One of the most exciting presentations I saw in last year was given by Rajesh Krishnamurthy, a senior technology analyst of TechInsights. He was invited at the 19^th International Conference on Atomic Layer Deposition in Bellevue WA, which also featured the 6^th International Atomic Layer Etching Workshop. During this ALD/ALE 2019 meeting (which I covered in blog posts here and here), he presented about “ALD and ALE process in commercially available leading-edge logic and memory devices”. He discussed the application of ALD and ALE processes in logic, DRAM and 3D NAND devices. He started with the well-known introduction of ALD by Intel for preparing high-k metal gate (HKMG) stacks in logic (since the 45 nm node) but he showed that ALD has nowadays many more applications in the leading-edge devices produced by Intel, TSMC and Samsung. As shown in the figure below, the 10 nm devices of Intel (see also this interesting article) are supposed to involve even as much as 70 (!) ALD steps when being manufactured. He elaborated about how these 3 companies use ALD for preparing HKMG stacks, for patterning of fins and making cuts, for depositing caps and etch stop layers, and for preparing liners for interconnect metals.

Rajesh also reported on the use of ALE in the manufacturing of the leading-edge devices as you can see in the same figure. This part leaves me somewhat puzzled as it indicates that ALE processes were already used in production since 2011. On the other hand, Lam Research announced that it introduced dielectric ALE capability for advanced logic in a press release only in 2016. In this press release it is suggested that it was the first process of (plasma-enhanced) ALE in high-volume manufacturing of logic devices in industry, the driving application being the SiO₂ etch for self-aligned contacts (SACs). In his presentation, Rajesh also mentioned several other applications of ALE but I think his interpretation of ALE might be somewhat wider than the common one in the atomic scale processing community. He talks about layer-by-layer etching which doesn’t necessarily have to be ALE. Moreover, I can imagine that it is somewhat harder to identify ALE process steps when reverse engineering a device. For ALD this should definitely be easier. For the preparation of extremely conformal and ultrathin films – certainly of some specific materials – there are hardly any alternatives.

Well, that was about the presentation of Rajesh Krishnamurthy at ALD/ALE 2019 conference. If you got interested, I very much recommend looking up his presentation in the AVS Technical Library. Here you find a screened version of his slides, no recorded audio is available. 

Now about ALD/ALE 2020, the main topic and title of this blog post! This year, the 20^th International Conference on Atomic Layer Deposition featuring the 7^th International Atomic Layer Etching Workshop was scheduled to take place to take place in Ghent, Belgium from June 28 to July 1. It was Europe’s turn as the conference schedule has so far been organized according an “ABAC-cycle”: U.S. – Asia – U.S. – Europe etc. The ALD chairs are Christophe Detavernier (Ghent Univ.), Jolien Dendooven (Ghent Univ.) and Paul Poodt (Holst Centre & Eindhoven Univ. of Technology) whereas the ALE chairs are Harm Knoops (Oxford Instruments & Eindhoven Univ. of Technology), Jean-Francois de Marneffe (IMEC) and me. All preparations went very smoothly, but then we had COVID-19….

As all other conferences since March this year, the physical version of the ALD/ALE 2020 conference had to be cancelled. Luckily enough the very professional AVS staff – in particular Della Miller and Yvonne Towse – quickly came up with a plan to hold a virtual ALD/ALE 2020 conference instead. This conference will kick off later today (June 29) and it will consist of live sessions (both for the technical program as for the tutorials) and on-demand presentations. The live sessions of the technical program will take place from Monday to Wednesday and will start at 10:00 EDT (Eastern Daylight Time)/16:00 CEST (Central Europe Summer Time) and take approximately 2.5 hours. There are no parallel sessions, so some highlights of the original program were selected for these live sessions. The tutorial presentations will take place on Tuesday and Wednesday and they will start at 13:00 EDT /19:00 CEST. All other presentations (oral and poster) will be made available on demand, at least if the presenters that originally submitted their abstracts opted for this. Also the talks presented during the live sessions and the tutorials will be made available for watching back. If you haven’t registered yourself yet, you can still do so here. Note that today’s live session (Monday program) is free of charge.

