Texas Instruments Corporation

University of Florida Research Foundation, Incorporated

John Anthony Rodriguez

Richard Allen Bailey

Scott Robert Summerfelt

Steven Craig Bartling

Carl Z Zhou

Hugh Pryor McAdams

Kezhakkedath Ramunni Udayakumar

Robert Christopher Baumann

Keith A Remack

Huang-Chun Wen

Bhaskar Srinivasan

Archana Venugopal

Vijay Kumar Reddy

Susan Trolier-McKinstry

Michael Allen Ball

Sunil Kumar Dusa

Boku Katsushi

Antonio Guillermo Acosta

Carl Sebastian Morandi

John Lane Gertas

Michael C Smayling

Sanjeev Aggarwal

Theodore Sidney Moise

Shan Sun

Eric Thierry Peeters

Toshikazu Nishida

Anand T Krishnan

Kemal Tamer San

Jihong Chen

K R Udayakumar

P R Chidambaram

William Francis Kraus

Alister C Young

Manuel Gilberto Aguilar

In some examples, a system comprises a capacitor including a first plate, a second plate, and a ferroelectric material disposed between the first and the second plates and comprising a Bismuth Metal Oxide-Based Lead Titanate thin film. The capacitor further comprises a dielectric layer disposed on a transistor, wherein the capacitor is disposed on the dielectric layer.

Capacitor comprising a bismuth metal oxide-based lead titanate thin film

Curing of a passivation layer applied to the surface of a ferroelectric integrated circuit so as to enhance the polarization characteristics of the ferroelectric structures. A passivation layer, such as a polyimide, is applied to the surface of the ferroelectric integrated circuit after fabrication of the active devices. The passivation layer is cured by exposure to a high temperature, below the Curie temperature of the ferroelectric material, for a short duration such as on the order of ten minutes. Variable frequency microwave energy may be used to effect such curing. The cured passivation layer attains a tensile stress state, and as a result imparts a compressive stress upon the underlying ferroelectric material. Polarization may be further enhanced by polarizing the ferroelectric material prior to the cure process.

Low-temperature passivation of ferroelectric integrated circuits for enhanced polarization performance

Disclosed embodiments include a testing system that electrically connects to an integrated circuit (IC) having ferroelectric memory (FRAM) cells. The testing system programs the FRAM cells to a first data state and then iteratively reads the programmed cells at a plurality of reference voltages to identify a reference voltage limit that indicates a first occurrence at which at least one of the cells fails to return the first data state when read. Iteratively reading the cells includes reading each cell at an initial reference voltage at which all the cells return the first data state, and then reading each of the programmed cells at each of the remaining reference voltages by incrementally changing the initial reference voltage in one direction until the reference voltage limit is identified. The testing system sets the reference in the IC at an operating level based on the reference voltage limit.

Setting of reference voltage for data sensing in ferroelectric memories

A system includes a ferroelectric random access memory (FRAM) array having one or more memory elements. A cycle controller cycles data to be fixed in a subset of the one or more memory elements by reading or writing the data a predetermined number of times to fix the data to a non-volatile stable state.

Method and circuit enabling ferroelectric memory to be fixed to a stable state

A method of generating a random number from an electronic circuit memory and/or a system with the electronic circuit memory. The memory comprises a block of ferroelectric two transistor, two capacitor (2T-2C), memory cells. The method comprises: (i) first, writing a predetermined programming pattern to the block cells in a one transistor, one-capacitor (1T-1C) mode, thusly writing, per cell, a same data state to both a first and second sub-cell of the cell; (ii) second, reading the cells in a 2T-2C mode to generate a random number comprising a random bit from each of the cells; (iii) third, restoring the random number into the cells in a 2T-2C mode, thusly writing, per cell, a complementary data state to both a first and second sub-cell of the cell, responsive to a respective random number bit; and fourth, imprinting the random number in each cell in the block.

