bit line, reference voltage generating circuit and sense amplifier. The bit line is connected to the memory cells and applied with a voltage read from each memory cell of the memory cell array. The /bit line is supplied with a reference voltage. The reference voltage generating circuit generates the reference voltage that has temperature dependence for compensating a change in the voltage, read to the bit line, due to temperature. The reference voltage generating circuit controls the reference voltage such that the reference voltage assumes a midpoint of trails of a signal value distribution indicative of '0' data and a signal value distribution indicative of '1' data. The sense amplifier compares the voltage, read to the bit line, with the reference voltage supplied to the /bit line, and amplifies the difference therebetween.

Semiconductor device having semiconductor memory with sense amplifier

A memory cell signal window testing apparatusand method for testing the signal window of a memory are disclosed. First data is written to a memory cell during a write cycle. A low cell signal is read from the memory cell during a first read cycle. A comparison is made between the low signal and a low reference signal. The result of the comparison is stored in a first storage register. Second data is then written to the memory cell during a write cycle. A high cell signal is read from the memory cell during a second read cycle. A comparison is made between the high cell signal and a high reference signal. The result of the comparison is stored in a second storage register. The results in the first and second storage registers are compared and an output is provided indicating that the memory cell has failed the test if the comparison shows that both the low cell signal is higher than the low reference signal and the high cell signal is lower than the high reference signal.

Memory cell signal window testing apparatus

A ferroelectric memory array includes a plurality of memory pages each formed of a plurality of ferroelectric memory cells. The ferroelectric memory cells are supplied by common word lines. Status memory cells are connected to each of the plurality of memory pages, each status memory cell stores the status of the memory page to which it is connected. A plurality of sense amplifiers each receives inputs from a pair of bit lines. Each of the bit lines receives inputs from the ferroelectric memory cells of a plurality of the memory pages. The sense amplifiers write back data into the memory cells and status cells in reversed states following read operations.

Imprint suppression circuit scheme

A method for reducing noise coupling in a memory array is disclosed. The memory array includes a plurality memory cells interconnected by wordlines, bitlines, and platelines. The memory cells are arranged in columns having first and second bitlines coupled to a sense amplifier. During a memory access, at least adjacent bitlines pairs are not activated. The selected bitline pair or pairs are provided with a plateline pulse.

Reducing effects of noise coupling in integrated circuits with memory arrays

A test circuit for testing differential read signals during a memory access is disclosed. The test circuit is coupled to a pair of bit lines. During a read access, a selected memory cell produces a differential read signal on the bit lines. When the test circuit is activated, the magnitude of the differential read signal is varied. This enables easy testing of read signal margins in, for example, memory ICs.

Sensing test circuit

The present invention provides a test mode section for facilitating a worst case product test sequence for signal margin to ensure full product functionality over the entire component lifetime taking all aging effects into account. A semiconductor memory test mode configuration includes a first capacitor for storing digital data and connecting a cell plate line to a first bit line through a first select transistor. The first select transistor activated through a connection to a word line. A second capacitor stores digital data and connects the cell plate line to a second bit line through a second select transistor. The second select transistor is activated through a connection to the word line. A sense amplifier is connected to the first and second bit lines and measures a differential read signal on the first and second bit lines. A third transistor transfers charge between the first and second bit lines third to reduce the differential read signal.

2T2C signal margin test mode using a defined charge exchange between BL and/BL

An IC with memory cells arranged in a chained architecture is disclosed. The top local interconnect between the top capacitor electrodes and active area is achieved by using a strap. The use of a strap eliminates the need for additional metal layer which reduces manufacturing costs. Furthermore, sidewall spacers are used to isolate the strap from the different layers of the capacitors. The use of spacers advantageously enables the strap to be self-aligned.

Ferroelectric memory integrated circuit with improved reliability

An improved memory IC whose memory cells are configured in a chain architecture is disclosed. The first diffusion regions of the cell transistors of the chain are coupled to first capacitor electrodes while the second diffusion regions are coupled to second capacitor electrodes. This ensures that the electric field applied across any of the capacitors of the chain by a plateline pulse is in the same direction. This reduces or avoids asymmetrical hysteresis curves for adjacent memory cells, thereby the improving sensing window.

Memory integrated circuit

The present invention provides a test mode section for facilitating a worst case product test sequence for signal margin to ensure full product functionality over the entire component lifetime taking all aging effects into account. A semiconductor memory test mode configuration includes a first capacitor for storing digital data connecting a cell plate line to a first bit line through a first select transistor. The first select transistor is activated through a connection to a word line. A second capacitor stores digital data and connects the cell plate line to a second bit line through a second select transistor. The second select transistor is activated through a connection to the word line. A sense amplifier is connected to the first and second bit lines for measuring a differential read signal on the first and second bit lines A resistor is connected to one or both of the bit lines through transistors for adding or reducing the amount of charge on the first bit line when the third transistor is turned on to reduce the differential read signal.

2T2C signal margin test mode using resistive element

A memory chain with capacitors having different capacitances, depending on the location of the memory cell within the chain, is described. Varying the capacitances of the capacitors advantageously enables an effective capacitance for all memory cells within the chain to be about the same.

Variable capacitances for memory cells within a cell group

An improved cell design for series memory architecture is disclosed. The improved cell design facilitates the formation of capacitors using a single etch process instead of two, as conventionally required. In one embodiment, each capacitor of a capacitor pair is provided with at least one plug contacting a common diffusion region of two adjacent cell transistors. In another embodiment, a large plug with sufficient overlap to the bottom electrodes of pair of capacitors is used.

Memory architecture with memory cell groups

A test circuit is integrated in a ferroelectric memory component in order to make analog measurements of bit line signals of ferroelectric memory cells. The test circuit, when in a test mode, reads out analog signal values for the respective memory content of the cells and feds the analog signal values to a downstream evaluation device. The test circuit is integrated as an analog circuit in the ferroelectric memory component and, in the test mode with non-activated or disconnected sense amplifiers, is configured to output analog bit line signals from the memory component to a point outside the memory component.

Test circuit for an analog measurement of bit line signals of ferroelectric memory cells

The present invention describes an information recorder which is integrated into an IC, such as ferroelectric RAM device. The recorder counts desired events, such as memory accesses or length of time powered up and stores such information in a latch. The information can be retrieved from the latch to assist in failure analysis and device characterization.

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Yokohama, Japan

Michael Jacob