Test device for testing a bonding layer between wafer-shaped samples and test process for testing the bonding layer

US9494409B2 · kind B2 · utility

Assignee

• PRECITEC OPTRONIK GMBH · DE

Inventors

• Martin Schönleber · Aschaffenburg, DE
• Berthold Michelt · Wiesbaden, DE

Key dates

• Filing date: Jun 15, 2012
• Grant date: Nov 15, 2016
• Expiry date: Jun 24, 2032

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N2021/8438
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

The invention relates to a test device for testing a bonding layer between wafer-shaped samples and a test process for testing the bonding layer. The test device comprises a measuring head for an OCT process that is configured to direct an optical measuring beam at a composite comprising at least two wafer-shaped samples with a bonding layer positioned between them. An optical beam splitter is configured to divert an optical reference beam as a reference arm for distance measurements. An evaluation unit is configured to evaluate layer thickness measurements without a reference arm and distance measurements with a reference arm. An optical switch device is configured to connect and disconnect the reference arm.