TY - GEN

T1 - Study of rotary atomic layer deposition for optical applications

AU - Kochanneck, Leif

AU - Tewes, Andreas

AU - Hoffmann, Gerd Albert

AU - Niiranen, Kalle

AU - Rönn, John

AU - Velasco, Hector

AU - Sneck, Sami

AU - Wienke, Andreas

AU - Ristau, Detlev

N1 - Funding Information: This work was supported by the European Regional Development Fund ZW 2-80147672 and also by the German Federal Ministry of Education and Research in the research project INTEGRA 01QE2032B. The authors would like to thank the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) for funding this work under Germany’s Excellence Strategy within the Cluster of Excellence PhoenixD (EXC 2122, Project ID 390833453).

PY - 2022/3/5

Y1 - 2022/3/5

N2 - Atomic layer deposition (ALD) has been proven as an excellent method for coating high quality optical films due to its outstanding film quality and precise process control. Unfortunately, batch ALD requires time-consuming purge steps, which lead to low deposition rates and highly time-intensive processes for complex multilayer coatings. Recently, rotary ALD came in focus for optical applications. In this novel process concept, each process step takes place in a separate part of the reactor divided by pressure and nitrogen curtains. The substrates to-be-coated are rotated through these zones. During each rotation, an ALD cycle is completed, thus the deposition rate is mainly dependent on the rotation speed. In this study, 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 for 200 nm thick single layer of Ta2O5 and 6.0 ppm for 1032 nm thick single layer of SiO2 are demonstrated at 1064 nm, respectively, with growth rates up to 0.18 nm/s on fused silica substrates. Furthermore, excellent uniformity is also demonstrated with non-uniformity values reaching as low as 1.55 % and 2.71% for Ta2O5 and SiO2, respectively, over 120 mm on silicon wafers. Seven substrates up to a diameter of 200 mm can be coated in each run. Further investigations on uniformity improvements and multilayer coatings are currently ongoing.

AB - Atomic layer deposition (ALD) has been proven as an excellent method for coating high quality optical films due to its outstanding film quality and precise process control. Unfortunately, batch ALD requires time-consuming purge steps, which lead to low deposition rates and highly time-intensive processes for complex multilayer coatings. Recently, rotary ALD came in focus for optical applications. In this novel process concept, each process step takes place in a separate part of the reactor divided by pressure and nitrogen curtains. The substrates to-be-coated are rotated through these zones. During each rotation, an ALD cycle is completed, thus the deposition rate is mainly dependent on the rotation speed. In this study, 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 for 200 nm thick single layer of Ta2O5 and 6.0 ppm for 1032 nm thick single layer of SiO2 are demonstrated at 1064 nm, respectively, with growth rates up to 0.18 nm/s on fused silica substrates. Furthermore, excellent uniformity is also demonstrated with non-uniformity values reaching as low as 1.55 % and 2.71% for Ta2O5 and SiO2, respectively, over 120 mm on silicon wafers. Seven substrates up to a diameter of 200 mm can be coated in each run. Further investigations on uniformity improvements and multilayer coatings are currently ongoing.

KW - atomic layer deposition

KW - optical coating

KW - rotatory ALD

KW - thin film

UR - http://www.scopus.com/inward/record.url?scp=85131224280&partnerID=8YFLogxK

U2 - 10.1117/12.2612173

DO - 10.1117/12.2612173

M3 - Conference contribution

AN - SCOPUS:85131224280

T3 - Proceedings of SPIE - The International Society for Optical Engineering

BT - Oxide-based Materials and Devices XIII

A2 - Rogers, David J.

A2 - Teherani, Ferechteh H.

PB - SPIE

T2 - Oxide-based Materials and Devices XIII 2022

Y2 - 20 February 2022 through 24 February 2022

ER -