Process for making a crystalline solid-solution powder with low electrical resistance

US6030507A · kind A · utility

Assignee

• W.C. Heraeus GmbH & Co. KG · DE

Inventors

• David Francis Lupton · Gelnhausen, DE
• Jorg Schielke · Bruchköbel, DE
• Marek Gorywoda · Hanau, DE
• Bernard Serole · Romans-sur-Isère, FR
• Friedhold Scholz · Rodenbach, DE

Key dates

• Filing date: May 14, 1998
• Grant date: Feb 29, 2000
• Expiry date: May 14, 2018

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C01P2006/40
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

A process for making a crystalline solid-solution powder which involves reacting at least two reactants in a plasma arc of a plasma chamber and blast-cooling the resultant product in a high velocity gas stream to form the powder. The first reactant is a molten metal alloy and the second reactant is a gas. The reaction is carried out in a plasma arc and the products rapidly cooled by a gas stream acting at the outlet opening of the plasma chamber. The crystalline solid-solution powder formed by the process has a low electrical resistivity. If an indium-tin alloy is used as the first reactant and oxygen as the second reactant, there is obtained an indium-tin-oxide (ITO) crystalline solid-solution powder which, when compacted to 40% of its theoretical density, has an electrical resistivity in the range of about 2 .OMEGA.cm. This ITO crystalline solid-solution powder is particularly suitable for preparing an ITO target, with high electrical conductivity and thus high achievable sputtering rates.