Physical unclonable function system and method

A data retention reliability screen of integrated circuits including ferroelectric random access memory (FRAM) arrays. Sampled groups of cells in the FRAM array are tested at various reference voltage levels, after programming to a high polarization capacitance data state and a relaxation time at an elevated temperature. Fail bit counts of the sample groups at the various reference voltage levels are used to derive a test reference voltage, against which all of the FRAM cells in the integrated circuit are then tested after preconditioning (i.e., programming) and another relaxation interval at the elevated temperature, to determine those cells in the integrated circuit that are vulnerable to long-term data retention failure.

Screening for data retention loss in ferroelectric memories

A system on chip (SoC) may include a nonvolatile ferroelectric random access memory (FRAM). A random number may be created by applying operating power to the ferroelectric random access memory (FRAM) device and reading a sequence of virgin memory locations within the FRAM device to produce the random number sequence. The sequence of virgin memory locations had previously never been written. The random number may be produced during an initial boot of the SoC, for example. Alternatively, the random number may be saved by a test station during testing of the FRAM device after fabrication of the FRAM device. A memory test of the FRAM may then be performed, after which the random number may be stored in a defined location in the FRAM.

Random number generation with ferroelectric random access memory

A fuse-programmable register or memory location having a plurality of fusible links of differing electrical characteristics in parallel. In one embodiment, three fusible links with different resistances are provided, such that application of a programming voltage non-uniformly distributes the current among the links, allowing varying voltages to selectively blow one or more of the links. Sensing of the programmed state is performed by applying a voltage across the parallel links and measuring the current in comparison with a plurality of reference currents. Reduction in the overhead chip area per bit and in the serial data communication latency are obtained.

Fusible link cell with dual bit storage

Disclosed embodiments relate to generating random numbers using two transistor, two capacitor (2T-2C) ferroelectric memory cells. In accordance with one disclosed embodiment, an n-bit random number can be generated by writing to a uniform data pattern to a set of n 2T-2C ferroelectric memory cells in a 1T-1C mode so that all ferroelectric capacitors of the n 2T-2C cells have a polarization state corresponding to the same data value (e.g., all 0's or all 1's). The n 2T-2C cells are then read in a 2T-2C mode, so that a random bit (a 0 or 1) is produced for each cell, resulting in an n-bit random number. The n-bit random number is stored in the n 2T-2C ferroelectric memory cells by a rewrite operation. Such random numbers are useful for many purposes, including security, such as authentication, integrity checking, and encryption, and for identification.

Random number generation in ferroelectric random access memory (FRAM)

Disclosed embodiments relate to generating random numbers using two transistor, two capacitor (2T-2C) ferroelectric memory cells. In accordance with one disclosed embodiment, an n-bit random number can be generated by writing to a uniform data pattern to a set of n 2T-2C ferroelectric memory cells in a 1T-1C mode so that all ferroelectric capacitors of the n 2T-2C cells have a polarization state corresponding to the same data value (e.g., all 0's or all l's). The n 2T-2C cells are then read in a 2T-2C mode, so that a random bit (a 0 or 1) is produced for each cell, resulting in an n-bit random number. The n-bit random number is stored in the n 2T-2C ferroelectric memory cells by a rewrite operation. Such random numbers are useful for many purposes, including security, such as authentication, integrity checking, and encryption, and for identification.

A method of setting the reference voltage for sensing data states in integrated circuits including ferroelectric random access memory (FRAM) cells of the one-transistor-one capacitor (1T-1C) type. In an electrical test operation, some or all of the FRAM cells are programmed to a particular polarization state. A 'shmoo' of the reference voltage for sensing the data state is performed, at one or more worst case electrical or environmental conditions for that data state, to determine a reference voltage limit at which the weakest cell fails to return the correct data when read. A configuration register is then written with a reference voltage based on this reference voltage limit, for example at the limit plus/minus a tolerance.

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John Anthony Rodriguez