Method of measuring the contact angle of wetting liquid on a solid surface

US5080484A · kind A · utility

Assignee

• TEXAS INSTRUMENTS DEUTSCHLAND GMBH · DE

Inventors

• Helmut Schneider · Hersbruck, DE
• Helmut Rinck · Moosburg an der Isar, DE

Key dates

• Filing date: Apr 28, 1989
• Grant date: Jan 14, 1992
• Expiry date: Apr 28, 2009

Classification

• Technology area (CPC G): Physics
• CPC primary: G01B11/26
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

The invention relates to a method of measuring the contact angle of wetting liquids on a solid surface with which a high measuring accuracy and better reproduceability of the measurement results is achieved. The method resides in that a laser beam is directed onto the interface line between the liquid and the plane solid surface in such a manner that a first part of the laser beam is reflected by the solid surface and a second part by the liquid surface. The second partial beam is used as measuring beam by determining the angle (.delta.) made between the measuring beam and the solid surface, said angle being in a fixed geometrical relationship to the contact angle (r). The contact angles which can be determined very accurately with this measuring method provide information on wetting properties of materials, the exact knowledge of which is of great significance for example for semiconductor fabrication.