Chemical Vapor Deposition

Chemical Vapor Deposition (CVD) is a method of epitaxially depositing films of solid materials on the surface of a substrate during the vapor phase of a controlled chemical reaction. CVD, also called thin-film deposition, is used prevalently for electronics, optoelectronics, catalysis, and energy applications, such as semiconductors, silicon wafer preparation, and printable solar cells.

The CVD technique is a versatile and quick method to support film growth, enabling the generation of pure coatings with uniform thickness and controlled porosity, even on complicated or contoured surfaces. In addition, large-area and selective CVD is possible on patterned substrates. CVD provides a scalable, controllable, and cost-effective growth method for the bottom-up synthesis of two-dimensional (2D) materials or thin films such as metals (e.g., silicon, tungsten), carbon (e.g., graphene, diamond), arsenides, carbides, nitrides, oxides, and transition metal dichalcogenides (TMDCs). To synthesize well-ordered thin films, high-purity metal precursors (organometallics, halides, alkyls, alkoxides, and ketonates) are required.

The composition and morphology of layers varies depending on the chosen precursors and substrate, temperature, chamber pressure, carrier gas flow rate, quantity and ratio of source materials, and source-substrate distance for the CVD process. Atomic layer deposition (ALD), a subclass of CVD, can provide further control of thin film deposition through sequential, self-limiting reactions of precursors on a substrate.