Author's Latest Posts


Ruthenium Interconnects On Tap


Chipmakers' focus on new interconnect technology is ramping up as copper's effectiveness continues to diminish, setting the stage for a significant shift that could improve performance and reduce heat at future nodes and in advanced packages. The introduction of copper interconnects in 1997 upended the then-standard tungsten via/aluminum line metallization scheme. Dual damascene integration ... » read more

Sidestepping Lithography In Chip Manufacturing


Rising lithography costs, shrinking feature sizes, and the need for an alternative to copper are collectively spurring new interest in area-selective deposition. An extension of atomic layer deposition, ASD seeks to build circuit features from the bottom up, without relying on lithography. Lithography will remain a critical tool for the foreseeable future. But it has long been the most expen... » read more

Enabling Advanced Devices With Atomic Layer Processes


Atomic layer deposition (ALD) used to be considered too slow to be of practical use in semiconductor manufacturing, but it has emerged as a critical tool for both transistor and interconnect fabrication at the most advanced nodes. ALD can be speeded up somewhat, but the real shift is the rising value of precise composition and thickness control at the most advanced nodes, which makes the ext... » read more

Powering CFETs From The Backside


The first CMOS circuits to incorporate backside power connections are likely to be based on stacked nanosheet transistors, but further down the road, planners envision complementary transistors (CFETs) that vertically integrate stacked NFET and PFET devices. With at least twice the thickness of a nanosheet transistor, connecting CFETs to each other and to the rest of the circuit is likely to... » read more

Building CFETs With Monolithic And Sequential 3D


Successive versions of vertical transistors are emerging as the likely successor to finFETs, combining lower leakage with significant area reduction. A stacked nanosheet transistor, introduced at N3, uses multiple channel layers to maintain the overall channel length and necessary drive current while continuing to reduce the standard cell footprint. The follow-on technology, the CFET, pushes... » read more

3D Integration Supports CIM Versatility And Accuracy


Compute-in-memory (CIM) is gaining attention due to its efficiency in limiting the movement of massive volumes of data, but it's not perfect. CIM modules can help reduce the cost of computation for AI workloads, and they can learn from the highly efficient approaches taken by biological brains. When it comes to versatility, scalability, and accuracy, however, significant tradeoffs are requir... » read more

Modeling Compute In Memory With Biological Efficiency


The growing popularity of generative AI, which uses natural language to help users make sense of unstructured data, is forcing sweeping changes in how compute resources are designed and deployed. In a panel discussion on artificial intelligence at last week’s IEEE Electron Device Meeting, IBM’s Nicole Saulnier described it as a major breakthrough that should allow AI tools to assist huma... » read more

Increasing AI Energy Efficiency With Compute In Memory


Skyrocketing AI compute workloads and fixed power budgets are forcing chip and system architects to take a much harder look at compute in memory (CIM), which until recently was considered little more than a science project. CIM solves two problems. First, it takes more energy to move data back and forth between memory and processor than to actually process it. And second, there is so much da... » read more

Ferroelectric Memories Answer Call For Non-Volatile Alternatives


As system designers seek to manipulate larger data sets while reducing power consumption, ferroelectric memory may be part of the solution. It offers an intermediate step between the speed of DRAM and the stability of flash memory. Changing the polarization of ferroelectric domains is extremely fast, and the polarization remains stable without power for years, if not decades. FeFETs, one of ... » read more

Is Maskless Lithography Coming Into Its Own?


Lithographers have always faced tradeoffs between speed and flexibility. Steppers are very good at printing hundreds or thousands of identical features onto hundreds or thousands of wafers. They are not especially good at handling surfaces with significant topography, though. Nor is customization feasible. Every exposure uses the same reticle. Direct write e-beam lithography has long been us... » read more

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