Content-addressable memory (CAM) and associative memory (AM) are types of storage structures that allow searching by content as opposed to searching by address. Such memory structures are used in diverse applications ranging from branch prediction in a processor to complex pattern recognition. In this paper, we review the emerging challenges and opportunities in implementing different varieties of CAM/AM structures. Beyond-CMOS silicon and nonsilicon memory technologies hold significant promise in implementing dense, fast, and energy-efficient CAM/AM structures. We describe circuit/architecture level implementations of CAM/AM using these technologies, as well as novel applications in different domains, including informatics, text analytics, data mining, and reconfigurable computing platforms.

Emerging Trends in Design and Applications of Memory-Based Computing and Content-Addressable Memories

Performance, scalability, and resilience to variability of Si SOI FinFETs and gate-all-around (GAA) nanowires (NWs) are studied using in-house-built 3-D simulation tools. Two experimentally based devices, a 25-nm gate length FinFET and a 22-nm GAA NW are modeled and then scaled down to 10.7- and 10-nm gate lengths, respectively. A TiN metal gate work-function granularity (MGG) and line edge roughness (LER) induced variability affecting OFF and ON characteristics are investigated and compared. In the OFF-region, the FinFETs have over an order of magnitude larger OFF-current that those of the equivalent GAA NWs. In the ON-region, the 25/10.7-nm gate length FinFETs deliver 20/58% larger ON-current than the 22/10-nm gate length GAA NWs. The FinFETs are more resilient to the MGG and LER variability in the subthreshold compared to the GAA NWs. However, the MGG ON-current variability is larger for the 10.7-nm FinFET than that for the 10-nm GAA NW. The LER ON-current variability depends largely on the RMS height; whereas a 0.6-nm RMS height yields a similar variability for both FinFETs and GAA NWs. Finally, the industry preferred 〈110〉 channel orientation is more resilient to the MGG and LER variability in both architectures.

/pdf/finfet-versus-gate-all-around-nanowire-fet-performance-2wdmnm8wlp.pdf

FinFET Versus Gate-All-Around Nanowire FET: Performance, Scaling, and Variability

Functional analysis : with applications

The Mesoarchaean -Palaeoproterozoic stratigraphic record of the Singhbhum crustal province, eastern India, implies sedimentation and volcanism in a changing tectonic scenario, and thus assumes immense geological significance Although efforts have been made by many researchers in the past several decades to summarize various geological aspects of the Singhbhum crustal province, a critical synthesis of various stratigraphic issues was long overdue The present contribution is an updated critical synthesis of the Mesoarchaean- Palaeoproterozoic stratigraphic record of the Singhbhum crustal province We have pointed out the problematic stratigraphic issues of the Singhbhum crustal province that deserve careful scrutiny in order to gain better insights into the mode of stratigraphic sequence building

Mesoarchaean-Palaeoproterozoic stratigraphic record of the Singhbhum crustal province, eastern India: a synthesis

FinFET is the backbone device technology for CMOS electronics at deeply scaled technology nodes per Moore’s law. Recently, the FinFET concept has been leveraged to develop a new generation of vertical power transistors based on wide-bandgap (WBG) and ultrawide-bandgap (UWBG) semiconductors for kilovolts and high-power applications. The sidewall gate-stack in a vertical power FinFET can rely on either a metal–oxide–semiconductor (MOS) structure or a p-n junction, rendering a Fin-MOSFET or a fin-based junction field-effect transistor (Fin-JFET), respectively. Although the device technologies are still at the early stage of development, 1.2-kV-class WBG gallium nitride (GaN) power Fin-MOSFETs have demonstrated one of the highest static and switching performances in all similarly rated power transistors; UWBG gallium oxide power Fin-MOSFETs have shown high performance up to a breakdown voltage over 2.6 kV. Early UWBG diamond lateral power Fin-MOSFETs have also been demonstrated. Meanwhile, GaN power Fin-JFETs are currently under active development. This article provides a comprehensive tutorial and review of the background and recent advances in WBG and UWBG vertical power FinFETs. It covers fundamental device physics, device and process development, as well as the static and switching performance of various power Fin-MOSFETs and Fin-JFETs. This article is concluded by identifying the current challenges and exciting research opportunities in this very dynamic research field.

(Ultra)Wide-Bandgap Vertical Power FinFETs

Since Moore’s law driven scaling of planar MOSFETs
faces formidable challenges in the nanometer regime, FinFETs and Trigate FETs have emerged as their successors. Owing
to the presence of multiple (two/three) gates, FinFETs/Trigate
FETs are able to tackle short-channel effects (SCEs) better than
conventional planar MOSFETs at deeply scaled technology nodes
and thus enable continued transistor scaling. In this paper, we
review research on FinFETs from the bottommost device level
to the topmost architecture level. We survey different types of
FinFETs, various possible FinFET asymmetries and their impact,
and novel logic-level and architecture-level tradeoffs offered by
FinFETs. We also review analysis and optimization tools that
are available for characterizing FinFET devices, circuits, and
architectures.

