Thin Films: Electro less plating uses a redox reaction to deposit metal on an object without the passage of an electric current. Because it allows a constant metal ion concentration to bathe all parts of the object, it deposits metal evenly along edges, inside holes, and over irregularly shaped objects which are difficult to plate evenly with electroplating. Electro less plating is also used to deposit a conductive surface on a nonconductive object to allow it to be electroplated. Electro less technology has been used for many decades but as technology raises this technique is rarely used.
A Langmuir-Blodgett (LB) film is a set of monolayer’s, or layers of organic material one molecule thick, deposited on a solid substrate. An LB film can consist of a single layer or many, up to a depth of several visible-light wavelengths. By transferring monolayer’s of organic material from a liquid to a solid substrate, the structure of the film can be controlled at the molecular level. Such films exhibit various electrochemical and photochemical properties. This has led some researchers to pursue LB films as a possible structure for integrated circuits (IC s). Ultimately, it might be possible to construct an LB-film memory chip in which each data bit is represented by a single molecule. Complex switching networks might be fabricated onto multilayer LB-films chips. Nanoshel uses this technique to deposit thin films.
Thermal oxidation: This is one of the most basic deposition technologies. It is simply oxidation of the substrate surface in an oxygen rich atmosphere. This is also the only deposition technology which actually consumes some of the substrate as it proceeds. The growth of the film is spurned by diffusion of oxygen into the substrate, which means the film growth is actually downwards into the substrate. This process is naturally limited to materials that can be oxidized, and it can only form films that are oxides of that material. This is the classical process used to form silicon dioxide on a silicon substrate.
Sputtering is a technology in which the material is released from the source at much lower temperature than evaporation. The substrate is placed in a vacuum chamber with the source material, named a target, and an inert gas (such as argon) is introduced at low pressure. Gas plasma is struck using an RF power source, causing the gas to become ionized. The ions are accelerated towards the surface of the target, causing atoms of the source material to break off from the target in vapor form and condense on all surfaces including the substrate. As for evaporation, the basic principle of sputtering is the same for all sputtering technologies.