Nidhi Nidhi

Bio: Nidhi Nidhi is an academic researcher from Intel. The author has contributed to research in topics: Transistor & Gate dielectric. The author has an hindex of 6, co-authored 19 publications receiving 404 citations.

A 22nm SoC platform technology featuring 3-D tri-gate and high-k/metal gate, optimized for ultra low power, high performance and high density SoC applications

Abstract: A leading edge 22nm 3-D tri-gate transistor technology has been optimized for low power SoC products for the first time. Low standby power and high voltage transistors exploiting the superior short channel control, < 65mV/dec subthreshold slope and <40mV DIBL, of the Tri-Gate architecture have been fabricated concurrently with high speed logic transistors in a single SoC chip to achieve industry leading drive currents at record low leakage levels. NMOS/PMOS Idsat=0.41/0.37mA/um at 30pA/um Ioff, 0.75V, were used to build a low standby power 380Mb SRAM capable of operating at 2.6GHz with 10pA/cell standby leakages. This technology offers mix-and-match flexibility of transistor types, high-density interconnect stacks, and RF/mixed-signal features for leadership in mobile, handheld, wireless and embedded SoC products.

A 14 nm SoC platform technology featuring 2 nd generation Tri-Gate transistors, 70 nm gate pitch, 52 nm metal pitch, and 0.0499 um 2 SRAM cells, optimized for low power, high performance and high density SoC products

Abstract: A leading edge 14 nm SoC platform technology based upon the 2nd generation Tri-Gate transistor technology [5] has been optimized for density, low power and wide dynamic range. 70 nm gate pitch, 52 nm metal pitch and 0.0499 um2 HDC SRAM cells are the most aggressive design rules reported for 14/16 nm node SoC process to achieve Moore's Law 2x density scaling over 22 nm node. High performance NMOS/PMOS drive currents of 1.3/1.2 mA/um, respectively, have been achieved at 0.7 V and 100 nA/um off-state leakage, 37%/50% improvement over 22 nm node. Ultra-low power NMOS/PMOS drives are 0.50/0.32 mA/um at 0.7 V and 15pA/um Ioff. This technology also deploys high voltage I/O transistors to support up to 3.3 V I/O. A full suite of analog, mixed-signal and RF features are also supported.

3D heterogeneous integration of high performance high-K metal gate GaN NMOS and Si PMOS transistors on 300mm high-resistivity Si substrate for energy-efficient and compact power delivery, RF (5G and beyond) and SoC applications

Abstract: We have demonstrated industry’s first 300mm 3D heterogeneous integration of high performance, low-leakage high-K dielectric metal gate enhancement-mode (e-mode) GaN NMOS and Si PMOS transistors on 300mm high-resistivity (HR) Si(111) substrate, enabled by 300mm GaN MOCVD epitaxy and 300mm 3D layer transfer. The fabricated (bottom device layer) high-K dielectric e-mode GaN NMOS transistors, integrated on a 300mm HR Si(111) substrate, show excellent electrical characteristics and figure-of-merits (FOM) for realizing energy-efficient, compact voltage regulators and RF front-end components such as power amplifiers, low-noise amplifiers and RF switches, with (i) I OFF as low as 100pA/μm (V D =5V, V G =0V), (ii) high I D,max =1.5mA/μm; (iii) R ON as low as 610Ω-μm, significantly better than industry-standard Si transistors at equivalent drain breakdown (BV D ), (iv) excellent RF performance: f T =190GHz, f MAX =300GHz, PAE=56% at mmwave frequency (f=28GHz), and PAE=70% at sub-7GHz (f=5GHz), significantly better than industry-standard GaAs and Si RF transistors, (v) excellent RF switch FOM, R on C off =110fs, and (vi) low noise figure, NF min =1.36dB (f=28GHz), 0.4dB (f=5GHz) and 0.27dB (f=1.8GHz), all at SoC-compatible voltages. The fabricated (top device layer) L G =65nm and 130nm Si PMOS transistors, which are monolithically integrated on top of the bottom GaN NMOS transistors by 300mm 3D layer transfer, show respectively, high drive current of 0.85mA/μm, and low I off of 150pA/μm at V D =-1.2V. Such a monolithic 3D integration of GaN NMOS and Si PMOS enables full integration of energy-efficient, truly compact power delivery and RF solutions with CMOS digital signal processing, logic computation and control, memory functions and analog circuitries for next generation power delivery, RF (5G and beyond) and SoC applications.

