Physical vapor deposition process availability

Seshan, K. 2002. Handbook of Thin-Film Deposition Processes and Techniques Principles, Methods, Equipment and Applications, 2nd ed. Norwich, NY Noyes Publications. Brings together information on physical vapor deposition techniques. Available online on Knovel. 

Physical vapor deposition processes constitute only one set of processes available for surface engineering. In order to make the best choice for obtaining the surface properties desired, all of the possible techniques should be considered. Process reproducibihty depends on well-written documentation that is followed. 

Chemical methods of material processing were known for years, existing in parallel with physical and other methods of film deposition. Recent advances in electron microscopy and scanning nanoprobe microscopy (STM, ATM) have revealed that some of the materials produced by the chemical methods have distinctive nanocrystalline structure. Furthermore, due to the achievements of colloid chemistry in the last 20 years, a large variety of colloid nanoparticles have become available for film deposition. This has stimulated great interest in further development of chemical methods as cost-effective alternatives to such physical methods as thermal evaporation magnetron sputtering chemical and physical vapor deposition (CVD, PVD) and molecular beam epitaxy (MBE). 

In thin film technology there is a distinction between physical vapor deposition (PVD) and chemical vapor deposition (CVD), a combination of types is available. All methods work in vacuum. The most important physical processes are evaporation and the sputtering. The material is introduced into the system as a solid (target). With an energy introduced into the target, they resolve atoms and molecules form a layer on the substrate. The layer thickness achieved is in the micrometer range. The layer composition substantially corresponds to that of the target. It can be pure metals, alloys, or dielectrics. 

The polyaromatic mesophase (PA-MP) is a nematic, discotic, chemotropic liquid crystal. Owing to its high density (about 1.5 gcm ), its high carbon yield of about 90 %, and its thermoplasticity, it is unique as a precursor of structure carbons. An important application is the manufacture of high modulus (HM) and ultra-high modulus (UHM) carbon fibers [1]. By alloying with silicon, physical and chemical properties of the materials, such as strength, hardness and oxidation resistance, can be improved. These modified carbons were available by chemical vapor deposition (CVD) processes only up to now. The preparation by liquid phase pyrolysis is novel, economic, and thus opens a completely new field of applications. 

There is little information regarding the surface chemistry involved in the nucleation of amorphous silicon by photo-induced chemical vapor deposition (photo-CVD). The reason seems to be that effective chemical and physical means of detecting a small amount of silicon are hardly available at present. In our laboratory, the initial process of amorphous silicon (a-Si) formation from silanes or disilanes on Si02 substrate by photo-CVD has been studied by a new technique of chemical... 

A number of procedures are available. The simplest is the Industrial process starting from TiOg + C + Ng described in method I. If metallic Ti is available, synthesis from the elements (method II) is recommended. Very pure nitride in rod or wire form, especially well suited for physical measurements, is obtained by vapor deposition (method III). An additional method of lesser importance consists of the reaction between TiCl and NHg (method IV). 

---