How Does Physical Vapor Deposition (PVD) Work?
Physical vapor deposition (PVD) - is a vacuum-based deposition technique in which a material is vaporized and then deposited onto the substrate surface.
In this deposition technique, the material (e.g. gold) that serves as the layer is heated so that it is brought to boiling point. The material thus becomes a gas and rises to the top where the substrate (e.g. silicon) is attached. Due to a lower temperature there, the gas condenses on the substrate surface. In this way, a thin layer is formed.
The deposition should happen in a high vacuum; at a pressure of about \(10^{-6}\) mbar. This reduces collisions with the air particles and thus improves the purity of the deposition, because otherwise the evaporated material can oxidize with air molecules, for example, and thus contaminate the substrate surface.
Instead of evaporating the material by means of a large electric current, this can also be done with an electron beam (Electron-beam physical vapor deposition) or laser beams (Pulsed laser deposition).