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Imaging Of Overlay And Alignment Markers Under Opaque Layers Using Picosecond Laser Acoustic Measurements


Optically opaque materials present a series of challenges for alignment and overlay in the semi-damascene process flow or after the processing of the magnetic tunnel junction (MTJ) of a Magnetic Random-Access Memory (MRAM). The overlay and alignment of a lithographically defined pattern on top of the pattern and the underlying layer is fundamental to device operation in all multi-layer patterne... » read more

Reliable And Efficient Compact Models For Scalable MTJ Simulation


By Fernando García Redondo, Pranay Prabhat, and Mudit Bhargava Since its discovery in 1975, Tunnel-Magneto-Resistance (TMR) has been actively investigated. From the 2000s, advances in process technologies have made the miniaturization of Magnetic Random Access Memories (MRAMs) based on TMR devices possible, together with integration into traditional CMOS processes. Introducing magneti... » read more

New Memories Add New Faults


New non-volatile memories (NVM) bring new opportunities for changing how we use memory in systems-on-chip (SoCs), but they also add new challenges for making sure they will work as expected. These new memory types – primarily MRAM and ReRAM – rely on unique physical phenomena for storing data. That means that new test sequences and fault models may be needed before they can be released t... » read more

A Compact Model For Scalable MTJ Simulation


Read the full technical paper. Published June 9, 2021. Abstract This paper presents a physics-based modeling framework for the analysis and transient simulation of circuits containing Spin-Transfer Torque (STT) Magnetic Tunnel Junction (MTJ) devices. The framework provides the tools to analyze the stochastic behavior of MTJs and to generate Verilog-A compact models for their simulation in lar... » read more

MRAM Evolves In Multiple Directions


Magnetoresistive RAM (MRAM) is one of several new non-volatile memory technologies targeting broad commercial availability, but designing MRAM into chips and systems isn't as simple as adding other types of memory. MRAM isn’t an all-things-for-all-applications technology. It needs to be tuned for its intended purpose. MRAMs targeting flash will not do as well targeting SRAMs, and vice vers... » read more

Testing Embedded MRAM IP For SoCs


The challenges of embedded memory test and repair are well known, including maximizing fault coverage to prevent test escapes and using spare elements to maximize manufacturing yield. With the surge in availability of promising non-volatile memory architectures to augment and potentially replace traditional volatile memories, a new set of SoC level memory test and repair challenges are emerging... » read more

MRAM Process Development And Production Briefing


By Dr. Meng Zhu, Dr. Roman Sappey, and Jeff Barnum MRAM (Magnetoresistive Random-Access Memory) is a type of non-volatile memory (NVM) that utilizes magnetic states to store information. The basic structure of MRAM is a magnetic-tunnel junction (MTJ), which consists of two ferromagnetic (FM) layers separated by an insulating tunnel barrier (Fig.1). When the magnetizations of the two magnetic... » read more

Taming Novel NVM Non-Determinism


New memory technologies may have non-deterministic characteristics that add calibration to the test burden — and may require recalibration during their lifetime. Many of these memories are in development as a result of the search for a storage-class memory (SCM) technology that can bridge the gap between larger, slower memories like flash and faster DRAM memory. There are several approache... » read more

New Embedded Memories Ahead


The embedded memory market is beginning to heat up, fueled by a new wave of microcontrollers (MCUs) and related chips that will likely require new and more capable nonvolatile memory types. The industry is moving on several different fronts in the embedded memory landscape. On one front, traditional solutions are advancing. On another front, several vendors are positioning the next-generatio... » read more