Chemical Vapor Deposition

There exists a multitude of chemical vapor deposition (CVD) processes. In thermally activated CVD (TACVD), the deposition is initiated and maintained by heat. This chapter introduces the underlying principles of thermally activated chemical vapor deposition (TACVD). In addition, large-area deposition and selective CVD on patterned substrates are discussed. CVD is a process where a solid material is deposited from a vapor by a chemical reaction occurring on or in the vicinity of a normally heated substrate surface. The resulting solid material is in the form of a thin film, powder, or single crystal. By varying experimental conditions, including substrate material, substrate temperature, and composition of the reaction gas mixture, total pressure gas flows, etc., materials with a wide range of physical, tribological, and chemical properties can be grown. A characteristic feature of the CVD technique is its excellent throwing power, enabling the production of coatings of uniform thickness and properties with a low porosity even on substrates of complicated shape. Another important feature is the capability of localized, or selective deposition, on patterned substrates. CVD and related processes are employed in many thin film applications, including dielectrics, conductors, passivation layers, oxidation barriers, conductive oxides, tribological and corrosion-resistant coatings, heat-resistant coatings, and epitaxial layers for microelectronics. Other CVD applications are the preparation of high-temperature materials (tungsten, ceramics, etc.) and the production of solar cells, high-temperature fiber composites and particles of well-defined sizes.