====[[Atomic_layer_deposition|Atomic Layer Deposition (ALD)]]====
Atomic layer deposition (ALD) is a type of chemical vapor deposition (CVD) where the reactions are limited to the surface of the object being coated. Instead of flowing two or more gasses into the chamber and letting them react on or near the surface of the substrate as in CVD, in ALD the individual chemical components are introduced to the deposition chamber one at a time. Because the reaction is surface-limited, ALD creates extremely conformal films with well controlled thickness. Unfortunately, in order to limit CVD in the chamber, gasses must be pumped out completely between each dose, making the process very slow and only useful for very thin films.
Electron beam evaporation (e-beam evaporation) is a form of physical vapor deposition in which a target anode is bombarded with an electron beam given off by a tungsten filament under high vacuum. The accelerated electrons strike the target and melt/sublimate the material 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.
Sputter deposition is a physical vapor deposition method of thin film deposition in which a high-purity source material (called a cathode or target) is subjected to a gas plasma (typically argon). The energetic atoms in this gas plasma collide with the target material and knock off source atoms which then travel to the substrate and condense into a thin film.
====[[Wet etching|Wet etching]]====
Wet etching can be used to etch aluminum using [[Aluminum Etch]]
*'''Etch rates for micromachining processing''' https://ieeexplore.ieee.org/abstract/document/546406
*'''Etch rates for micromachining processing-Part II''' https://ieeexplore.ieee.org/abstract/document/1257354