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Although spin transfer torque (STT)-based magnetic tunneling junction (MTJ) owns advantages of nonvolatility, nonlimited endurance, and fast write/read, its demand for high current density significantly casts a shadow over its future prospects. Recently, a novel three-terminal MTJ cell that combines voltage-controlled magnetic anisotropy (VCMA) effect and negative capacitance (NC) effect is proposed. Drawing support from the NC amplified VCMA effect and the three-step operation scenario, this novel MTJ cell can dramatically lower the energy consumption to fJ as well as keep high operation speed within nanoseconds. The feasibility of the proposed NC enhanced VCMA spintronics device for memory and logic application is proved by extensive physical simulation in our previous work. However, a SPICE compatible compact model of the proposed NC enhanced VCMA spintronics device is still demanded for circuit and system level evaluation. In this paper, we provide an accurate and fast compact model of NC enhanced VCMA device for both memory and logic applications. [ABSTRACT FROM AUTHOR]

In spite of the apparent simplicity of the system under study, compact modeling of complementary resistive switching (CRS) devices, i.e., two antiserially connected memristive structures, is by no means straightforward. This requires a deep understanding of the voltage drops occurring across the circuit elements and correct treatment of the so-called snapback (SB) effect typical of the breakdown process of a thin dielectric film in an MIS or a MIM structure. The SB effect fundamentally consists in a sudden reduction of the device resistance caused by the formation of a filamentary path spanning the insulator. Beyond this point, the filament widens keeping the voltage drop across its extremes constant. The consequence of disregarding this effect is clearly distinguishable in the simulated curves: progressive openings of the on-state windows for both positive and negative voltages instead of abrupt ones. In this paper, a modification is introduced in the original memdiode model for memristive devices in order to account for this remarkable feature. Ta2O5-based CRS devices are considered to demonstrate the suitability of our approach. [ABSTRACT FROM AUTHOR]

The accurate calculation of switching voltage (${V}_{s}$) is necessary for the reliable and low-power operation of monolithic 3-D (M3D) CMOS-nanoelectromechanical (NEM) hybrid reconfigurable logic circuits because ${V}_{s}$ corresponds to the operating voltage (${V}_{\text {dd}}$) of NEM memory switches. In this paper, based on the Euler–Bernoulli equation, the physics-based analytical model is proposed to determine ${V}_{s}$. The accuracy of the proposed model is verified by both the finite-element analysis and experimental results. Our proposed model shows >3% error compared with experimental data. Also, the design guidelines of NEM memory switches are presented in terms of minimum ${V}_{s}$ (${V}_{s\_{}{m}}$) and device dimensions. [ABSTRACT FROM AUTHOR]

This paper presents a methodology to model GaN power HEMT switching transients. Thus, a compact model to predict devices’ pulse switching characteristics and current collapse reliability issue has been developed. Parasitic RC subcircuits and a standard double-pulse switching tester to model intrinsic parasitic effects and to analyze power dissipation of GaN power HEMT are proposed and presented. Switching transient including gate-lag and drain-lag is predicted for ideal (without trap) and nonideal (with trap) devices. The results are validated by and compared to 2-D finite-element technology computer-aided design simulations. The original aim of this exercise is to develop a fast (near-real-time) model which can predict dynamic behavior of single and multiple power GaN HEMTs used for the switching transients of GaN power devices at circuit level. [ABSTRACT FROM PUBLISHER]

This paper analyzes write errors in spin-torque switching due to thermal fluctuations in a system with perpendicular magnetic anisotropy. Prior analytical and numerical methods are summarized; a physics-based general 2-D Fokker–Planck equation (FPE) is solved numerically. Due to its computational efficiency and broad applicability to all switching regimes and system symmetries, the 2-D FPE has been used to study the relation between write error slope and material parameters as well as some emerging switching schemes. [ABSTRACT FROM PUBLISHER]

A model of resistive random access memory (RRAM) cells aimed at providing an optimal programming/erase scheme in which the timing and biasing can be accurately optimized is proposed and implemented. To expedite technology development with an emphasis on ICs, a predictive model to capture the physical operation of every memory cell is needed. Although a number of compact RRAM models have been developed, this paper further considers the time-dependent reset process and the heat transfer in the conductive filaments. These phenomena are becoming critical in scaled memory cells and need to be carefully addressed. Due to the physical nature of the model, model parameters can be straightforwardly calibrated, relying on limited measurement data. The compact model is implemented using Verilog-A, and it is flexible for different circuit simulators. [ABSTRACT FROM PUBLISHER]

Emerging nonvolatile memories based on resistive switching mechanisms pull intense research and development efforts from both academia and industry. Oxide-based resistive random access memories (OxRAM) gather noteworthy performances, such as fast WRITE/READ speed, low power, high endurance, and large integration density that outperform conventional flash memories. To fully explore new design concepts, such as distributed memory in logic or biomimetic architectures, robust OxRAM compact models must be developed and implemented into electrical simulators to assess performances at a circuit level. In this paper, we propose a physics-based compact model used in electrical simulator for bipolar OxRAM memories. After uncovering the theoretical background and the set of relevant physical parameters, this model is confronted to experimental electrical data. The excellent agreement with these data suggests that this model can be confidently implemented into circuit simulators for design purpose. [ABSTRACT FROM PUBLISHER]

Magnetic tunnel junctions (MTJs) composed of ferromagnetic layers with perpendicular magnetic anisotropy (PMA) are of great interest for achieving high-density nonvolatile memory and logic chips owing to its scalability potential together with high thermal stability. Recent progress has demonstrated a capacity for high-speed performance and low power consumption through current-induced magnetization switching. In this paper, we present a compact model of the CoFeB/MgO PMA MTJ, a system exhibiting the best tunnel magnetoresistance ratio and switching performance. It integrates the physical models of static, dynamic, and stochastic behaviors; many experimental parameters are directly included to improve the agreement of simulation with experimental measurements. Mixed simulation based on the 65-nm technology node of a magnetic flip-flop validates its relevance and efficiency for MTJ/CMOS memory and logic chip design. [ABSTRACT FROM AUTHOR]