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:
Mar. 14, 2000
Filed:
Jul. 16, 1998
Yuichiro Shindo, Toda, JP;
Tsuneo Suzuki, Toda, JP;
Japan Energy Corporation, Tokyo, JP;
Abstract
A process comprises forming ruthenium tetroxide by blowing ozone-containing gas into crude ruthenium powder while hypochlorous acid is being added to the powder, allowing a hydrochloric acid solution to absorb the ruthenium tetroxide, evaporating the solution to dryness, and roasting the RuOCl.sub.3 crystals thus obtained in a hydrogen atmosphere. Thus a high-purity ruthenium material for thin film deposition, typically sputtering targey, is obtained which contains less than 1 ppm each of alkali metal elements, less than 1 ppm each of alkaline earth metal elements, less than 1 ppm each of transition metal elements, less than 10 ppb each of radioactive elements, a total of less than 500 ppm of carbon and gaseous ingredient elements, the material having a purity of ruthenium of at least 99.995% excluding the gaseous ingredient elements.