Enabling rotary atomic layer deposition for optical applications

authored by
Leif Kochanneck, John Rönn, Andreas Tewes, Gerd Albert Hoffmann, Sauli Virtanen, Philipp Maydannik, Sami Sneck, Andreas Wienke, Detlev Ristau
Abstract

Atomic layer deposition (ALD) has been proven as an excellent method for depositing high-quality optical coatings due to its outstanding film quality and precise process control. Unfortunately, batch ALD requires time-consuming purge steps, which leads to low deposition rates and highly time-intensive processes for complex multilayer coatings. Recently, rotary ALD has been proposed for optical applications. In this, to the best of our knowledge, novel concept, each process step takes place in a separate part of the reactor divided by pressure and nitrogen curtains. To be coated, substrates are rotated through these zones. During each rotation, an ALD cycle is completed, and the deposition rate depends primarily on the rotation speed. In this work, the performance of a novel rotary ALD coating tool for optical applications is investigated and characterized with SiO2 and Ta2O5 layers. Low absorption levels of <3.1 ppm and <6.0 ppm are demonstrated at 1064 nm for around 186.2 nm thick single layers of Ta2O5 and 1032 nm SiO2, respectively. Growth rates up to 0.18 nm/s on fused silica substrates were achieved. Furthermore, excellent non-uniformity is also demonstrated, with values reaching as low as ±0.53% and ±1.07% over an area of 135 × 60 mm for Ta2O5 and SiO2, respectively.

Organisation(s)
PhoenixD: Photonics, Optics, and Engineering - Innovation Across Disciplines
Institute of Quantum Optics
External Organisation(s)
Laser Zentrum Hannover e.V. (LZH)
Beneq Oy
Type
Article
Journal
Applied optics
Volume
62
Pages
3112-3117
No. of pages
6
ISSN
1559-128X
Publication date
17.04.2023
Publication status
Published
Peer reviewed
Yes
ASJC Scopus subject areas
Atomic and Molecular Physics, and Optics, Engineering (miscellaneous), Electrical and Electronic Engineering
Electronic version(s)
https://doi.org/10.1364/AO.477448 (Access: Closed)