Creator:
Date Created:
Place Created:
Keywords:Calvin H. Carter,February 17, 1998
Context:Growth of colorless silicon carbide crystals
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Growth of colorless silicon carbide crystals
US5718760: Growth of colorless silicon carbide crystals
Inventor(s): Carter; Calvin H., Cary, NC
Tsvetkov; Valeri F., Durham, NC Glass; Robert C., Chapel Hill, NC
Applicant(s): Cree Research, Inc., Durham, NC
Issued/Filed Dates: Feb. 17,1998 / Feb. 5, 1996
Application Number: US1996000596526
IPC Class: C30B 029/36:
Class: 117/084: 117/089: 117/093: 117/102:
Field of Search: 117/84,89,93,95,102,937 423/446 437/22,100
Abstract: Large single crystals of silicon carbide are grown in a furnace sublimation system. The crystals are grown with compensating levels of p-type and n-type dopants (i.e., roughly equal to levels of the two dopants) in order to produce a crystal that is essentially colorless. The crystal may be cut and fashioned into synthetic gemstones having extraordinary toughness and hardness, and a brilliance meeting or exceeding that of diamond.
Attorney, Agent, or Summa, Patent Attorney; Philip;
Firm:
Primary/Assistant Garrett; Felisa;
Examiners:
U.S. References:
Patent	Inventor	Issued	Title
US4966860	Suzuki et al.	10/1990	Process for producinq a SiC semiconductor device
			
US5030580	Furukawa et al.	7/1991	Method for producing a silicon carbide semiconductor device
			
			
US5433167	Furukawa et al.	7/1995	Method of producinq silicon-carbide sinqle crystals by sublimation recrystallization process using a seed crystal
			
			
First Claim: Show all 11 claims
That which is claimed:
1. A method of producing a colorless single crystal of silicon carbide comprising growing a single crystal of silicon carbide by a sublimation technique while introducing compensated levels of p-type and n-type dopants into a crystal lattice structure.
Foreign References: none
Other References.	. Introduction to Ceramics, W. D. Kingery et al., Second Edition, John
Wiley & Sons, pp. 676-679. • Optical and Electronic Properties of SiC, W. H. Choyke, The Physics and Chemistry of Carbides, Nitrides and Borides, Manchester, England, Sep. 1989, pp. 1-25.