Novel dual-threshold voltage FinFETs for circuit design and optimization

A great research effort has been invested on finding alternatives to CMOS that have better process variation and subthreshold leakage. From possible candidates, FinFET is the most compatible with respect to CMOS and it has shown promising leakage and speed performance. This thesis introduces basic characteristics of FinFETs and the effects of FinFET physical parameters on their performance are explained quantitatively. I show how dual- V th independent-gate FinFETs can be fabricated by optimizing their physical parameters. Optimum values for these physical parameters are derived using the physics-based University of Florida SPICE model for double-gate devices, and the optimized FinFETs are simulated and validated using Sentaurus TCAD simulations. Dual-14, FinFETs with independent gates enable series and parallel merge transformations in logic gates, realizing compact low power alternative gates with competitive performance and reduced input capacitance in comparison to conventional FinFET gates. Furthermore, they also enable the design of a new class of compact logic gates with higher expressive power and flexibility than CMOS gates. Synthesis results for 16 benchmark circuits from the ISCAS and OpenSPARC suites indicate that on average at 2GHz and 75°C, the library that contains the novel gates reduces total power and the number of fins by 36% and 37% respectively, over a conventional library that does not have novel gates in the 32nm technology

PERFORMANCE ANALYSIS OF FINFET BASED INVERTER, NAND AND NOR CIRCUITS AT 10 NM ,7 NM AND 5 NM NODE TECHNOLOGIES

Advancement in the semiconductor industry has transformed modern society. A miniaturization of a silicon transistor is continuing following Moore’s empirical law. The planar metal-oxide semiconductor field effect transistor (MOSFET) structure has reached its limit in terms of technological node reduction. To ensure the continuation of CMOS scaling and to overcome the Short Channel Effect (SCE) issues, a new MOS structure known as Fin field-effect transistor (FinFET) has been introduced and has led to significant performance enhancements.This paper presents a comparative study of CMOS gates designed with FinFET 10 nm, 7 nm and 5 nm technology nodes. Electrical parameters like the maximum switching current ION, the leakage current IOFF, and the performance ratio ION/IOFF for N and P FinFET with different nodes are presented in this simulation.The aim and the novelty  of this paper is to extract the operating frequency for CMOS circuits using Quantum and Stress effects implemented in the Spice parameters on the latest Microwind software. The simulation results show a fitting with experimental data  for FinFET N and P 10 nm strctures using quantum correction. Finally, we have demonstrate that FinFET 5 nm can reach a minimum time delay of  td=1.4 ps for CMOS NOT gate and td=1 ps  for CMOS NOR gate to improve Integrated Circuits IC

Conception et fabrication de FinFET GaN verticaux de puissance normalement bloqués

