Journal article
Three-dimensional nanometrology of microstructures by replica molding and large-range atomic force microscopy
DTU Danchip, Technical University of Denmark1
Department of Physics, Technical University of Denmark2
Neutrons and X-rays for Materials Physics, Department of Physics, Technical University of Denmark3
Surface Physics and Catalysis, Department of Physics, Technical University of Denmark4
Department of Micro- and Nanotechnology, Technical University of Denmark5
Silicon Microtechnology, Department of Micro- and Nanotechnology, Technical University of Denmark6
DFM - Dansk Fundamental Metrologi A/S7
We have used replica molding and large-range atomic force microscopy to characterize the threedimensional shape of high aspect ratio microstructures. Casting inverted replicas of microstructures using polydimethylsiloxane (PDMS) circumvents the inability of AFM probes to measure deep and narrow cavities.
We investigated cylindrical deep reactive ion etched cavities in silicon wafers and determined the radius of curvature (ROC) of the sidewalls as a function of depth. Statistical analysis verified the reliability and reproducibility of the replication procedure. The mean ROC was determined as (6.32 ± 0.06) lm, i.e., with 1% accuracy, while the ROC linearly increases by (0.52 ± 0.03) lm from the top to the bottom of the sidewalls.
Nanometer sized surface defects are also well replicated. In addition, the method allows combining multiple features from differently processed wafers into a single sample, accelerating characterization in process optimization tasks. To access the sidewall shape samples needed to be cleaved. The method was applied to study X-ray refractive optics, whose performance is crucially affected by their three dimensional shapes.
Language: | English |
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Year: | 2015 |
Pages: | 6-11 |
ISSN: | 18735568 and 01679317 |
Types: | Journal article |
DOI: | 10.1016/j.mee.2014.11.026 |
ORCIDs: | Stöhr, Frederik , Michael-Lindhard, Jonas , Poulsen, Henning Friis , Hübner, Jörg , Hansen, Ole and Jensen, Flemming |