The Lely method, also known as the Lely process or Lely technique, is a

crystal growth A crystal is a solid material whose constituent atoms, molecules, or ions are arranged in an orderly repeating pattern extending in all three spatial dimensions. Crystal growth is a major stage of a crystallization process, and consists of the a ...

technology used for producing

silicon carbide Silicon carbide (SiC), also known as carborundum (), is a hard chemical compound containing silicon and carbon. A semiconductor, it occurs in nature as the extremely rare mineral moissanite, but has been mass-produced as a powder and crystal sin ...

crystals for the

semiconductor industry The semiconductor industry is the aggregate of companies engaged in the design and fabrication of semiconductors and semiconductor devices, such as transistors and integrated circuits. It formed around 1960, once the fabrication of semiconduct ...

. The patent for this method was filed in the Netherlands in 1954 and in the United States in 1955 by Jan Anthony Lely of

Philips Electronics Koninklijke Philips N.V. (), commonly shortened to Philips, is a Dutch multinational conglomerate corporation that was founded in Eindhoven in 1891. Since 1997, it has been mostly headquartered in Amsterdam, though the Benelux headquarters is ...

. The patent was subsequently granted on 30 September 1958, and was refined by D.R. Hamilton et al. in 1960, and by V.P. Novikov and V.I. Ionov in 1968.

Overview

The Lely method produces bulk silicon carbide crystals through the process of sublimation. Silicon carbide powder is loaded into a graphite

crucible A crucible is a ceramic or metal container in which metals or other substances may be melted or subjected to very high temperatures. While crucibles were historically usually made from clay, they can be made from any material that withstands te ...

, which is purged with Argon gas and heated to approximately . The silicon carbide near the outer walls of the crucible sublimes and is deposited on a graphite rod near the center of the crucible, which is at a lower temperature. Several modified versions of the Lely process exist, most commonly the silicon carbide is heated from the bottom end rather than the walls of the crucible, and deposited on the lid. Other modifications include varying the temperature,

temperature gradient A temperature gradient is a physical quantity that describes in which direction and at what rate the temperature changes the most rapidly around a particular location. The temperature gradient is a dimensional quantity expressed in units of degree ...

, Argon pressure, and geometry of the system. Typically, an

induction furnace An induction furnace is an electrical furnace in which the heat is applied by induction heating of metal. Induction furnace capacities range from less than one kilogram to one hundred tons, and are used to melt iron and steel, copper, aluminum ...

is used to achieve the required temperatures of .

References

Crystallography Materials science Thin film deposition {{crystallography-stub

Overview

See also

References