Abstract: The tremendous demands for high-performance systems driven by economic constraints forced the semiconductor industry to considerably scale the device's dimensions to compensate for the relatively modest Silicon physical properties. Those limitations pave the way for III-V semiconductors, which are excellent alternatives to Silicon and can be declined in many compositions. For example, Gallium Nitride (GaN) has been considered a fabulous competitor to facilitate the semiconductor industry's horizon beyond the performance limitations of Silicon due to its high mobility, wide bandgap, and high thermal conductivity properties for T>300K (Bulk GaN). It promises to trim the losses in power conversion circuits and drive a 10 % reduction in power consumption. Both lateral and vertical structures have been considered for GaN power devices. The AlGaN/GaN HEMT device's immense potential comes from the high density, high mobility electron gas formed at its heterojunction. The device is vulnerable to reliability issues resulting from the frequent exposure to high electric field collapse, temperature, and stress conditions, thus limiting its performance and reliability. Contrariwise, the vertical GaN power devices have attracted much attention because of the potential to reach high voltage and current levels without enlarging the chip's size. Furthermore, such vertical devices show superior thermal performance to their lateral counterparts. Meanwhile, Vertical GaN devices have the challenges of high leakage current and the breakdown occurring at the corners of the channel. Another challenge associated with Normally off devices is the lack of an optimized method for eliminating the magnesium diffusion from the p-GaN layer. This thesis has two strategic objectives; Firstly, a Normally-OFF GaN Power FinFET has been designed and optimized to overcome the vertical GaN FinFET challenges. It was done by optimizing the performance parameters such as threshold voltage VTH, high breakdown VBR, and the specific ON-state-resistance RON. Accordingly, the impact of both structural and physical parameters should be incorporated to have an exact optimization process. Afterward, the identification and optimization of a low-cost and high-quality fabrication process for the proposed structure underlined this thesis as the second objective.Les énormes demandes de systèmes à hautes performances motivées par des contraintes économiques ont forcé l'industrie des semi-conducteurs à réduire considérablement les dimensions des dispositifs pour compenser les propriétés physiques relativement modestes du silicium. Ces limitations ouvrent la voie aux semi-conducteurs III-V, qui sont d'excellentes alternatives au silicium et peuvent être déclinés dans de nombreuses compositions. Par exemple, le nitrure de gallium (GaN) a été considéré comme un concurrent fabuleux pour faciliter l'horizon de l'industrie des semi-conducteurs au-delà des limitations de performances du silicium en raison de sa grande mobilité, de sa large bande interdite et de ses propriétés de conductivité thermique élevées pour T>300K (Bulk GaN). Il promet de réduire les pertes dans les circuits de conversion de puissance et de réduire de 10 % la consommation d'énergie. À l'heure actuelle, les structures latérales et verticales ont été considérées pour les dispositifs de puissance en GaN. L'immense potentiel du dispositif HEMT AlGaN/GaN provient du gaz d'électrons à haute densité et à haute mobilité formé au niveau de son hétérojonction. Le dispositif est vulnérable aux problèmes de fiabilité résultant de l'exposition fréquente à des conditions d'effondrement de champ électrique, de température et de contrainte élevés, limitant ainsi ses performances et sa fiabilité. En revanche, les dispositifs de puissance verticaux en GaN ont attiré beaucoup d'attention en raison de leur capacité à atteindre des niveaux de tension et de courant élevés sans augmenter la taille de la puce. De plus, ces dispositifs verticaux présentent des performances thermiques supérieures à leurs homologues latéraux. Par ailleurs, les dispositifs GaN verticaux sont confrontés aux défis d'un courant de fuite élevée et de claquage se produisant aux coins du canal. Un autre défi associé aux dispositifs normalement bloqués est l'absence d'une méthode optimisée pour éliminer la diffusion de magnésium de la couche p-GaN. Cette thèse a deux objectifs stratégiques ; premièrement, un dispositif de puissance FinFET GaN normalement bloqué a été conçu et optimisé pour surmonter les défis du FinFET vertical en GaN. Cela a été fait en optimisant les paramètres de performance tels que la tension de seuil VTH, la tension de claquage VBR et la résistance spécifique à l'état passant RON. En conséquence, l'impact des paramètres structurels et physiques doit être incorporé pour avoir un processus d'optimisation précis. Par la suite, l'identification et l'optimisation d'un processus de fabrication à faible coût et de haute qualité pour la structure proposée à souligner cette thèse comme deuxième objectif

Oxygen-insertion Technology for CMOS Performance Enhancement

Until 2003, the semiconductor industry followed Dennard scaling rules to improve complementary metal-oxide-semiconductor (CMOS) transistor performance. However, performance gains with further reductions in transistor gate length are limited by physical effects that do not scale commensurately with device dimensions: short-channel effects (SCE) due to gate-leakage-limited gate-oxide thickness scaling, channel mobility degradation due to enhanced vertical electric fields, increased parasitic resistances due to reductions in source/drain (S/D) contact area, and increased variability in transistor performance due to random dopant fluctuation (RDF) effects and gate work function variations (WFV). These emerging scaling issues, together with increased process complexity and cost, pose severe challenges to maintaining the exponential scaling of transistor dimensions. This dissertation discusses the benefits of oxygen-insertion (OI) technology, a CMOS performance booster, for overcoming these challenges. The benefit of OI technology to mitigate the increase in sheet resistance ($R_{sh}$) with decreasing junction depth ($X_J$) for ultra-shallow-junctions (USJs) relevant for deep-sub-micron planar CMOS transistors is assessed through the fabrication of $R_{sh}$ test structures, electrical characterization, and technology computer-aided design (TCAD) simulations. Experimental and secondary ion mass spectroscopy (SIMS) analyses indicate that OI technology can facilitate low-resistivity USJ formation by reducing $R_{sh}$ and $X_J$ due to retarded transient-enhanced-diffusion (TED) effects and enhanced dopant retention during post-implantation thermal annealing. It is also shown that a low-temperature-oxide (LTO) capping can increase $R_{sh}$ unfavorably due to lower dopant activation levels, which can be alleviated by OI technology. This dissertation extends the evaluation of OI technology to advanced FinFET technology, targeting 7/8-nm low power technology node. A bulk-Si FinFET design comprising a super-steep retrograde (SSR) fin channel doping profile achievable with OI technology is studied by three-dimensional (3-D) TCAD simulations. As compared with the conventional bulk-Si (control) FinFET design with a heavily-doped fin channel doping profile, SSR FinFETs can achieve higher $I_{on}/I_{off}$ ratios and reduce the sensitivity of device performance to variations due to the lightly doped fin channel. As compared with the SOI FinFET design, SSR FinFETs can achieve similarly low $V_{DD,min}$ for 6T-SRAM cell yield estimation. Both SSR and SOI design can provide for as much as 100 mV reduction in $V_{DD,min}$ compared with the control FinFET design. Overall, the SSR FinFET design that can be achieved with OI technology is demonstrated to be a cheaper alternative to the SOI FinFET technology for extending CMOS scaling beyond the 10-nm node. Finally, this dissertation investigates the benefits of OI technology for reducing the Schottky barrier height ($\Phi_{Bp}$) of a Pt/Ti/p-type Si metal-semiconductor (M/S) contact, which can be expected to help reduce the specific contact resistivity for a p-type silicon contact. Electrical measurements of back-to-back Schottky diodes, SIMS, and X-ray photoelectron spectroscopy (XPS) show that the reduction in $\Phi_{Bp}$ is associated with enhanced Ti 2p and Si 2p core energy level shifts. OI technology is shown to favor low-$\Phi_{Bp}$ Pt monosilicide formation during forming gas anneal (FGA) by suppressing the grain boundary diffusion of Pt atoms into the crystalline Si substrate

