Final answer:
MOSFETs are becoming smaller to enhance performance and increase transistor density, aligning with Moore's Law. Challenges of scaling include managing short-channel effects, leakage currents, heat dissipation, and variability due to quantum effects and material limits.
Step-by-step explanation:
The movement towards smaller dimensions in MOSFETs is primarily driven by the need to improve device performance and increase transistor density on a chip. This approach aligns with Moore's Law, which predicts a doubling of transistors on a microchip approximately every two years, leading to improved processing speeds, reduced power consumption, and lower costs.
Key challenges of scaling include maintaining control over short-channel effects, addressing increasing leakage currents, managing heat dissipation, and dealing with variability in transistor characteristics due to quantum effects and atomic-scale variations. Additionally, as devices shrink, the physical limits of materials and lithographic techniques become significant obstacles, requiring innovative solutions such as high-k dielectrics and advanced transistor architectures.