Imaging Mueller matrix ellipsometry setup for optical nanoform metrology

Tim Käseberg,Jana Grundmann,Johannes Dickmann,Stefanie Kroker,Bernd Bodermann,H Michinel,O Frazao,M.F Costa

doi:10.1051/epjconf/202023806006

Tim Käseberg, Jana Grundmann + Show 6 more

Open Access

https://doi.org/10.1051/epjconf/202023806006

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Abstract

We designed, realized, and characterised an imaging Mueller matrix ellipsometry setup for the pixelwise measurement of the Mueller matrices in microscope images. Our setup is capable of performing measurements in reflection as well as in transmission in a broad range of angles of incidence for wavelengths between 400 nm and 700 nm. We compared measurements of specially designed nanostructured samples with AFM and SEM measurements as well as with numerical simulations using the finite element method.

Highlights

The reliable production of structures at the nanometre scale remains a crucial issue in modern nanotechnology and it relies on the precise characterisation of the structures using fast and non-invasive measurement techniques
The illumination arm consists of a white light LED, limited to single wavelengths using bandpass filters, as well as a collimating lens and a polarisation state generator (PSG) system
We examine plasmonic lenses that can be used as resolution enhancement devices

Summary

Introduction

The reliable production of structures at the nanometre scale remains a crucial issue in modern nanotechnology and it relies on the precise characterisation of the structures using fast and non-invasive measurement techniques. Given usually large beam sizes in common ellipsometric setups, these areas rarely fall below several 10 μm in diameter, whereas applications such as in semiconductor industries deal with much smaller measurement targets. This limitation can be overcome by upgrading the classic ellipsometric setup with an imaging system. The Mueller matrix of the sample can be determined for each pixel in an image, allowing for evaluations of sample features within much smaller interaction areas than the illumination area This can be complemented by the investigation of off-diagonal elements of the Mueller matrix which have been shown to provide additional information about subwavelength sized features [3].

Experimental Setup

First Measurements