A thin film is a layer of material ranging from fractions of a nanometer (monolayer) to several micrometers in thickness. Thin films are created through a process called “deposition.” Deposition is a thin film coating process, which is achieved by modifying the four states of matter, solid, liquid, vapor and plasma.
This can be accomplished through a variety of vacuum processes. Conventional categories of vacuum deposition processes include chemical vapor deposition (CVD), physical vapor deposition (PVD), evaporation through vacuum sublimation, or occasionally, some combination of these methods. These examples are just a few ways a thin film can be developed.
Thin films are ubiquitous. Some applications benefiting from thin film technology are electronic semiconductor devices. This includes integrated circuit chips, micro-fabricated mechanisms, micro-electromechanical systems (MEMS), micro-electronic optical systems, as well as light-emitting diodes (LEDs). Other mainstream applications include optical coatings, photovoltaic solar cells, and thin film batteries.
The performance of thin film optical coatings (e.g. antireflective, or AR, coatings) is typically enhanced when the thin film coating consists of multiple layers having varying thicknesses and refractive indices. Similarly, a periodic structure of alternating thin films of different materials may collectively form a superlattice, which exploits the phenomenon of quantum confinement by restricting electronic phenomena to two dimensions.
Ferromagnetic and ferroelectric thin films are used as computer memory.
Thin film technology is being explored as a means to substantially reduce the cost of photovoltaic systems, which are used to collect solar energy.
Thin film batteries can be deposited onto chips in any shape or size or can be flexible and printed onto plastic, thin metal, or paper using thin-film printing technology. A common use of thin film technology is in the manufacture of reflective, anti-reflective or self-cleaning glass.