Etching solution

US5462640A · kind A · utility

Assignee

• Kernforschungszentrum Karlsruhe GmbH · DE

Inventors

• Walter Stark · Baltimore, US
• Robert Ruprecht · Walzbachtal, DE

Key dates

• Filing date: Dec 22, 1992
• Grant date: Oct 31, 1995
• Expiry date: Dec 22, 2012

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C23F1/44
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

An etching solution for etching away a metal layer from a substrate includes a hydrogen-containing compound that dissolves the metal layer while developing hydrogen; and a nitrosubstituted organic compound having a nitro group which is easily hydratable and which has at least a 1/3 nitro group equivalent per mole of the hydrogen developed by reaction between the hydrogen-containing compound and the metal layer until the metal layer is dissolved completely. A method for etching employs the etching solution into which the substrate is immersed. The process of preventing the release of hydrogen gas during the etching away of a metal layer from a substrate is taught and includes employing an etching solution containing one of an acid or a highly basic metal hydroxide; and adding to the etching solution an organic nitro compound which is soluble in water and which is easily hydratable.