Method and apparatus for etching substrates with a magnetic-field supported low-pressure discharge

US4911784A · kind A · utility

Assignee

• Leybold GmBH · DE

Inventors

• Bernd Hensel · Eschborn, DE
• Dieter Hofmann · Augsburg, DE

Key dates

• Filing date: Dec 23, 1988
• Grant date: Mar 27, 1990
• Expiry date: Dec 23, 2008

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01J2237/334
• WIPO field: Electrical machinery, apparatus, energy
• WIPO sector: Electrical engineering

Abstract

An etching method whereby a sufficiently high etching rate is attained, in a uniform surface treatment that is very gentle on projecting edges of the substrates. Also the substrates are held at or brought to a sufficiently high temperature by the etching process. The method for etching substrates with a magnetic-field supported low-pressure discharge is characterized in that the magnetic field is decoupled from the substrates such that the magnetic field strength at the substrates is less than 6000 A/m. In the space between the substrates and the magnet system at least one electron emitter is disposed at a location at which a magnetic field strength is present that is greater than the field strength at the substrates but equal to or less than 12,000 A/m. On the side of the substrates facing away from the at least one electron emitter, at least one anode is disposed with an anode potential of +10 to +250 V with respect to ground. An etching potential between -100 V and -1000 V with respect to ground is applied to the substrates. The ratio of the gaps between the substrates and the surfaces of the substrates projected onto a projection plane carried through the gaps amounts to at lea…