The nonstop scaling of Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFETs) is considered a driving force in semiconductor technology, allowing higher integration densities, enhanced performance, and reduced power consumption. However, fundamental challenges arise as device dimensions shrink to the nanoscale, such as short-channel effects, threshold voltage variation, leakage currents, and gate oxide tunneling. This study critically surveys these scaling limitations and shows potential solutions, such as high-k gate dielectrics, metal gate integration, and novel device architectures. Other transistor designs, including FinFETS, Gate-All-Around (GAA) transistors, and emerging beyond-CMOS devices, are assessed for their potential to extend Moore's Law. This study also addresses advancements in materials, including two-dimensional (2D) semiconductors and carbon-based nanostructures, that offer promising substitutes to conventional silicon technology. Regardless of these innovations, significant obstacles remain in achieving fabrication, reliability, and cost-effectiveness at sub-5nm nodes. This review paper provides insights into current progress and future guide for nanoscale MOSFET development, comprehensively assessing the challenges and opportunities in next-generation transistor technology. The findings aim to guide researchers and industry professionals toward sustainable semiconductor scaling approaches.
This review article discussed power amplifiers in modern wireless transmission systems, clarifying the determinants and restrictions of the create of power amplifiers in 5G and beyond transmission systems. The important topics of power amplifier design were discussed, which included solid-state techniques contributing to building the basic building block of the amplifier, furthermore to techniques for building the electronic circuit topology, while clarifying the importance of techniques for improving efficiency and linearity. This paper contributed to highlighting optimization and manufacturing techniques, focusing on the determinants and advantages of each technology. And clarifying the research space for researchers with the aim of developing a power amplifier that is optimal for use in modern wireless communications systems.