nanofabrication

Nanofabrication is the design and manufacture of devices and structures with features on the nanoscale, typically 1 to 100 nanometers. It encompasses both top-down and bottom-up approaches and is a central activity in nanotechnology.

Top-down methods remove material to create tiny patterns and structures. Key techniques include photolithography, electron-beam lithography, nanoimprint lithography, and focused ion beam milling. Bottom-up methods build structures atom by atom or molecule by molecule through self-assembly, chemical synthesis, or vapor-phase deposition.

Materials used span silicon and other semiconductors, metals, oxides, polymers, carbon-based materials such as graphene and carbon nanotubes. Nanofabrication often takes place in cleanrooms with stringent environmental controls and relies on precise metrology from electron microscopy, atomic force microscopy, and other characterization tools.

Applications include micro- and nanoelectronics, photonics and plasmonics, sensors, energy storage and conversion devices, and biomedical components. Nanofabrication also underpins microelectromechanical systems (MEMS) and nanoelectromechanical systems (NEMS).

Challenges include achieving high resolution with high throughput, controlling defects and variability, achieving reliable integration with larger-scale processes, and reducing cost. Ongoing research seeks new materials, self-assembly strategies, and improved metrology and standards.