Abstract

Structural, optical, and mechanical properties of Al2O3, SiO2, and HfO2 materials prepared by plasma-enhanced atomic layer deposition (PEALD) were investigated. Residual stress poses significant challenges for optical coatings since it may lead to mechanical failure, but in-depth understanding of these properties is still missing for PEALD coatings. The tensile stress of PEALD alumina films decreases with increasing deposition temperature and is approximately 100 MPa lower than the stress in thermally grown films. It was associated with incorporation of -OH groups in the film as measured by infrared spectroscopy. The tensile stress of hafnia PEALD layers increases with deposition temperature and was related to crystallization of the film. HfO2 nanocrystallites were observed even at 100°C deposition temperature with transmission electron microscopy. Stress in hafnia films can be reduced from approximately 650 MPA to approximately 450 MPa by incorporating ultrathin Al2O3 layers. PEALD silica layers have shown moderate stress values and stress relaxation with the storage time, which was correlated to water adsorption. A complex interference coating system for a dichroic mirror (DCM) at 355 nm wavelength was realized with a total coating thickness of approximately 2 μm. Severe cracking of the DCM coating was observed, and it propagates even into the substrate material, showing a good adhesion of the ALD films. The reflectance peak is above 99.6% despite the mechanical failure, and further optimization on the material properties should be carried out for demanding optical applications.

© 2016 Optical Society of America

Full Article  |  PDF Article
OSA Recommended Articles
Research on the mechanical stability of high laser resistant coatings on lithium triborate crystal

Jinlong Zhang, Xiaoqing Bu, Bin Ma, Hongfei Jiao, Xinbin Cheng, and Zhanshan Wang
Appl. Opt. 56(4) C117-C122 (2017)

Mixed oxide coatings for optics

Olaf Stenzel, Steffen Wilbrandt, Mark Schürmann, Norbert Kaiser, Henrik Ehlers, Mathias Mende, Detlev Ristau, Stefan Bruns, Michael Vergöhl, Markus Stolze, Mario Held, Hansjörg Niederwald, Thomas Koch, Werner Riggers, Peer Burdack, Günter Mark, Rolf Schäfer, Stefan Mewes, Martin Bischoff, Markus Arntzen, Frank Eisenkrämer, Marc Lappschies, Stefan Jakobs, Stephan Koch, Beate Baumgarten, and Andreas Tünnermann
Appl. Opt. 50(9) C69-C74 (2011)

Stress compensation in hafnia/silica optical coatings by inclusion of alumina layers

J. B. Oliver, P. Kupinski, A. L. Rigatti, A. W. Schmid, J. C. Lambropoulos, S. Papernov, A. Kozlov, C. Smith, and R. D. Hand
Opt. Express 20(15) 16596-16610 (2012)

References

You do not have subscription access to this journal. Citation lists with outbound citation links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Figures (16)

You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Tables (5)

You do not have subscription access to this journal. Article tables are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Equations (2)

You do not have subscription access to this journal. Equations are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Metrics

You do not have subscription access to this journal. Article level metrics are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription