Method for etching an electrically conductive layer applied to a substrate

US4969973A · kind A · utility

Assignee

• TEXAS INSTRUMENTS DEUTSCHLAND GMBH · DE

Inventors

• Helmut Rinck · Moosburg an der Isar, DE
• Helmut Endl · Freising, DE

Key dates

• Filing date: Sep 26, 1989
• Grant date: Nov 13, 1990
• Expiry date: Sep 26, 2009

Classification

• Technology area (CPC H): Electricity
• CPC primary: H05K3/068
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

In the etching by means of an etching solution of an electrically conductive layer applied to a substrate the time profile or variation of the diffusion current flowing between the layer to be etched away and the etching solution is measured. The substrate is removed from the etching solution as soon as the diffusion current passes through a steep drop for the second time and assumes a constant value.