18 June | Dr Nick Chittock and Dr Emma Coleman

Atomic precision for the quantum era 

How ALD and ALE are enabling high-performance, manufacturable quantum devices through ultra-precise control of materials, interfaces, and fabrication processes

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With quantum technologies making the transition from laboratory demonstrations to scalable, manufacturable systems, the demands placed on materials and processes are intensifying. Achieving reliable qubit performance, ultra-low loss photonics, and repeatable device architectures all hinge on atomic-scale control of thin films, interfaces, and surfaces. Alongside more conventional and longstanding fabrication techniques, atomic layer deposition (ALD) and atomic layer etching (ALE) are becoming trusted processes for advancing quantum technologies. 

As the name suggests, ALD and ALE are essential for achieving atomic-scale process control. Both technologies play vital roles in engineering precise and uniform materials, often enabling material thickness control at the Ångstrom scale. ALD enables the growth of complex, ultra-thin films with exceptional thickness and stoichiometric control, while ALE allows the layer-by-layer removal of material, ensuring dimension and surface damage control. At Oxford Instruments these technologies are seamlessly integrated into our quantum solutions. Across superconducting, photonic, and colour centre quantum technologies, our systems address the needs of both quantum information processing and quantum sensing devices.

Figure 1: Oxford Instruments Plasma Technology's cleanroom team in state-of-the-art facility, Bristol, UK.

Our development plasma enhanced ALD (PEALD) platform, PlasmaPro ASP, and production PEALD platform, Atomfab, share design DNA, allowing processes developed in research environments to be transferred rapidly and reliably into manufacturing. PEALD combines the self-limiting nature of ALD with the additional tuneability and flexibility provided by a remote plasma source. PEALD has been demonstrated to enable lower impurity content, shorter cycle times, and enhanced tunability compared to thermal ALD. Both our PEALD systems share the same patented plasma source architecture and user interface, reducing risk during scale up. (To learn more about these complementary systems, check out the article from Semi Interface issue 3). For quantum technologies, device architectures and the materials in them are evolving rapidly, and it is therefore necessary to iterate multiple versions of devices with different film properties to stay ahead of the game. However, while chasing improved performance one eye must be kept on the eventual scalability of device and process solutions. Continuity between our two systems provides a practical pathway from early-stage innovation to manufacturable solutions.

Figure 2 & 3: (Left) PlasmaPro ASP our PEALD development platform designed for rapid process development. (Right) Atomfab (four in a cluster), built with the same plasma source as the ASP and targeting PEALD for production environments.

For ALE, our PlasmaPro 100 Cobra system offers Ångstrom-level etch control, providing smooth surfaces, high selectivity, and minimal plasma damage to surfaces and interfaces. One of the leading causes of loss across different modalities of quantum sensing and computing is etch induced damage, and ALE provides a route towards minimising this. Outside the quantum space, ALE is already being applied to enable low damage fabrication. For example, in complementary metal-oxide-semiconductor (CMOS), microLED and metal-insulator-semiconductor high-electron mobility transistor (MISHEMT) device fabrication, low damage ALE processes have been demonstrated to improve device performance. For quantum, ALE is largely untested territory, however literature reports indicate that it may provide similar benefits. The Cobra ALE system is compatible with wafers of up to 200 mm and can be equipped with a single wafer loadlock, cassette handler, or as part of a cluster.

Figure 4: Cobra ALE system attached to an automated cassette handler to enable high throughput processing for both ALE and ICP-RIE.

AVS ALD/ALE Conference

This summer, the AVS 26th International Conference on ALD, combined with the 13th International ALE Workshop, will be held in Florida, USA. Tampa will become the hub for ALD and ALE experts from around the world, bringing together researchers, engineers, and industry leaders to share the latest advances in these precision process technologies, where quantum is increasingly becoming part of the conversation. In fact, quantum has its own session - Quantum ALD Applications - moderated by our own Dr Arpita Saha.

Figure 5: Oxford Instruments Plasma Technology's team at the AVS International Conference, 2025.

Oxford Instruments will be there to exhibit our advanced ALD and ALE solutions, highlighting how the team of in-house engineers and researchers-in-residence are developing these technologies to address the challenges of scaling and performance for next-generation devices. Dr. Arpita Saha, Deposition Solutions Manager, and Dr. Harm Knoops, Atomic Scale Segment Expert, both sit on the ALD and ALE Steering Committees, respectively. In addition to moderating sessions, alongside other Oxford Instruments colleagues, they will present innovative research for advanced quantum and power electronics devices. Here is a quick look at this year’s topics… 

Superconducting Nitrides by Fast Remote Plasma ALD for Quantum Applications 

Dr Harm Knoops - Atomic Scale Segment  

High Rate, Tuneable Dielectric Nitrides by Plasma Atomic Layer Deposition Enabling Volume Manufacturing for GaN Device Integration 

