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

crystal growth Crystal growth is a major stage of a crystallization, crystallization process, and consists of the addition of new atoms, ions, or polymer strings into the characteristic arrangement of the crystalline lattice. The growth typically follows an ini ...

technology used for producing

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

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. Its roots can be traced to the invention of the transistor ...

. 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. (), simply branded Philips, is a Dutch multinational health technology company that was founded in Eindhoven in 1891. Since 1997, its world headquarters have been situated in Amsterdam, though the Benelux headquarter ...

. The patent was subsequently granted on 30 September 1958, then 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 container in which metals or other substances may be melted or subjected to very high temperatures. Although crucibles have historically tended to be made out of clay, they can be made from any material that withstands temperat ...

, which is purged with

argon Argon is a chemical element; it has symbol Ar and atomic number 18. It is in group 18 of the periodic table and is a noble gas. Argon is the third most abundant gas in Earth's atmosphere, at 0.934% (9340 ppmv). It is more than twice as abu ...

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 spatial gradient is a vector quantity with Dimensional analysis, ...

, 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, aluminu ...

is used to achieve the required temperatures of .

References

Crystallography Materials science Thin film deposition {{crystallography-stub

Overview

See also

References