Robinson, A D; Leach, R K (2008) Overview of tomography techniques to measure wafer thickness in MEMS structures. NPL Report. ENG 8

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Abstract

This report investigates possible metrology solutions to the industrial requirement for the measurement of the wafer thickness and internal structure of MEMS sensors. A range of optical and electrical techniques were reviewed and the report recommends optical coherence tomography as the most suitable technique. Optical coherence tomography is considered from a theoretical perspective and a range of system designs and commercially available instruments are discussed, including some images of a MEMS sensor as proof of concept. Finally recommendations are made for further research in image processing in order to obtain sub-micrometre axial resolution for MEMS measurement.

Item Type:	Report/Guide (NPL Report)
NPL Report No.:	ENG 8
Keywords:	MEMS, tomography, thickness
Subjects:	Engineering Measurements Engineering Measurements > Dimensional
Last Modified:	02 Feb 2018 13:15
URI:	https://eprintspublications.npl.co.uk/id/eprint/4207