Transistor reliability characterization and comparisons for a 14 nm tri-gate technology optimized for System-on-Chip and foundry platforms

Abstract: The transistor reliability characterization of a 14nm System-on-Chip (SoC) node optimized for low power operation is described. In-depth assessments of reliability and performance for Core and I/O devices are performed on Logic and SoC nodes, and clear trends with scaling are identified. Insight is provided into hot carrier and off-state aging, and self-heat effects. Technological advancements across process nodes demonstrate the ability to achieve matched or improved reliability in conjunction with robust generational performance gains. The 14nm SoC node is shown to be robust for all transistor reliability modes. Process monitor data are used to demonstrate the stability of the production line in high-volume manufacturing.

Monolithic integration of high voltage transistors & low voltage non-planar transistors

Abstract: High voltage transistors spanning multiple non-planar semiconductor bodies, such as fins or nanowires, are monolithically integrated with non-planar transistors utilizing an individual non-planar semiconductor body. The non-planar FETs may be utilized for low voltage CMOS logic circuitry within an IC, while high voltage transistors may be utilized for high voltage circuitry within the IC. A gate stack may be disposed over a high voltage channel region separating a pair of fins with each of the fins serving as part of a source/drain for the high voltage device. The high voltage channel region may be a planar length of substrate recessed relative to the fins. A high voltage gate stack may use an isolation dielectric that surrounds the fins as a thick gate dielectric. A high voltage transistor may include a pair of doped wells formed into the substrate that are separated by the high voltage gate stack with one or more fin encompassed within each well.

Electronics based on two-dimensional materials

Abstract: The compelling demand for higher performance and lower power consumption in electronic systems is the main driving force of the electronics industry's quest for devices and/or architectures based on new materials. Here, we provide a review of electronic devices based on two-dimensional materials, outlining their potential as a technological option beyond scaled complementary metal-oxide-semiconductor switches. We focus on the performance limits and advantages of these materials and associated technologies, when exploited for both digital and analog applications, focusing on the main figures of merit needed to meet industry requirements. We also discuss the use of two-dimensional materials as an enabling factor for flexible electronics and provide our perspectives on future developments.

Two-dimensional semiconductors for transistors

Abstract: In the quest for higher performance, the dimensions of field-effect transistors (FETs) continue to decrease. However, the reduction in size of FETs comprising 3D semiconductors is limited by the rate at which heat, generated from static power, is dissipated. The increase in static power and the leakage of current between the source and drain electrodes that causes this increase, are referred to as short-channel effects. In FETs with channels made from 2D semiconductors, leakage current is almost eliminated because all electrons are confined in atomically thin channels and, hence, are uniformly influenced by the gate voltage. In this Review, we provide a mathematical framework to evaluate the performance of FETs and describe the challenges for improving the performances of short-channel FETs in relation to the properties of 2D materials, including graphene, transition metal dichalcogenides, phosphorene and silicene. We also describe tunnelling FETs that possess extremely low-power switching behaviour and explain how they can be realized using heterostructures of 2D semiconductors. Field-effect transistors (FETs) with semiconducting channels made from 2D materials are known to have fewer problems with short-channel effects than devices comprising 3D semiconductors. In this Review, a mathematical framework to evaluate the performance of FETs is outlined with a focus on the properties of 2D materials, such as graphene, transition metal dichalcogenides, phosphorene and silicene.

