vapordeposition

Vapor deposition is a group of vacuum-based processes used to produce thin films by transporting material from a source to a substrate in the vapor phase, where it condenses into a solid coating. The vapor can originate from solid or liquid precursors, and the methods differ in how the film material reaches the surface and how it forms.

Chemical vapor deposition (CVD) involves gas-phase chemical reactions that produce a solid film on or near the substrate. Precursors are introduced into a reactor where they react, decompose, or polymerize to form the desired material. CVD variants include low-pressure and atmospheric-pressure processes, which influence film conformity and step coverage. CVD is used to deposit materials such as silicon nitride, silicon dioxide, various carbides and nitrides, and carbon-based films.

Physical vapor deposition (PVD) relies on physical processes to transfer material from a source to the substrate. Methods include evaporation, sputtering, and pulsed laser deposition. In PVD, atoms or molecules are ejected from a target and travel to the substrate, forming dense, adherent films. PVD is common for metals, oxides, nitrides, and protective or functional coatings, including optical and hard coatings.

Atomic layer deposition (ALD) is a related technique that deposits films one atomic layer at a time through sequential, self-limiting surface reactions. This provides excellent thickness control and conformality, even on complex geometries, and is widely used in microelectronics and advanced coatings.

Applications of vapor deposition span semiconductor device fabrication, energy storage and conversion devices, optical coatings, protective wear and corrosion barriers, and catalytic or functional surfaces. Process parameters such as temperature, pressure, precursor chemistry, and deposition rate are critical to film quality and performance.