Deposition

[Deposition] A semiconductor fabrication process wherein a thin film is applied to awafer surface to impart electrical characteristics. The deposition process is the step where a thin film of a given substance is applied onto the surface of a wafer, giving the wafer electrical characteristics. The process involves applying multiple layers of a material at the molecular or atomic level onto a wafer. The level of thinness and uniformity of the film determine the semiconductor quality and, therefore, is a crucial step in semiconductor fabrication. Because the coating is so thin, the technology needs to be intricate and precise. The two types of deposition are physical vapor deposition (PVD) and chemical vapor deposition (CVD). PVD (physical vapor deposition) is used primarily to deposit metal films and is not accompanied by chemical reaction. Meanwhile, CVD (chemical vapor deposition) involves applying external energy to vapor of particles formed by a chemical reaction of gas. It can be used to deposit thin films on conductors, insulators and semiconductors alike.