Epitaxy is the growth of crystals of one material on the crystal face of another (heteroepitaxy) or the same (homoepitaxy) material, such that the two materials have a defined relative structural orientation. Heteroepitaxy is kind of epitaxy performed with materials that are different from each other. ... Homoepitaxy is kind of epitaxy performed with only one material. ...

Common use in industry is the growth of additional layers of doped silicon on the polished sides of prime silicon wafers, before they are processed into semiconductor devices. This is typical of the power devices, such as those used in pacemakers, vending machine controllers, automobile computers, etc. In semiconductor production, doping refers to the process of intentionally introducing impurities into an intrinsic semiconductor in order to change its electrical properties. ... General Name, Symbol, Number silicon, Si, 14 Chemical series metalloids Group, Period, Block 14, 3, p Appearance dark gray, bluish tinge Atomic mass 28. ... See Wafer (cooking) for the original meaning of the word. ... Derka semiconductor is a material with an electrical conductance that is intermediate between that of an insulator and a conductor. ... A power device is a discrete semiconductor component which is used to control current in electric motors, electronic equipment and cars, and increasingly to regulate and save power in consumer electronic equipment, such as portable appliances. ... The term pacemaker has multiple meanings: In sports, a pacemaker or pacer is a competitor who enters an athletics race with little or no intention of winning, but purely to set a fast pace for other competitors to follow. ...

Commonly, this is accomplished by either single or batch wafer processing using Chemical vapor deposition in an epitaxial reactor, which heats the wafers, etches the exposed face with hydrochloric gas, and then grows the epitaxial layers by flowing a gas mixture that contains silicon and a dopant over the wafer which is so hot that it glows. The gaseous molecules deposit on the face, if done properly, and extend the crystalline structure. DC plasma (violet) enhances the growth of carbon nanotubes in this laboratory-scale PECVD apparatus. ... The chemical substance hydrochloric acid is the aqueous (water-based) solution of hydrogen chloride (HCl) gas. ... A dopant is an impurity element added to a semiconductor lattice in quite low concentrations in order to alter the optical/electrical properties of the semiconductor. ...

Manufacturing issues include control of the amount and uniformity of the deposition's resistivity and thickness, the cleanliness and purity of the surface and the chamber atmosphere, the prevention of the typically much more highly doped substrate wafer's outgassing of dopant to the new layers, imperfections of the growth process, and protecting the surfaces during the manufacture and handling.

Alternatively, molecular beam epitaxy is used. Molecular beam epitaxy, abbreviated MBE, is the deposition of one or more pure materials onto a single crystal wafer, one layer of atoms at a time, under ultra-high vacuum, forming a perfect crystal. ...