Epitaxy is an important technique in crystallography where natural or artificial crystals are grown on a crystalline substrate; the underlying substrate acts as a seed crystal and determines the orientation of the crystals which grow upon it.

What is Epitaxy?

Derived from the Greek epi, meaning above, and taxis; an ordered manner, the process results in the formation of one or several crystalline thin films that may be of the same or different chemical compositions and structure as the substrate. The deposited film locks Into one or more crystallographic orientations with respect to the substrate crystal; and the resulting epitaxial film or layer has a particular registry or location relative to the underlying layer.

Epi technology is used in semiconductor fabrication to create a perfect crystalline foundation layer on which to build a semiconductor device, to deposit a crystalline film with engineered electrical properties, or to alter mechanical attributes of an underlayer in a way that improves its electrical conductivity. This last application is known as strain engineering in which the epitaxial film results in compressive or tensile strain in the lattice of the transistor channel. epi technologies address all of these applications, producing highly uniform films with precise placement of dopant atoms, exceptionally low defect levels, and the capability for selective deposition

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