Abstract
Single-shot inspection at nanoscale resolution is a problematic challenge for providing on-line inspection of manufacturing techniques such as roll-to-roll processes where the measurand is constantly moving. An example of such a measurement challenge is defect detection on vapor barrier films formed by depositing an aluminum oxide layer several tens of nanometres thick on a flexible polymer substrate. Effective detection and characterisation of defects in this layer requires a single-shot approach with nanometre scale vertical resolution. This paper describes a line-scanning interferometer where a short coherence light source having a 25 nm linewidth source is spatially dispersed across the measurand thus encoding spatial position along a profile by wavelength. Phase shift interferometry (PSI) can be used to decode phase and thus height information, but requires multiple image captures. In order to realise single-shot measurement which is more suitable for online applications, a Fourier transform profilometry (FTP) approach is necessary. This paper explores the implementation of the FTP approach and presents a comparison of the measurement capability of FTP with the previously reported PSI method.
Original language | English |
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Title of host publication | Laser Metrology and Machine Performance XI - 11th International Conference and Exhibition on Laser Metrology, Machine Tool, CMM and Robotic Performance, LAMDAMAP 2015 |
Publisher | euspen |
Pages | 2-7 |
Number of pages | 6 |
ISBN (Electronic) | 9780956679055 |
Publication status | Published - 2015 |
Event | 11th International Conference and Exhibition on Laser Metrology, Coordinate Measuring Machine and Machine Tool Performance - Huddersfield, United Kingdom Duration: 17 Mar 2015 → 18 Mar 2015 Conference number: 11 |
Conference
Conference | 11th International Conference and Exhibition on Laser Metrology, Coordinate Measuring Machine and Machine Tool Performance |
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Abbreviated title | LAMDAMAP 2015 |
Country/Territory | United Kingdom |
City | Huddersfield |
Period | 17/03/15 → 18/03/15 |