Visit our booth and poster at ALD/ALE 2022

This year Dr. Chanel Linnane is representing Impedans at the 22nd international conference on Atomic Layer Deposition. She will be answering questions on how to characterise the plasmas driving ALD processes and how to monitor process repeatability in real-time. She will also be presenting a poster in the “ALD for Manufacturing” session with examples of how plasma measurement has helped understand and develop ALD processes.

The poster is titled “How to improve control of plasma assisted ALD/ALE processes by accurate measurement of ion flux, energy distributions and ion-neutral ratios in commercial plasma tools using RFEAs”.

Click here to book a meeting with Dr Chanel Linnane.



Plasma assisted ALD/ALE processes have demonstrated potential advantages for next-generation semiconductor processes including high-k, multi-patterning and fin doping. However, with more spatially demanding structures and ever-shrinking device dimensions, the need for controllable and optimized plasma processes has never been greater. To fulfil this need, Impedans automated advanced Retarding Field Energy Analysers (RFEAs) offers researchers, scientists, and engineers a versatile means to measure the ion energies and ion flux measurements [1, 2] at the substrate position, thereby providing deep insight into what happens at the wafer surfaces. RFEAs measure the uniformity of ion energies and ion flux hitting a surface, negative ions, and bias voltage at multiple locations inside a plasma chamber using an array of integrated sensors. A novel RFEA, that combines energy retarding grids with an integrated quartz crystal microbalance (QCM) allows measurements of the ion energy and flux properties as well as the ion-neutral ratio and deposition rate. The ion-neutral ratio is a critical control knob for optimizing film properties. A brief theory of operation will be described.

Measurements reported emphasize how the ion energy distribution of the ions impinging on the wafer can be adjusted with a broad range of plasma processing conditions. The data from various Oxford Instruments tools such as FlexAL, AtomFab, PlasmaPro, PlasmaLab will be presented [3, 4]. Some other major contributions to be showcased in this work include the evidence for low-energy ions influencing plasma-assisted ALD of SiO[5], adjustment of the Argon ion energy in controlling an ALE process [6] and the influence of ions and photons during ALD of metal oxides [7] etc., highlighting a few of the many possibilities that exist to gain more control over ALD/ALE processes.


[1] Impedans Ltd, Dublin, Ireland []

[2] S. Sharma et al., Ph.D. Thesis, Dublin City University (2016)

[3] J. Buiter, Master’s Thesis, Eindhoven University of Technology (2018)

[4] H. C. M. Knoops et al., J. Vac. Sci. Technol. A 39, 062403 (2021)

[5] K. Arts et al., Appl. Phys. Lett. 117, 031602 (2020)

[6] S. Dallorto, Ph.D. Thesis, Ilmenau University of Technology (2019)

[7] H. B. Profijt et al., ECS Trans.33 61 (2010)


ALD/ALE Processes

Atomic layer deposition (ALD) is a type of chemical vapor deposition (CVD). With the help of ALD improved control of film deposition can be achieved by splitting the deposition process into half-reactions.

Impedans Ion Energy Analysers provide critical insights into ALD/ALE processes – we have summarised the latest research papers that have used the Semion and Quantum RFEAs to study ALD/ALE plasmas in our newest application roundup.

Semion ALD/ALE Roundup

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