Microelectronic

Microelectronic engineering is a branch of electronics that studies the design and fabrication of very small electronic components and circuits. It centers on semiconductor devices, especially integrated circuits, which place many transistors, capacitors, and resistors on a single substrate to perform logic, memory, and analog functions.

The dominant technology is CMOS (complementary metal-oxide-semiconductor). Modern microfabrication uses a sequence of lithography, deposition, etching, diffusion, and ion implantation to build devices in front-end layers and interconnects in back-end layers.

Historically, the invention of the transistor in the mid-20th century and the subsequent development of integrated circuits enabled rapid device scaling and performance gains. Moore's law described the doubling of transistor density roughly every two years, though physical and economic limits are now challenging sustained scaling.

Materials include silicon as the primary substrate; gallium arsenide, silicon carbide, and other compounds are used for specialized high-frequency or power applications. The field encompasses digital, analog, and mixed-signal devices, as well as RF, and increasingly, microelectromechanical systems integrated with electronics.

Applications span consumer electronics, computing, telecommunications, automotive systems, and medical devices, with microelectronics underpinning most modern digital technologies.

Manufacturing and packaging involve cleanroom fabrication, front-end device fabrication, back-end interconnects, and final packaging. Common packaging approaches include flip-chip and ball-grid array. Design relies on electronic design automation (EDA) tools, while standards bodies such as JEDEC and IPC provide specifications. Key concerns include power dissipation, heat management, variability, and reliability.