Exploration of underlap induced high-k spacer with gate stack on strain channel cylindrical nanowire FET for enriched performance.

This research explores a comprehensive examination of gate underlap incorporated strained channel Cylindrical Gate All Around Nanowire FET having enriched performances above the requirement of the 2 nm technology node of IRDS 2025. The device installs a combination of strain engineering based quantum well barrier system in the channel region with high-k spacers sandwiching the device underlaps and stack high-k gate-oxide. The underlaps are prone to parasitic resistance and various short channel effects (SCEs) hence, are sandwiched by HfO2 based high-k. This SCE degradations and a strong electric field in the drain-channel region is rendered controlling the leakages. The strain based Nanosystem engineering is incorporated with Type-II heterostructure band alignment inducing quantum well barrier mechanism in the ultra-thin cylindrical channel region creating an electrostatic charge centroid leading to energy band bending and splitting among the two-fold and four-fold valleys of the strained Silicon layer. This provides stupendous electron mobility instigating high current density and electron velocity in the channel. Thereby, the device is susceptible to on-current enhancement via ballistic transport of carriers and carrier confinement via succumbing of quantum charge carriers. The device transconductance, Ion, Ioff, Ion/Ioff ratio are measured and the output performance (ID-VDS) characteristics is determined providing emphatic enrichments in contrast to the existing gate all-around FETs as well as the 2 nm technology node data of IRDS 2025. Hence, the strained channel Nanowire FET device developed here is presented here as the device of the future for various digital applications, RF applications and faster switching speed.

Evolution of type-II hetero-strain cylindrical-gate-all-around nanowire FET for exploration and analysis of enriched performances.

The incubation of strained nano-system in the form of tri-layered structure as nanowire channel in the cylindrical-gate-all-around (CGAA) FET at 10 nm gate length is developed for the first time to keep abreast with the proposed 3 nm technology node of IRDS 2022. The system installs Type-II hetero-strain alignment in the channel attesting itself as the fastest operating device debasing the SCEs at nano regime. The ultra-thin strained-channel comprises of two cylindrical s-Si wells encompassing s-SiGe barrier in between, which enables improvement of carrier mobility by succumbing of quantum charge carriers in the region. This results in 2D charge centroid creation with cylindrical based circular Nano-system contemplating electrostatic potential difference leading to enriched electric field, current density and transconductance, while the gate-all-around architecture with increased gate controllability lowers leakage current, in the device. The 10 nm strained-channel CGAA astounded havoc ON current enhancements of ~ 20% over 22 nm strained CGAA, 57% over Si CGAA FET and 75% over proposed 3 nm technology node IRDS 2022 are accomplished. Hence, carrier mobility and velocity enriches instituting quasi-ballistic transport through the Nanowire channel, thereby augments in ~ 28% drain current so the 10 nm channel CGAA FET stands as the most suitable and improved device in nano regime.

Development and Analysis of a Three-Fin Trigate Q-FinFET for a 3 nm Technology Node with a Strained-Silicon Channel System.

Multi-gate field effect transistors (FETs) such as FinFETs are severely affected by short-channel effects (SCEs) below 14 nm technology nodes, with even taller fins incurring fringing capacitances. This leads to performance degradation of the devices, which inhibits further scaling of nanoFETs, deterring the progress of semiconductor industries. Therefore, research has not kept pace with the technological requirements of the International Roadmap for Devices and Systems (IRDS). Thus, the development of newer devices with superior performances in terms of higher ON currents, acceptable leakage currents and improved SCEs is needed to enable the continuance of integrated circuit (IC) technologies. The literature has advocated integration of strained-silicon technology in existing FinFETs, which is highly effective in enhancing ON currents through the strain effect. However, the ON currents can also be amplified by intensifying the number of fins in trigate (TG) FinFETs. Thus, three-fin TG quantum (Q)-FinFETs, using a novel tri-layered strained-silicon channel, are deployed here at 10 nm and 8 nm channel lengths. Threshold voltage is calculated analytically to validate the designs. The electrical parameters and quantum effects of both devices are explored, analysed and compared with respect to existing heterostructure-on-insulator (HOI) FinFETs and the proposed existing standard requirement of IRDS 2022 for a 3 nm technology node. The comparisons demonstrated a significant increase in the drive currents upon employing three fins of the same dimensions (8 nm gate length) and specifications in a device-based system. The performance is augmented in contrast to the 3 nm technology node device of IRDS 2022, with SCEs within the limits. Thus, employing a tri-layered strained-silicon channel system in each fin allowed for forming a three-fin Q-FinFET that, in our opinion, is the technique for consolidating the performance of the devices and enabling future generation device for faster switching operation in a sub-nano regime.

A crossed-polarized four port MIMO antenna for UWB communication.

