Nanoelectronic Devices and Applications

Quantum well devices based on III-V heterostructures outperform Field Effect Transistors (FETs) by harnessing the exceptional properties of the twodimensional electron gas (2DEG) in various material interface systems. In high-power electronics, III-V-based Gallium Nitride (GaN) HEMTs can have a great influence on the transport industry, consumer, RADAR, sensing systems, RF/ power electronics, and military systems. On the other hand, the devices made of HEMTs and MIS-HEMTs work in enhancement mode, having very low leakage current, which can conserve energy for more efficient power conversion, microwave/ power transistors and highspeed performance for wireless communication. The existing physics of the wellestablished AlGaN heterostructure system imposes constraints on the further progress of GaN-based HEMTs. Some of the scopes include: Initially, the semiconductor materials made of SiC, GaN, and AlGaN allow a device that is resistant to severe conditions, such as high-power /voltage-high temperature, to operate due to its effective dielectric constant and has a very good thermal conductivity, which makes this device well-suited for military applications. Secondly, with the urgent need for high-speed internet multimedia communication across the world, high transmission network capacity is required. GaN-based HEMT devices are suitable candidates for achieving high-speed limits, high gain and low noise performance. In conclusion, GaN and related interface materials exhibit chemical stability and act as robust semiconductors, exhibiting remarkable piezoelectric polarization effects that lead to a high-quality 2DEG. Integrating free-standing resonators with functionalized GaNbased 2DEG formation reveals the potential for designing advanced sensors.

Sensors that detect variations in the surroundings and convert them into electrical signals are crucial in numerous fields, including healthcare, manufacturing, and environmental monitoring. Optical sensors, in terms of various sensing principles, hold considerable potential due to their fast response, high sensing resolution, and ability to withstand magnetic interference. Despite their advantages, traditional optical sensing techniques also have certain limitations, such as bulky structures, tedious alignment procedures, and high production expenses. To address this issue, on-chip integration has been proposed, and GaN and its alloys can be ideal materials due to their high efficiency, long lifespan, and high stability. By simultaneously forming the light emitter and photodetector on a shared substrate through wafer-fabrication processes, miniaturized GaN optical sensors possess a compact design, small size, high robustness, low manufacturing cost, and simple operations. This chapter discusses the working mechanisms and influencing factors of integrated GaN devices alongside their recent progress in advanced sensing applications.

III-nitride nanowire light-emitting diodes (LEDs) have emerged as the nextgeneration solid-state lighting technology. Currently, white-light LEDs rely on the phosphor-converted white LED (pc-WLEDs) technology, which normally depends on the mixture of blue/ultraviolet emitters and green/yellow/red color-converters. In this chapter, a summary of current research progress on nanophosphors and their applications in improving the device performance of InGaN nanowire pc-WLEDs in terms of color rendering properties and optical and electrical characteristics is presented. These investigations have concentrated on manufacturing methods, morphologies, optoelectronic characterizations and device performances. By concentrating on these critical elements, our goal is to contribute valuable insights and advancements to the field, paving the way for the continued development and application of III-nitride nanowire LEDs in the landscape of solid-state lighting technologies. 

The electron transport lifetime τ in low-dimensional semiconductor devices based on quantum well structures is an important parameter that decides the transport as well as optical properties. In recent times, the utilization of non-square quantum well structures has boosted the optoelectronic device performance. This chapter reports the variation of τ with the applied electric field Fapp in Alx Ga1-x As-based modulation doped double quantum well (DQW) structures by considering non-square potential profiles such as parabolic (P), V-shaped (V), semi-parabolic (SP), and semi-V-shaped (SV). Here, τ is analyzed by adopting ionized impurity (imp) and alloy disorder (al) scatterings. In the case of DPQW and DVQW systems, two subbands are occupied from Fapp = 0 up to |Fapp| = 5.6 kV/cm. After that, only one subband is occupied. On the other hand, in the case of DSPQW and DSVQW, there occurs the occupation of only a single lowest subband energy level for all Fapp. It is significant to note that the effect of the scattering mechanism on the subband transport lifetime differs by changing the structure potential. For example, when both lower and upper subbands are filled, in the case of DPQW, the imp-scattering decides τ, whereas, in the case of DVQW, both impand al-scatterings equally contribute. The results of τ in the structures given below are compared with the conventional double square quantum well (DSQW) structure and show that τ (DPQW) > τ (DVQW) > τ (DSQW) at Fapp = 0. The results of τ in nonsquare DQW structures will be very helpful in understanding the intricacies of the electro-optical properties of emerging low-dimensional semiconductor devices.

