Microfabricageprocessen

Microfabricageprocessen, or microfabrication processes, describe the methods used to create micro-scale structures and devices, typically on semiconductor wafers such as silicon. The field developed with the rise of the integrated circuit and MEMS industries and encompasses a sequence of interdependent steps that define feature sizes from micrometers down to tens of nanometers.

A standard process flow includes substrate preparation, lithography to define patterns, etching to remove material, deposition to add films, and planarization to smooth surfaces. Lithography uses light or electrons passed through masks to transfer patterns onto a resist layer. Etching removes material selectively, through wet chemical or dry plasma methods, with dry etching (e.g., reactive ion or inductively coupled plasma) enabling high anisotropy. Deposition techniques such as chemical vapor deposition (CVD), physical vapor deposition (PVD), and atomic layer deposition (ALD) lay down materials with controlled thickness. Doping and diffusion modify electrical properties, while oxidation forms insulating layers.

Planarization and surface preparation, often by chemical-mechanical polishing (CMP), improve surface flatness for subsequent layers. Materials commonly processed include silicon, silicon dioxide, various metals, and polymers, with processes carried out in cleanroom environments to minimize contamination.

Applications span integrated circuits, MEMS (microelectromechanical systems), microfluidics, sensors, and optoelectronic devices. Process control relies on precision lithography, metrology, and defect management to achieve high yields. Environmental control, tool maintenance, and process integration across steps are crucial for reproducibility.

See also: microfabrication, nanofabrication, MEMS, semiconductor device fabrication.