Process for the electrolytic deposition of metal layers

US6099711A · kind A · utility

Assignee

• Atotech Deutschland GmbH & Co. KG · DE

Inventors

• Wolfgang Dahms · Berlin, DE
• Heinrich Meyer · Berlin, DE
• Stefan Kretschmer · Berlin, DE

Key dates

• Filing date: Apr 23, 1998
• Grant date: Aug 8, 2000
• Expiry date: Apr 23, 2018

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S205/92
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

The invention relates to a method for the electrolytic deposition of metal coatings, in particular of copper coatings with certain physical-mechanical and optical properties and uniform coating thickness. According to known methods using soluble anodes and applying direct current, only uneven metal distribution can be attained on complex shaped workpieces. By using a pulse current or pulse voltage method, the problem of the coatings being of varying thickness at various places on the workpiece surfaces can indeed be reduced. However, the further problem of the geometric ratios being changed continuously during the depositing process by dissolving of the anodes is not resolved thus. This can be avoided by using insoluble anodes. In order to guarantee sufficient stability of the anodes and a bright coating even at those points on the workpiece surfaces, onto which the metal is deposited with high current density, it is essential to add compounds of an electrochemically reversible redox system to the depositing solution.