/pdf/finfets-from-devices-to-architectures-3wvjf3zgcz.pdf

FinFETs: From Devices to Architectures

Content addressable memories (CAMs) enable high-speed parallel search operations in table lookup-based applications, such as Internet routers and processor caches. Traditional CAM design has always suffered from the high dynamic power consumption associated with its large and active parallel hardware. However, deeply scaled technology nodes, with multigate devices replacing planar MOSFETs, are expected to bring new tradeoffs to CAM design. FinFET, a vertical-channel gate-wrap-around double-gate device, has emerged as the best alternative to planar MOSFET. In this brief, for the first time, we explore the design space of symmetric and asymmetric gate-workfunction FinFET CAMs. We propose several design alternatives and evaluate them in terms of their dc and transient metrics for different mismatch probabilities using technology computer-aided design simulations with 22-nm FinFET devices. We also propose two orthogonal layout styles for CAM design and show that one of them (vertical-search line) outperforms the other (vertical-match line) in terms of total power (22.3%) and search delay (5.8%).

Design of Efficient Content Addressable Memories in High-Performance FinFET Technology

FinFETs have begun replacing planar CMOS in the post-22 nm era because of their superior short-channel behavior. Though FinFETs will continue to extend Moore's law for the next few technology generations, 3-D vertical integration will enable more-than-Moore density increase by increasing the transistor count that can be accommodated in an IC package. Compared to conventional through-silicon-via (TSV)-based 3-D integration methods, monolithic 3-D integration enables higher density of transistors owing to the much smaller monolithic inter-tier vias (MIVs). In this paper, for the first time, we explore the design possibilities for FinFET-based ultra-high density monolithic 3-D SRAMs. These SRAMs can exploit the height difference between the n- and p-FinFETs placed in two different layers to improve overall SRAM stability. We investigate several 6T and 8T monolithic 3-D FinFET SRAM bitcells and evaluate their dc and transient stability/performance metrics, taking process variations into account. We propose a new 8T 3-D SRAM bitcell that shows a 39% improvement in read stability and 25% improvement in footprint area without affecting writeability, when compared with the conventional 2-D 6T SRAM bitcell.

Ultra-High Density Monolithic 3-D FinFET SRAM With Enhanced Read Stability

Several small lensoidal bodies of felsic volcanics are exposed in a curvilinear pattern within the brecciated granitoids of Bundelkhand Gneissic Complex (BGC) at Mohar. Sub-surface data reveals extensive presence of these felsic volcanics below the sediment of Vindhyan Supergroup. It occurs like a sheet with thickness varying from 12 m to 134 m. Its lateral extent has been traced upto 4.8 km. Multiple flows of felsic magma are identified based on colour, granularity, cross cutting relations and cyclic distribution of multiple vesicular bands along the entire thickness of felsic magma. The felsic rock contains upto 13.21% K2O. Chemical composition of these felsic volcanics varies across the column. Petrographically and chemically all these felsic volcanics are identified as rhyolite or rhyolite tuff.

Uranium mineralisation associated with felsic volcanism at Mohar, Shivpuri district, Madhya Pradesh

Rb-Sr isotopic data for the Tamparkola granite, northwest of Bonaigarh, and Bamra granite, southeast of Barnra, Sundergarh district, Orissa have yielded similar ages of 2746&#177144 Ma and 2738±28 Ma, respectively. Small granite exposures intruding the Iron Ore Group in the southern part of Tamparkola granite, have also indicated similar Whole Rock Rb-Sr age of 2867&#17786 Ma. These may be correlated with the Bonai granite. Significant crustal component was involved in the generation of these granites, as indicated by high initial Sr ratio, and their emplacement probably marks a major terminal cratonisation event in northwestern part of the Singhbhum-North Orissa Craton. Ths study does not support the view that the Tamparkola Granite is equivalent to the Itrna/Ekma granites that are intrusive into the Gangpur Group. These age results call for a revision of the stratigraphy of the Bonai-Gangpur tract, in that the Darjing Group unconformably overlies both the Bonai granite and Tamparkola granite, with the Mesoproterozoic Kunjar sedimentary sequence representing the youngest of the regional succession.

D. Bhattacharya

Papers

FinFETs: From Devices to Architectures

Design of Efficient Content Addressable Memories in High-Performance FinFET Technology

Ultra-High Density Monolithic 3-D FinFET SRAM With Enhanced Read Stability

Uranium mineralisation associated with felsic volcanism at Mohar, Shivpuri district, Madhya Pradesh

Geochronology of the Granitoids of the Kunjar Area, Sundergarh District, Orissa: Implications to the Regional Stratigraphy