The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 26, 2014
Filed:
Feb. 15, 2005
Akira Noda, Kitaibaraki, JP;
Ryuichi Hirano, Kitaibaraki, JP;
Akira Noda, Kitaibaraki, JP;
Ryuichi Hirano, Kitaibaraki, JP;
Nippon Mining & Metals Co., Ltd., Tokyo, JP;
Abstract
A method for producing a low-dislocation InP single crystal suitably used for an optical device such as a semiconductor laser, and the low-dislocation InP single crystal wafer are provided. In a liquid-encapsulated Czochralski method in which a semiconductor raw material and an encapsulant are contained in a raw material melt containing part comprising a cylindrical crucible having a bottom, the raw material containing part is heated to melt the raw material, and a seed crystal is brought into contact with a surface of a melt of the raw material in a state of being covered with the encapsulant to grow a crystal while the seed crystal is raised; a crystal shoulder part is grown from the seed crystal by setting a temperature gradient in a crystal growth direction to 25° C./cm or less and setting a temperature-fall amount to 0.25° C./hr or more. Thus, an iron-doped or undoped InP single crystal wafer in which an area having a dislocation density of 500/cmor less occupies 70% or more is realized.