16.2 A 0.19pJ/b PVT-variation-tolerant hybrid physically unclonable function circuit for 100% stable secure key generation in 22nm CMOS

Abstract: Physically unclonable function (PUF) circuits are low-cost cryptographic primitives used for generation of unique, stable and secure keys or chip IDs for device authentication and data security in high-performance microprocessors [1][2][3][7]. The volatile nature of PUFs provides a high level of security and tamper resistance against invasive probing attacks compared to conventional fuse-based key storage technologies [4]. A process-voltage-temperature (PVT) variation-tolerant all-digital PUF array targeted for on-die generation of 100% stable, device-specific, high-entropy keys is fabricated in 22nm tri-gate high-κ metal-gate CMOS technology [5], featuring: i) a hybrid delay/cross-coupled PUF circuit where interaction of 16 minimum-sized, variation-impacted transistors determines resolution dynamics, ii) a temporal majority voting (TMV) circuit to stabilize occasionally unstable bits, resulting in 53% reduction in instability, iii) burn-in hardening to reinforce manufacturing-time PUF bias, resulting in 22% reduction in bit-errors, iv) soft dark bits for run-time identification and sequestration of highly unstable bits during field operation, resulting in 78% lower bit-errors, v) 19× separation between inter- and intra-PUF Hamming distance, enabling die-specific keys, vi) autocorrelation factor≈0 and entropy=0.9997, while passing NIST randomness tests, vii) high tolerance to voltage and temperature variation with 82% reduction in average Hamming-distance using a 100-cycle dark bit window, viii) in-situ PUF hardening by leveraging directed NBTI aging to improve stability during field operation, and ix) ultra-low energy consumption of 0.19pJ/b with compact bitcell layout of 4.66μm2 (Fig. 16.2.7a).

Ultra-thin chips for high-performance flexible electronics

Abstract: Flexible electronics has significantly advanced over the last few years, as devices and circuits from nanoscale structures to printed thin films have started to appear. Simultaneously, the demand for high-performance electronics has also increased because flexible and compact integrated circuits are needed to obtain fully flexible electronic systems. It is challenging to obtain flexible and compact integrated circuits as the silicon based CMOS electronics, which is currently the industry standard for high-performance, is planar and the brittle nature of silicon makes bendability difficult. For this reason, the ultra-thin chips from silicon is gaining interest. This review provides an in-depth analysis of various approaches for obtaining ultra-thin chips from rigid silicon wafer. The comprehensive study presented here includes analysis of ultra-thin chips properties such as the electrical, thermal, optical and mechanical properties, stress modelling, and packaging techniques. The underpinning advances in areas such as sensing, computing, data storage, and energy have been discussed along with several emerging applications (e.g., wearable systems, m-Health, smart cities and Internet of Things etc.) they will enable. This paper is targeted to the readers working in the field of integrated circuits on thin and bendable silicon; but it can be of broad interest to everyone working in the field of flexible electronics.

Carbon nanotube transistors scaled to a 40-nanometer footprint

Abstract: The International Technology Roadmap for Semiconductors challenges the device research community to reduce the transistor footprint containing all components to 40 nanometers within the next decade. We report on a p-channel transistor scaled to such an extremely small dimension. Built on one semiconducting carbon nanotube, it occupies less than half the space of leading silicon technologies, while delivering a significantly higher pitch-normalized current density—above 0.9 milliampere per micrometer at a low supply voltage of 0.5 volts with a subthreshold swing of 85 millivolts per decade. Furthermore, we show transistors with the same small footprint built on actual high-density arrays of such nanotubes that deliver higher current than that of the best-competing silicon devices under the same overdrive, without any normalization. We achieve this using low-resistance end-bonded contacts, a high-purity semiconducting carbon nanotube source, and self-assembly to pack nanotubes into full surface-coverage aligned arrays.