Microfabrication is the process of fabricating miniature structures of micrometre-scale or smaller. It is also sometimes referred to as microtechnology, nanotechnology, or micromanufacturing. Microfabrication is used in the manufacture of semiconductor devices (e.g. transistors, integrated circuits), optoelectronic devices (e.g. light-emitting diodes), sensors, and other microelectromechanical systems (MEMS).
Microfabrication has its origins in lithography, a process used to pattern surfaces since the 19th century. In the 1950s photolithography was adapted for use in semiconductor device fabrication, and by the early 1960s it had become the primary means for creating patterns on silicon wafers in the production of MOSFETs and other transistor types. As feature sizes have decreased over time—a trend known as Moore’s law—the application of photolithography has continued to be central to microfabrication processes; today it remains an essential step in almost all semiconductor device fabrication.(1)
Early microprocessors were fabricated using a variety of manual methods including wire bonding and die attachment.(2) These methods are still used for low volume production or prototyping but they are not well suited for high volume manufacturing due to their inherent lack of scalability.(3) For high volume production modern microprocessors are manufactured using automated processes such as chemical-mechanical planarization (CMP) and etching that are capable of patterning features with dimensions measured in tens of nanometres.(4)
The term “microfabrication” can refer to a wide range of different technologies that share common goals: producing small structures with precise control over their shape, size, composition, and surface properties.(5) The most common methodologies employed in microfabrication include: deposition (of thin films),(6) removal (of material using etching techniques),(7) additive manufacturing/3D printing,(8)(9)(10)(11)(12)(13)(14)(15) moulding/casting/(16)(17)(18); imprint lithography;(19)-(21)-(22)-(23)- atomic layer deposition-(24); epitaxy-(25); ion implantation; laser ablation; electrodeposition; drawing.(26)-(27 ) Each technique has its own advantages and disadvantages that must be considered when choosing a fabrication approach for a given application.(28 )