High electron mobility transistors (HEMTs) and III-V compound materials are the key research and development fields for developing improved high-power solid-state devices and integrated circuits (ICs). GaN-based HEMTs have recently gained popularity owing to their usage in high-power and high-frequency applications. This chapter explains different types of heterostructures, principle operations, and basic structures in detail, along with different types of HEMT structures. In order to understand the operation and behavior of the High Electron Mobility Transistor (HEMT) device, internal operation with in-depth analysis is very essential. Therefore, the physics behind the operation of HEMT with proper analysis with the help of neat illustrations is also discussed. Finally, the chapter concludes with a thorough analysis of the breakthrough HEMT architecture and the difficulties posed by HEMTs. 

In this chapter, studies of the DC characteristics of AlGaN/GaN HEMT (High Electron Mobility Transistor) and its compact model are presented. It includes the working principles of different HEMT models, their advantages, and their use in high-frequency and high-power applications. The chapter provides a distinct idea about the properties of different models (EE, ASM, and MVGS) and their DC characteristics, which are generated by the Advanced Design System (ADS). The performance analysis of the proposed HEMT models in terms of high electron mobility, high-power and high-frequency operation, low noise amplification, and high thermal stability, along with challenges and future scopes, is discussed in this chapter.

GaN-based High Electron Mobility Transistors are currently exhibiting exceptional performance in areas that handle high power, high frequency, etc. In particular, their outstanding electrical control characteristics that were demonstrated in HEMT (High Electron Mobility Transistors) based on GaN material made them very promising due to their fundamental and intrinsic unparalleled properties over the existing technologies that use Si-based materials. When a technology enters the manufacturing stage, reliability remains an important challenge. So, it is essential to strongly encourage the knowledge database on the reliability of GaN-based HEMTs. This study focuses on the primary issues that have impacted the reliability of GaNbased HEMTs in both the past and the present. The article focuses on the main problems that have affected the dependability of GaN-based HEMTs both in the past and present, followed by difficulties and potential future applications.

Gallium Oxide (Ga2O3 ) is an emerging semiconductor material that has gained significant attention in the field of electronics due to its unique properties and potential applications. Gallium Oxide has a very large bandgap of around 4.8-4.9 eV; this wide bandgap allows gallium oxide to withstand higher breakdown voltages and is well-suited for high-power switches, high-voltage rectifiers and inverters. Gallium oxide-based power electronics can operate at higher voltages and temperatures, enabling efficient energy conversion and reducing losses. In this book, we have discussed the physical properties, growth, and deposition methods along with the various applications of Gallium Oxide. We have even simulated a Gallium Oxide FINFET and discussed its electrical parameter’s behavior and various RFIC parameters for different fin widths. 

In the present research, a β-Ga2O3 high electron mobility transistor is proposed for investigating the implementation of high-k dielectric materials. The implementation of the dielectrics, Si3N4 , Al2O3 , and HfO2, at the interface of aluminum nitride (AlN) and the gate is depicted to determine the optimal selection. The novelty of the device lies in the highly doped n+ material with a broader gap between ohmic contact and the barrier layers. The performance is computed regarding the transfer and output characteristics, transconductance, gate capacitance, 2nd and 3rd-order transconductance, sub-threshold voltage, on-resistance and output conductance. The crucial parameters for switching and linearity performance are also assessed. The results demonstrate significant improvements in dynamic and access resistance, leading to a remarkably high transconductance (Gm ) value of 0.15 S/µm and a peak drain current density of 650 A/mm at Vds = 5 V. These promising results pave the way for potential applications in high-power radio frequency and microwave devices, making the proposed device a promising candidate for future advancements in these fields.

In this chapter, we studied the device-level performance based on electrostatic parameters of a source pocket engineered raised buried oxide (RBOX) SOI tunnel field-effect transistor (SP-RBOX-SOITFET). Using Si1-xGex pockets between the channel and the source, steep subthreshold swing transistors can be obtained. In the pocket, a narrow n+ region is formed by a tunneling junction between the p+ region of the source. In order to reduce subthreshold swing, the tunneling width must be narrowed, and the lateral electric field must be increased. So, the studied structure can be used to design the dielectric modulated biomolecule biosensors for IOTs applications. Simulation analyses of the proposed work has been conducted using the Silvaco ATLAS TCAD tool.

