In this study, we demonstrate the conformal deposition of SiO2 and TiO2 thin films using plasma-enhanced Spatial ALD. Despite atmospheric-pressure conditions, high-aspect-ratio structures can be conformally coated using subsecond plasma exposure times. Additionally, we determine the radical recombination probability and draw comparisons with low-pressure PE-ALD. The research article is open to access here.

Authors

Mike L. van de Poll, Hardik Jain, James N. Hilfiker, Mikko Utriainen, Paul Poodt,
Wilhelmus M. M. Kessels, and Bart Macco

Abstract

Atmospheric-pressure spatial atomic layer deposition (s-ALD) has emerged as a scalable deposition technique combining the advantages
of ALD with high deposition rates, suitable for low-cost and high-volume applications. There is a growing interest in atmosphericpressure plasma-enhanced spatial ALD (PE-s-ALD), e.g., to allow for deposition at reduced temperatures or for materials that are otherwise difficult to prepare by thermal ALD. For low-pressure PE-ALD, conformal films on high aspect ratio features have been achieved despite plasma radical recombination, and the aspects influencing conformality are fairly well understood. This work addresses surface recombination and conformality for atmospheric-pressure PE-s-ALD films. We demonstrate that conformality can be achieved for SiO2 and TiO2 films deposited by atmospheric-pressure PE-s-ALD inside high-aspect-ratio trenches with short plasma exposure times. Using plasma exposure of 0.73 s results in conformal SiO2 and TiO2 films in structures with aspect ratios of 74 and 219, respectively. Additionally, the recombination probabilities of oxygen radicals at atmospheric pressure are extracted to be 4 x 10^-4 for SiO2 and 6 x 10^-5 for TiO2. These results demonstrate that atmospheric-pressure PE-s-ALD can be used for conformal and high-speed depositions on 3D substrates. VC 2023 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). https://doi.org/10.1063/5.0168768

About SparkNano

SparkNano develops and supplies Spatial Atomic Layer Deposition equipment for energy, OLED and related applications. SparkNano was first founded in 2018 as a spin-off of TNO (the Netherlands Organization of Applied Scientific Research). The company’s products enable its customers to seamlessly scale from lab-to-fab. Next to the high-quality equipment, an experienced team also supports in process development and optimization, provides application support and yield & and performance management. SparkNano is located in the Brainport ecosystem in Eindhoven.