Dr Arpita Saha - Deposition Solutions Manager  

Examining AlGaN Atomic Layer Etch per Cycle Uniformity and Repeatability by Cross-Referencing In-Situ Etch Depth Monitoring with Electrical Characterisation 

Dr Ben Jones - Applications Engineer  

Multi-Cycle Plasma Enhanced Atomic Layer Deposition of Superconducting Nitride Structures for Photonics and Quantum Computing Applications 

Dr Nick Chittock - Quantum Technologies Market Specialist  

Collaborator contributions   

Dr Adrie Mackus, Eindhoven University of Technology – Talk; Precise and narrow ion-energy distributions in plasma-enhanced ALD of nitrides using tailored-waveform biasing   

Ivy Chen, Caltech – Talk; Directional atomic layer etching of MgO-doped lithium niobate using Br-based plasma. Poster; Improving optical resonator quality factors in thin-film lithium niobate with atomic layer etching  

Ryan Walsh, University of Nevada, Reno -Talk; Atomic layer etch process for Nb and Ta using CF4/H2 plasma  

Dr Sebastian Mohr & Lucy Manukyan, Quantemol ltd. – Poster: Numerical and experimental investigations on tailored waveforms  

Semi Interface #6: Quantum Edition - coming soon!

We’ll be diving deeper into the technologies shaping the quantum future in our next edition, including more on how our atomic scale processing technologies are enabling next-generation quantum devices.

Explore previous editions here:

Explore Semi Interface Magazine

Peeters, S. A.; Nelissen, L. E. W. H. M.; Besprozvannyy, D.; Choudhary, N.; Lennon, C. T.; Verheijen, M. A.; Powell, M.; Bailey, L.; Hadfield, R. H.; (Erwin) Kessels, W. M. M.; Knoops, H. C. M. Superconducting Nb x Ti1− x N Prepared at High Deposition Rates with Plasma-Enhanced Atomic Layer Deposition and Substrate Biasing. AVS Quantum Science 2025, 7 (2). https://doi.org/10.1116/5.0254.... 

Shiravand, I.; Jamalzadeh, M.; Nguyen, M.; Nadeau, C.; Perez, M. M.; Hwang, S.; Tong, X.; Nykypanchuk, D.; LaHaye, M.; Shahrjerdi, D. Investigation of Kinetic Inductance and Microwave Loss in Thin-Film TaCxN1−x Superconducting Resonators. Appl Phys Lett 2025, 127 (19). https://doi.org/10.1063/5.0300.... 

de Leon, N. P.; Itoh, K. M.; Kim, D.; Mehta, K. K.; Northup, T. E.; Paik, H.; Palmer, B. S.; Samarth, N.; Sangtawesin, S.; Steuerman, D. W. Materials Challenges and Opportunities for Quantum Computing Hardware. Science (1979) 2021, 372 (6539). https://doi.org/10.1126/scienc.... 

Honda, M.; Katsunuma, T.; Tabata, M.; Tsuji, A.; Oishi, T.; Hisamatsu, T.; Ogawa, S.; Kihara, Y. Benefits of Atomic-Level Processing by Quasi-ALE and ALD Technique. J Phys D Appl Phys 2017, 50 (23), 234002. https://doi.org/10.1088/1361-6.... 

Liu, T.; Liu, Z.; Cao, H.; Nong, M.; Tang, X.; Jiang, Z.; Garcia, G. I. M.; Ren, K.; Li, X. Significant Improvement of Breakdown Voltage of Al0.86Ga0.14N Schottky Barrier Diodes by Atomic Layer Etching. Appl Phys Lett 2025, 126 (15). https://doi.org/10.1063/5.0251.... 

Liu, Z.; Cao, H.; Liu, T.; Lu, Y.; Tang, X.; Jiang, Z.; Xiao, N.; Li, X. Alleviate Sidewall Damage of InGaN Green Micro-LEDs by Atomic Layer Etching. Opt Lett 2025, 50 (11), 3756. https://doi.org/10.1364/OL.561.... 

Michaels, J. A.; Delegan, N.; Tsaturyan, Y.; Renzas, J. R.; Awschalom, D. D.; Eden, J. G.; Heremans, F. J. Bias-Pulsed Atomic Layer Etching of 4H-Silicon Carbide Producing Subangstrom Surface Roughness. Journal of Vacuum Science & Technology A 2023, 41 (3). https://doi.org/10.1116/6.0002.... 

 Hossain, A. A.; Murphy, S.; Catherall, D. S.; Ardizzi, A. J.; Minnich, A. J. Atomic Layer Etching of Niobium Nitride Using Sequential Exposures of O2 and H2/SF6 Plasmas. Journal of Vacuum Science & Technology A 2025, 43 (4). https://doi.org/10.1116/6.0004....​​