Electron Beam Physical Vapor Deposition (EBPVD) is a form of physical vapor deposition in which a target anode is bombarded with an electron beam given off by a charged tungsten filament under high vacuum. The electron beam causes atoms from the target to transform into the gaseous phase. These atoms then precipitate into solid form, coating everything in the vacuum chamber (within line of sight) with a thin layer of the anode material. It yields a high deposition rate from few  nm/min to 100 nm / min at relatively low substrate temperatures, with very high material utilization efficiency. The deposition rate in this process can be as low as 1 nm per minute to as high as few micrometers per minute. Due to the very high deposition rate, this process has potential industrial application for wear resistant and thermal barrier coatings in aerospace industries, hard coatings for cutting and tool industries, and electronic and optical films for semiconductor industries and thin film solar applications. A potential problem is that filament degradation in the electron gun results in a nonuniform evaporation rate. 

Molecular beam epitaxy (MBE) is one of several methods of depositing single crystals. Molecular beam epitaxy takes place in high vacuum or ultrahigh vacuum (10−10 Torr). The most important aspect of MBE is the very small deposition rates (typically < 1 nm per sec) allows the films to grow epitaxially. These deposition rates require proportionally better vacuum to achieve the same impurity levels as other deposition techniques. The absence of carrier gases as well as the ultra high vacuum environment result in the highest achievable purity of the grown films. Such layers are now a critical part of many modern semiconductor devices, including semiconductor lasers and light emitting diodes.

Chemical vapor deposition (CVD) is a widely used materials-processing technology. CVD involves flowing a precursor gas or gases into a chamber containing one or more pre heated objects to be coated (or substrates). Chemical reactions occur on and near the hot surfaces (substrates), resulting in the deposition of a thin film on the surface. This is accompanied by the production of chemical by-products that are exhausted out of the chamber along with unreacted precursor gases. It is done in hot-wall reactors and cold-wall reactors, at sub-torr total pressures to above-atmospheric pressures, with and without carrier gases, and at temperatures typically ranging from 200-1600°C. There are also a variety of enhanced CVD processes, which involve the use of plasmas, ions, photons, lasers, hot filaments, or combustion reactions to increase deposition rates and/or lower deposition temperatures.                                            

CVD has a number of advantages as a method for depositing thin films. One of the primary advantages is that CVD films are generally quite conformal. Films can be applied to elaborately shaped pieces, including the insides and undersides of features, and that high-aspect ratio holes and other features can be completely filled. In contrast, physical vapor deposition (PVD) techniques, such as sputtering or evaporation, generally require a line-of-sight between the surface to be coated and the source. Another advantage of CVD is that, in addition to the wide variety of materials that can be deposited, they can be deposited with very high purity. Other advantages include relatively high deposition rates, and the fact that CVD often doesn’t require as high a vacuum as PVD processes.

CVD also has a number of disadvantages. CVD precursors can also be highly toxic (Ni(CO)4), explosive (B2H6), or corrosive (SiCl4). The byproducts of CVD reactions can also be hazardous (CO, H2, or HF). Some of these precursors, especially the metal-organic precursors, can also be quite costly. The other major disadvantage is the fact that the films are usually deposited at elevated temperatures. This puts some restrictions on the kind of substrates that can be coated. More importantly, it leads to stresses in films deposited on materials with different thermal expansion coefficients, which can cause mechanical instabilities in the deposited films.