3.4 Thin Film Deposition

Thin films play a vital role in virtually every micro- and nanostructure. The thin films consists of wide range of materials systems such as conductors, insulators and semiconductors. Conductors such as metals and metal compounds are used for connecting transistors, for contacts and for device structures. It can be found that interconnection is much harder than making transistors. Insulators are required for electrical isolation, as dielectrics for MOS structures and for mask applications etc. Semiconductors are essential to make transistors, diodes, resistors, capacitors and are used in amorphous and polycrystalline forms for variety of applications such as solar cells, epitaxial layers and electrical contacts etc.

Thin films made by a variety of means. Deposition technology can be classified in two groups i.e. depositions that happen because of a chemical reaction and that happen because of a physical reaction. Chemical Vapor Deposition, Electrodeposition, Epitaxy, and Thermal oxidation exploit the creation of solid materials directly from chemical reactions in gas and/or liquid compositions with the substrate material. In physical deposition technologies material is released from a source and transferred to the substrate. The most common examples are evaporation and sputtering.