NEMsCAM: A novel CAM cell based on nano-electro-mechanical switch and CMOS for energy efficient TLBs

In this paper we propose a novel Content Addressable Memory (CAM) cell, NEMsCAM, based on both Nano-electro-mechanical (NEM) switches and CMOS technologies. The memory component of the proposed CAM cell is designed with two complementary non-volatile NEM switches and located on top of the CMOS-based comparison component. As a use case for the NEMsCAM cell, we design first-level data and instruction Translation Lookaside Buffers (TLBs) with 16nm CMOS technology at 2GHz. The simulations show that the NEMsCAM TLB reduces the energy consumption per search operation (by 27%), write operation (by 41.9%) and standby mode (by 53.9%), and the area (by 40.5%) compared to a CMOS-only TLB with minimal performance overhead.We thank all anonymous reviewers for their insightful comments. This work is supported in part by the European Union (FEDER funds) under contract TIN2012-34557, and the European Union’s Seventh Framework Programme (FP7/2007-2013) under the ParaDIME project (GA no. 318693)Postprint (author's final draft

An Energy-Efficient Design Paradigm for a Memory Cell Based on Novel Nanoelectromechanical Switches

In this chapter, we explain NEMsCAM cell, a new content-addressable memory (CAM) cell, which is designed based on both CMOS technologies and nanoelectromechanical (NEM) switches. The memory part of NEMsCAM is designed with two complementary nonvolatile NEM switches and located on top of the CMOS-based comparison component. As a use case, we evaluate first-level instruction and data translation lookaside buffers (TLBs) with 16 nm CMOS technology at 2 GHz. The simulation results demonstrate that the NEMsCAM TLB reduces the energy consumption per search operation (by 27%), standby mode (by 53.9%), write operation (by 41.9%), and the area (by 40.5%) compared to a CMOS-only TLB with minimal performance overhead

Single-contact, four-terminal microelectromechanical relay for efficient digital logic

Nano and microelectromechanical relays can be used in lieu of transistors to build digital integrated circuits that can operate with zero leakage current at high operating temperatures and radiation levels. Four-terminal (4-T) relays facilitate efficient logic circuits with greatly reduced device counts compared to three-terminal (3-T) relay implementations. Existing 4-T relays, however, require two moving contacts to simultaneously land on two stationary electrodes, which can adversely impact reliability, or have complex out-of-plane fabrication methods that can reduce yield and increase cost while having poor scalability. In this work an in-plane four-terminal relay with a single moving contact is demonstrated for the first time, through successful fabrication and characterization of prototypes with a critical dimension of 1.5 µm. Body biasing is shown to reduce the pull-in voltage of this 4-T relay compared to a 3-T relay with the same architecture and footprint. The potential of the 4-T relay to build efficient logic circuits is demonstrated by fabricating and characterizing a 1-to-2 demultiplexer (DEMUX) circuit using only two devices, a saving of eight devices over a 3-T relay implementation

Nanoelectromechanical relay without pull-in instability for high-temperature non-volatile memory

Emerging applications such as the Internet-of-Things and more-electric aircraft require electronics with integrated data storage that can operate in extreme temperatures with high energy efficiency. As transistor leakage current increases with temperature, nanoelectromechanical relays have emerged as a promising alternative. However, a reliable and scalable non-volatile relay that retains its state when powered off has not been demonstrated. Part of the challenge is electromechanical pull-in instability, causing the beam to snap in after traversing a section of the airgap. Here we demonstrate an electrostatically actuated nanoelectromechanical relay that eliminates electromechanical pull-in instability without restricting the dynamic range of motion. It has several advantages over conventional electrostatic relays, including low actuation voltages without extreme reduction in critical dimensions and near constant actuation airgap while the device moves, for improved electrostatic control. With this nanoelectromechanical relay we demonstrate the first high-temperature non-volatile relay operation, with over 40 non-volatile cycles at 200 ∘C

CMOS-NEMS Copper Switches Monolithically Integrated Using a 65 nm CMOS Technology

This work demonstrates the feasibility to obtain copper nanoelectromechanical (NEMS) relays using a commercial complementary metal oxide semiconductor (CMOS) technology (ST 65 nm) following an intra CMOS-MEMS approach. We report experimental demonstration of contact-mode nano-electromechanical switches obtaining low operating voltage (5.5 V), good ION/IOFF (103) ratio, abrupt subthreshold swing (4.3 mV/decade) and minimum dimensions (3.50 µm x 100 nm x 180 nm, and gap of 100 nm). With these dimensions, the operable Cell area of the switch will be 3.5 µm (length) x 0.2 µm (100 nm width + 100 nm gap) = 0.7 µm2 which is the smallest reported one using a top-down fabrication approach

Paired Storage Distributed Energy System Design for a Local Community Farm

This project considers the design of a renewable energy microgrid for a 19-acre community farm in San Luis Obispo, CA as the farm seeks to increase the magnitude of its electrical loads, and gain back-up electrical capability. The microgrid design will enable lower carbon emissions, reduce demand on the utility grid while saving on energy costs, and provide improved reliability and resiliency to the operator of the community farm. The eventual implementation of the design by a professional engineering entity will allow the community farm to expand its education program to include renewable energy as well as gain notoriety in the sustainability conscience community that City Farm relies on for donations. The design process will consist of 1) analysis of the farm’s existing electrical system and its loads, 2) a dive into State, local, and utility rules defining under what circumstances microgrids can be built interconnected to the grid, 3) analysis to estimate optimal component and resource sizing, and 4) recommending locations, components, protection and component settings for the smart distributed energy generation facility 5) analysis on safety, back up capacity, and financial feasibility of the design