Radiation Hardened by Design Methodologies for Soft-Error Mitigated Digital Architectures

abstract: Digital architectures for data encryption, processing, clock synthesis, data transfer, etc. are susceptible to radiation induced soft errors due to charge collection in complementary metal oxide semiconductor (CMOS) integrated circuits (ICs). Radiation hardening by design (RHBD) techniques such as double modular redundancy (DMR) and triple modular redundancy (TMR) are used for error detection and correction respectively in such architectures. Multiple node charge collection (MNCC) causes domain crossing errors (DCE) which can render the redundancy ineffectual. This dissertation describes techniques to ensure DCE mitigation with statistical confidence for various designs. Both sequential and combinatorial logic are separated using these custom and computer aided design (CAD) methodologies. Radiation vulnerability and design overhead are studied on VLSI sub-systems including an advanced encryption standard (AES) which is DCE mitigated using module level coarse separation on a 90-nm process with 99.999% DCE mitigation. A radiation hardened microprocessor (HERMES2) is implemented in both 90-nm and 55-nm technologies with an interleaved separation methodology with 99.99% DCE mitigation while achieving 4.9% increased cell density, 28.5 % reduced routing and 5.6% reduced power dissipation over the module fences implementation. A DMR register-file (RF) is implemented in 55 nm process and used in the HERMES2 microprocessor. The RF array custom design and the decoders APR designed are explored with a focus on design cycle time. Quality of results (QOR) is studied from power, performance, area and reliability (PPAR) perspective to ascertain the improvement over other design techniques. A radiation hardened all-digital multiplying pulsed digital delay line (DDL) is designed for double data rate (DDR2/3) applications for data eye centering during high speed off-chip data transfer. The effect of noise, radiation particle strikes and statistical variation on the designed DDL are studied in detail. The design achieves the best in class 22.4 ps peak-to-peak jitter, 100-850 MHz range at 14 pJ/cycle energy consumption. Vulnerability of the non-hardened design is characterized and portions of the redundant DDL are separated in custom and auto-place and route (APR). Thus, a range of designs for mission critical applications are implemented using methodologies proposed in this work and their potential PPAR benefits explored in detail.Dissertation/ThesisDoctoral Dissertation Electrical Engineering 201

Phase Noise Analyses and Measurements in the Hybrid Memristor-CMOS Phase-Locked Loop Design and Devices Beyond Bulk CMOS

Phase-locked loop (PLLs) has been widely used in analog or mixed-signal integrated circuits. Since there is an increasing market for low noise and high speed devices, PLLs are being employed in communications. In this dissertation, we investigated phase noise, tuning range, jitter, and power performances in different architectures of PLL designs. More energy efficient devices such as memristor, graphene, transition metal di-chalcogenide (TMDC) materials and their respective transistors are introduced in the design phase-locked loop. Subsequently, we modeled phase noise of a CMOS phase-locked loop from the superposition of noises from its building blocks which comprises of a voltage-controlled oscillator, loop filter, frequency divider, phase-frequency detector, and the auxiliary input reference clock. Similarly, a linear time-invariant model that has additive noise sources in frequency domain is used to analyze the phase noise. The modeled phase noise results are further compared with the corresponding phase-locked loop designs in different n-well CMOS processes. With the scaling of CMOS technology and the increase of the electrical field, the problem of short channel effects (SCE) has become dominant, which causes decay in subthreshold slope (SS) and positive and negative shifts in the threshold voltages of nMOS and pMOS transistors, respectively. Various devices are proposed to continue extending Moore\u27s law and the roadmap in semiconductor industry. We employed tunnel field effect transistor owing to its better performance in terms of SS, leakage current, power consumption etc. Applying an appropriate bias voltage to the gate-source region of TFET causes the valence band to align with the conduction band and injecting the charge carriers. Similarly, under reverse bias, the two bands are misaligned and there is no injection of carriers. We implemented graphene TFET and MoS2 in PLL design and the results show improvements in phase noise, jitter, tuning range, and frequency of operation. In addition, the power consumption is greatly reduced due to the low supply voltage of tunnel field effect transistor