This paper presents a compact, crossed-polarized, ultra-wideband (UWB) four-ports multiple-input-multiple-output (MIMO) printed antenna. The proposed antenna is constructed from four microstrip circular patch elements fed by a 50-Ω microstrip line. Two metamaterial cell elements, in the form of a rectangular concentric double split ring resonator (SRR), are placed at the upper plane of the substrates for bandwidth improvement and isolation enhancement. The ultra-wideband frequency response is achieved using a defective ground plane. Surface current flow between the antenna's four elements is limited to ensure maximum isolation. The four-port MIMO system is designed with orthogonal antenna elements orientation on an FR4 substrate with a loss tangent of 0.02 and an overall size of 30 mm × 30 mm × 1.6 mm. Such orientation resulted in less than -17dB port-to-port isolation and an impedance bandwidth of 148% (3.1-12 GHz). The proposed UWB-MIMO antenna achieved a maximum realized gain of 6.2dBi with an efficiency of 87%. The measured and simulated results are in good agreement over the operating frequency band (3.1-12 GHz). The results also provide overall good diversity performance with the TARC < -10 dB, ECC < 0.001, DG > 9.9, MEG < -3 dB and CCL <0.1. The proposed antenna is well-suited for applications in WLAN, WIMAX and GPRs.

Quad-port multiservice integrated optically transparent automotive antenna for vehicular classification applications.

The demand for vehicular antennas increases in tandem with the need for multiple features in automobiles. The development of optically transparent antenna (OTA) has made it possible to deploy antennas on delicate surfaces such as glass. Earlier studies on OTA demonstrated its viability using materials such as transparent conducting oxides (TCO) and conductive polymers. A tri-band OTA is proposed in this paper for vehicular applications. The antenna operates at 1.8 GHz, 2.4 GHz and 3.39-12 GHz bands, covering automotive/wireless applications such as GSM, Bluetooth, Wi-Fi, vehicular communication and electronic toll collection. The proposed OTA is developed on soda lime glass, and the material TCO is used for the radiator and the ground plane. The antenna prototype is tested on windshield and in an anechoic chamber, the gain and efficiency are found to be greater than 1 dBi and 80%, respectively. Furthermore, a machine learning technique for vehicle classification is proposed, which could help in electronic toll collection, automatic vehicle identifier, and parking management applications. The presented algorithm achieves 80% classification accuracy with a minimum window size.

Functionalized-CNT Polymer Composite for Microwave and Electromagnetic Shielding.

In this research work, we studied the microwave properties of multi-wall carbon nanotube (MWCNT) surface functionalized with metallic oxides composites. Three different concentrations (5%, 10%, and 20%) of metallic oxides were used, namely cobalt, iron, and cobalt ferrite. The surface-decorated CNTS were impregnated into polyurethane (PU) matrix. The surface-decorated MWCNTs and the MWCNTs-PU composites were characterized using electron microscopy. The dielectric properties of the samples are studied using an open-ended coaxial probe technique in a wide frequency range of (5-50 GHz). The metallic oxide-decorated surface MWCNTs-PU composites demonstrated different microwave-frequency absorption characteristics depending on the concentration of the metallic oxides.

A compact multiband planar antenna using modified L-shape resonator slots.

A multiband planar antenna designed and proposed with resonator slots is presented. The proposed antenna consists of a planar hexagonal patch composed of two pairs of resonator slots. The antenna is designed using Isola FR408 substrate (εr = 3.68 and tanδ = 0.0092) with a compact dimension of 21 × 28 × 1.6 mm3. The designed antenna has good impedance matching and radiation characteristics for the desired multiband frequencies. Multibands are obtained by etching two pairs of modified mirror-imaged L-shaped resonator slots on the hexagonal planar patch. Simulated and measured results of the antennas' reflection coefficient are provided and there is good agreement between the simulation and measurement results. The antennas' measured peak gains are between 2 dB and 5 dB and measured efficiencies are between 40% and 80%. The proposed antenna, when compared to other antennas, exhibits multiband characteristic by using a single-feed structure and generates different combinations of isolated lower frequency bands in miniature size. The antenna has stable directional radiation patterns and has the potential to meet the requirements of wireless communications applications.

Microwave Absorbing properties of metal functionalized-CNT-polymer composite for stealth applications.

In this study, we report on the electrical properties of multi-wall carbon nanotubes (MWCNT) composites functionalized with metal or metal alloy oxides and embedded in a polyurethane matrix to develop a lightweight material for microwave absorption and shielding. The CNT nanoparticles are functionalized with metallic oxides such as Cobalt oxide, Iron oxide, and Cobalt Iron oxide, at three different concentrations. Metallic oxides are used at 5%, 10%, and 20% concentration of the total CNT percentage weight. The resulting functionalized CNT is mixed with polyurethane polymer at 5% wt of the total composite weight. Three sets of cylindrical samples are developed, and each set contains three different metal oxide concentrations. The dielectric properties of the nine developed samples are obtained by measuring their permittivity spectra using an open-ended coaxial probe technique in the spectral range 5-50 GHz. The absorption efficiency of the composites is then obtained by calculating the reflection loss at normal incidence. The results show that the spectral range of absorption can be tuned by changing the CNT concentration, and the material thickness. Functionalized CNT with different alloyed metal oxides enhanced the absorption efficiency of the polyurethane/CNT composites. Such functionalized composites can be used to replace the common heavyweight materials used for microwave applications.