Atomic Layer Deposition (ALD) is a type of chemical vapor deposition (CVD), in which a thin film is obtained by chemical reaction of the gas compound of the film material to generate a solid substance and deposit on the substrate. The difference from traditional CVD is that in the ALD reaction process, only one kind of precursor is introduced at a time. Until the surface is saturated with adsorption or the reaction produces the required film specification, the excessive precursors and by-products produced by the reaction will be flushed with inert gas Ar or N2 (purge), repeated hundreds of times to deposit reaction compounds of tens of nanometers.
Because of its ability to grow with the three-dimensional shape of the substrate, the film prepared by ALD technology has the characteristics of high density, high thickness uniformity, high step coverage, low temperature process and atomic-level precision control of thickness, which can accurately control the uniformity of the film thickness.
In addition to coating ultra-thin high-dielectric materials, it can also provide hole-filling capabilities for tiny circuit structures. Applications include semiconductor integrated circuits, micro-electro-mechanics, thin-film transistors, OLED displays, and component packaging.