Microwave measuring and apparatus for contactless non-destructive testing of photosensitive materials

US4704576A · kind A · utility

Assignee

• Hahn-Meitner-Institut fur Kernforschung Berlin GmbH · DE

Inventors

• Helmut Tributsch · Berlin, DE
• Gerhard Beck · Berlin, DE
• Marinus Kunst · Berlin, DE

Key dates

• Filing date: Feb 28, 1985
• Grant date: Nov 3, 1987
• Expiry date: Feb 28, 2005

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N22/00
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

Variations in parameters of a waveguide system caused by an excitation of charge carriers of a specimen to be measured and positioned in a microwave field, give definite information on the material properties of the specimen without having to destroy, or even contact the specimen. Irradiation with a sharply focused photon or electron beam of a surface spot having a diameter of about 0.1 to 10.0 micrometers, and displacing of this light spot across the surface of the specimen, with the displacement increments of the specimen within the cross sectional area of a waveguide being of the order of magnitude of micrometers, surface structures such as ground boundaries, steps in stratified-lattice crystals, formation defects, destroyed surface areas, etc., can be detected in photosensitive semiconductor layers with a high resolution.