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)