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:
May. 12, 2020
Filed:
Jun. 08, 2016
Sumitomo Metal Mining Co., Ltd., Tokyo, JP;
Tomio Kajigaya, Ome, JP;
SUMITOMO METAL MINING CO., LTD., Tokyo, JP;
Abstract
To provide a method of producing a lithium niobate (LN) substrate which allows treatment conditions regarding a temperature, a time, and the like to be easily managed and in which an in-plane distribution of a volume resistance value is very small, and also variations in volume resistivity are small among substrates machined from the same ingot. A method of producing an LN substrate by using an LN single crystal grown by the Czochralski process, in which a lithium niobate single crystal having a Fe concentration of 50 mass ppm or more and 2000 mass ppm or less in the single crystal and being in a form of an ingot is buried in an Al powder or a mixed powder of Al and AlO, and heat-treated at a temperature of 450° C. or more and less than 660° C., which is a melting point of aluminum, to produce a lithium niobate single crystal substrate having a volume resistivity controlled to be within a range of 1×10Ω·cm or more to 2×10Ω·cm or less.