Miniaturized Transistors, Volume II

In this book, we aim to address the ever-advancing progress in microelectronic device scaling. Complementary Metal-Oxide-Semiconductor (CMOS) devices continue to endure miniaturization, irrespective of the seeming physical limitations, helped by advancing fabrication techniques. We observe that miniaturization does not always refer to the latest technology node for digital transistors. Rather, by applying novel materials and device geometries, a significant reduction in the size of microelectronic devices for a broad set of applications can be achieved. The achievements made in the scaling of devices for applications beyond digital logic (e.g., high power, optoelectronics, and sensors) are taking the forefront in microelectronic miniaturization. Furthermore, all these achievements are assisted by improvements in the simulation and modeling of the involved materials and device structures. In particular, process and device technology computer-aided design (TCAD) has become indispensable in the design cycle of novel devices and technologies. It is our sincere hope that the results provided in this Special Issue prove useful to scientists and engineers who find themselves at the forefront of this rapidly evolving and broadening field. Now, more than ever, it is essential to look for solutions to find the next disrupting technologies which will allow for transistor miniaturization well beyond silicon’s physical limits and the current state-of-the-art. This requires a broad attack, including studies of novel and innovative designs as well as emerging materials which are becoming more application-specific than ever before

EFFICIENT HARDWARE PRIMITIVES FOR SECURING LIGHTWEIGHT SYSTEMS

In the era of IoT and ubiquitous computing, the collection and communication of sensitive data is increasingly being handled by lightweight Integrated Circuits. Efficient hardware implementations of crytographic primitives for resource constrained applications have become critical, especially block ciphers which perform fundamental operations such as encryption, decryption, and even hashing. We study the efficiency of block ciphers under different implementation styles. For low latency applications that use unrolled block cipher implementations, we design a glitch filter to reduce energy consumption. For lightweight applications, we design a novel architecture for the widely used AES cipher. The design eliminates inefficiencies in data movement and clock activity, thereby significantly improving energy efficiency over state-of-the-art architectures. Apart from efficiency, vulnerability to implementation attacks are a concern, which we mitigate by our randomization capable lightweight AES architecture. We fabricate our designs in a commercial 16nm FinFET technology and present measured testchip data on energy consumption and side channel resistance. Finally, we address the problem of supply chain security by using image processing techniques to extract fingerprints from surface texture of plastic IC packages for IC authentication and counterfeit prevention. Collectively these works present efficient and cost effective solutions to secure lightweight systems

Silicon Nanodevices

This book is a collection of scientific articles which brings research in Si nanodevices, device processing, and materials. The content is oriented to optoelectronics with a core in electronics and photonics. The issue of current technology developments in the nanodevices towards 3D integration and an emerging of the electronics and photonics as an ultimate goal in nanotechnology in the future is presented. The book contains a few review articles to update the knowledge in Si-based devices and followed by processing of advanced nano-scale transistors. Furthermore, material growth and manufacturing of several types of devices are presented. The subjects are carefully chosen to critically cover the scientific issues for scientists and doctoral students

Multi-Threshold Low Power-Delay Product Memory and Datapath Components Utilizing Advanced FinFET Technology Emphasizing the Reliability and Robustness

Indiana University-Purdue University Indianapolis (IUPUI)In this thesis, we investigated the 7 nm FinFET technology for its delay-power product performance. In our study, we explored the ASAP7 library from Arizona State University, developed in collaboration with ARM Holdings. The FinFET technology was chosen since it has a subthreshold slope of 60mV/decade that enables cells to function at 0.7V supply voltage at the nominal corner. An emphasis was focused on characterizing the Non-Ideal effects, delay variation, and power for the FinFET device. An exhaustive analysis of the INVx1 delay variation for different operating conditions was also included, to assess the robustness. The 7nm FinFET device was then employed into 6T SRAM cells and 16 function ALU. The SRAM cells were approached with advanced multi-corner stability evaluation. The system-level architecture of the ALU has demonstrated an ultra-low power system operating at 1 GHz clock frequency