Infineon Technologies Ag

Other

Kabushiki Kaisha Toshiba

Hans-Oliver Joachim

Thomas Roehr

Joerg W Wohlfahrt

Norbert Rehm

Michael Jacob

Nobert Rehm

Takashima Daisaburo

Tadashi Miyakawa

Roehr Thomas

The present invention includes a ferro fuse cell comprising a ferroelectric storage capacitor electrically connected to a plate on one side and to a sense amplifier on the other side. A ferroelectric measurement capacitor is electrically connected between the ferroelectric storage capacitor and the sense amplifier.

Reliable ferro fuse cell

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

Improved sensing of ferroelectric memory cells is disclosed. When a memory access is initiated, the bitlines are precharged to a negative voltage, for example, &#x2212;0.5 to &#x2212;1.0V. This increases the effective plateline pulse (V) to V+the magnitude of the negative voltage. This results in an increase in the difference between Vand Vread signals, thereby increasing the sensing window.

Increasing the read signal in ferroelectric memories

A redundancy unit includes first and second fuse blocks for programming the redundancy element. One fuse block has laser blowable fuses and the other electrical fuses. The redundancy unit can be programmed by either one of the fuse blocks, enabling the redundancy unit to able to be used for defects identified before packaging and as well as after.

Hybrid fuses for redundancy

A memory IC having improved sensing during reads is disclosed. The IC includes the use of first and second reference voltages for sensing to compensate for asymmetry that exists between cells on bitline true and bitline complement. The first reference voltage is used for sensing a cell on bitline true while the second reference voltage is used for sensing a cell on bitline complement.

Sensing of memory integrated circuits

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 improved redundancy scheme for chained memory architecture is disclosed. The redundancy scheme comprises including redundant cells as part of the memory chain. As such, a redundant cell is used to repair a defective cell within the chain. This eliminates the need in conventional chained architecture to replace the whole memory block when there is a defective cell.

Redundancy in series grouped memory architecture

A semiconductor memory test mode configuration includes a first capacitor for storing digital data. The first capacitor connects a cell plate line to a first bit line through a first select transistor which is activated through a connection to a word line. A second capacitor for storing digital data connects the cell plate line to a second bit line through a second select transistor which is also 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 constant current mover, for example a constant current sink or source, is connected to the first bit line through a third transistor for changing 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 a defined charge and discharge of BL and /BL

A FeRAM memory chip comprises an array of non-volatile ferrocapacitor memory cells for storing data. Input pins receive data to be stored, and address data indicating where in the array of memory cells the data should be stored. The FeRAM memory chip further has a reset unit for recognizing an externally applied reset signal. The reset unit , upon recognition of the reset signal, initiates a reset operation in which at least a portion of the data stored in the memory cells is set to predetermined values.

FeRAM memory device

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.

Historical information storage for integrated circuits

An improved reference voltage generation is described. In one embodiment, a memory block includes a plurality of memory cells interconnected by wordlines and bitlines. A plurality of reference cells are provided. A bitline includes a reference cell. The bitlines of the memory block are divided into groups or bitlines. The reference cells within a group are interconnected to average out the reference cell charge variation to improve the sensing window.

Reference voltage generation for memory circuits

A chained memory IC in which a dual voltage scheme is used for operating the wordlines is described. During standby mode, the wordlines are maintained at a first logic 1 voltage level. To prepare for a memory access, the non-selected wordlines are driven to a boosted voltage while the selected wordline is driven to ground. The first logic 1 voltage level is less than the boosted voltage. This reduces the stress on the gate oxide of the transistors, thus improving reliability of the memory IC.

Growing community of inventors

Kanagawa-ken, Japan

Hans-Oliver Joachim