In this study, a SiGe source-based epitaxial layer-encapsulated TFET (SiGe source ETLTFET) is developed, and the performance of the device is examined by optimizing various design parameters, including the epitaxial layer thickness (tepi), gateto-source overlap length (Lov), Ge mole fraction, and source doping concentration. The average subthreshold swing (SSavg) and ON-OFF current ratio are used to evaluate the device’s performance. The results show a superior performance of SiGe source ETLTFET compared with its homojunction counterpart. Furthermore, to demonstrate the possibilities for using the proposed device in a logic circuit, a resistive load inverter is designed using the n-type ETLTFET.

In this study, a heterodielectric BOX (HDB) Nanoribbon FET (NR-FET) is built using the TCAD device simulator to reduce the effect of trap charges on numerous electrical properties in traditional NR-FETs. Initially, a reasonable study in terms of transfer characteristics of NR-FET is highlighted between homodielectric and HD BOX. Because of the existence of high-k dielectric below the drain area, it is assumed that the impact of trap charges is insignificant in HDB NR-FET. Furthermore, the trap charge effect on transconductance (gm ), total gate capacitance (Cgg), and cut-off frequency (fc ) in HDB NR-FETs are investigated. Higher-order harmonics of gm (gm2 and gm3) and linearity parameters are studied for HDB NR-FET in a series of steps. Finally, the effect of temperature on input characteristics, gm , Cgg, fc , gm2, gm3, and linearity behavior for HDB NR-FET is investigated in the presence of trap charges.

Due to the shortening of channel length in accordance with Moore’s law, short channel effects degrade transistor performance. This chapter explains the emerging nanosheet fin field effect transistor (FinFET) design and operation through technology computer-aided design (TCAD) tool-based design and simulation. A 10 nm node Ge-channel nanosheet FinFET is designed and simulated by incorporating quantum transport models in both DC and AC environments. Corresponding short channel effect (SCE) parameters are obtained and compared with Si-channel nanosheet FinFETs. Further, device feasibility for low-power and high-frequency applications is studied.

Nowadays, a wide range of viruses, bacteria, cancers, and other diseases have emerged due to drastic changes in the environment and climate, as well as changes in human habitation and lifestyle. Some viruses, like the coronavirus (COVID19), are potentially fatal, causing a global pandemic and leading to millions of deaths worldwide. Therefore, the development of biosensors is necessary to identify these viruses and cancers at an early stage. The book chapter aims to discuss the development of biosensors based on different device technologies (FET, AlGaAs/GaAs, AlGaN/GaN) with their performance characteristics toward biosensing applications. This chapter also focuses on two important detection techniques, labelbased and label-free biosensing, and compares them with several performance factors. The performance characteristics of FET-based biosensors, AlGaAs-based biosensors, and AlGaN-based biosensors are covered in this book chapter.

In this chapter, we study the characteristics of the 2-dimensional material Tungsten Diselenide (WSe2 ), along with its properties, applications, and challenges. Here, we present in detail the evaluation of TMDC materials and other 2D materials available in comparison to WSe2 materials. We also differentiate these materials based on their qualities, characteristics, advantages, and applications in detail. Later, we discuss the designed device structure of the WSe2FET along with its simulation results. Simulation analysis describes the input and output characteristics of a transistor with WSe2 as channel material and compares its response with the conventional MOSFET. Thereafter, we discuss the hetero-dielectric structure performance with different high-K values, and then a dielectric-modulated biosensor device is designed to study its characteristics and sensitivity. It is observed from the analysis that hetero-dielectric structure devices have a high Ion/Ioff current ratio compared to conventional MOSFET due to high interface layers interaction and high gate controlling capability. Finally, we study the sensitivity behavior of the device and understand that as the K-value rises, the device sensitivity increases because of the high electrostatic property in nature. WSe2 has a larger surface-to-volume ratio, which provides a larger sensing area for interactions with biomolecules, potentially enhancing the sensitivity of the biosensor.

Silicon-based semiconductor devices have sustained Moore’s Law for a long time. However, with the downscaling of devices, the focus of the industry has shifted toward alternative materials having application-specific properties. Memristors have emerged as one of the prospective semiconductor devices for multi-faceted applications due to their data retention properties, convenient fabrication, and less complex circuit architectures. The dual resistance states of memristors have been employed in multiple intelligent applications, including brain-inspired computing architectures, methods, cryptography frameworks, and biological sensing. The non-volatility of memory and compatibility with CMOS-style architecture have led to a wide range of domains that are capable of exploiting the properties of memristors. A number of mathematical models have also been developed to explain the working principle of memristors. This chapter reviews the theory and applications of memristors for the silicon era and presents the future perspectives of these devices for the post-silicon era.