Let me also provide some interesting numbers. First of all, the number of abstracts submitted to this conference were an all-time high for the ALD/ALE conferences so far: 486 abstracts were submitted  (note that not all the originally accepted abstracts will be presented now the conference has gone virtual). Currently the total number of presentations is 259. The number of live presentations is 22 (including tutorials) and the number of invited presentations on-demand is 18. Furthermore, there are 130 contributed presentations on-demand and 88 posters. The registration is still open but at the moment 745 attendants have registered for the live sessions. The number of people that signed up for the tutorials is 338. These numbers are for both ALD and ALE. The ALE part is about 10% of the ALD part. Nearly all invited presentations of the ALE workshop will be available on demand.

Obviously, it is very unfortunate to cancel a conference but for many of us, postponing a contributed or invited presentation for a year is not a catastrophe. This is however different for students as they typically have only limited occasions to attend a conference of this scale. It really gets bad for students selected as finalists for Best Paper Awards. They might miss the only chance they had for competing. Therefore, as chairs, we decided to devote additional time for these finalists in the program of the virtual ALD/ALE 2020 conference. Given the difference in number of abstracts submitted for the ALD conference and the ALE workshop, much more time slots were made available for ALD presentations than for ALE. Hence, we were able to schedule a presentation for all 4 ALD Best Paper Award Finalists during the live session. This live session will take place on Tuesday and the winner will be chosen by the jury members afterwards. Personally, I’m very happy that one of the students that I co-advise has been selected as a finalist: Jeff Schulpen of the Eindhoven University of Technology (advisors: Ageeth Bol and me) will present his work entitled: Mixing It Up: Tuning Atomic Ordering in 2-D Mo_1-xW_xS₂ Alloys by ALD.

For the ALE Best Paper Award Finalists, we had not enough time slots available during the live session. Therefore, we decided to have a separate virtual pre-conference competition for the 5 ALE Best Paper Award Finalists. After seeing all students presenting their work, the jury members decided on the winner who would be given the opportunity to present his work during the live session on Wednesday (10:45 EDT/16:45 CEST). Also, here one of the students I’m co-advising was a finalist and hence I was not part of the jury. I want to stress that here as I’m very happy to announce here that Nick Chittock of the Eindhoven University of Technology (advisors: Adrie Mackus and me) was selected as the winner of the ALE 2020 Best Student Paper Award for his presentation entitled: Isotropic Plasma ALE of Al₂O₃ using SF₆ Plasma and TMA. See the announcement slide below.

Talking about announcements, during the live session I will also have the honor to announce the location of next years’ ALD conference and ALE workshop as well as the 2021 ALD and ALE chairs. See below the slide that I will present later today below. Please check out next year’s conference website here. I very much hope that we have defeated the coronavirus 2019 disease by then and that we can safely meet in person again!

To end this blog post, I would like to give an overview of all the contributions from the Eindhoven University of Technology to be presented at the ALD/ALE 2020 virtual conference. Please see the list below, hopefully you will enjoy!

Tuesday, June 30	10:45 EDT/ 16:45 CEST	LI2-TuM10 ALD 2020 Best Student Paper Finalist Talk: Mixing It Up: Tuning Atomic Ordering in 2-D Mo1-xWxS2 Alloys by ALD; Jeff Schulpen‚ Erwin Kessels‚ Vincent Vandalon‚ Ageeth Bol (Eindhoven University of Technology‚ Netherlands)
Wednesday, July 1	10:45 EDT/ 16:45 CEST	LI3-WeM10 ALE 2020 Best Student Paper Award Talk: Isotropic Plasma ALE of Al2O3 using SF6 Plasma and TMA; Nicholas Chittock‚ Martijn Vos‚ Adrie Mackus (Eindhoven University of Technology‚ Netherlands); Harm C.M. Knoops (Oxford Instruments Plasma Technology‚ Netherlands); Erwin Kessels (Eindhoven University of Technology‚ Netherlands)
On Demand		AF2-TuM07 Role of Ions in Film Conformality and Quality during Plasma-Assisted ALD of SiO2 and TiO2; Karsten Arts‚ Sanne Deijkers (Eindhoven University of Technology‚ Netherlands); Mikko Utrianen (VTT Technical Research Centre of Finland); Riikka Puurunen (Aalto University‚ Finland); Erwin Kessels‚ Harm C.M. Knoops (Eindhoven University of Technology‚ Netherlands)
On Demand (Invited)		NS1-WeA01Atomistic Simulation of ALD of 2D Transition-Metal Dichalcogenides; Mahdi Shirazi‚ Erwin Kessels‚ Ageeth Bol (Eindhoven University of Technology‚ Netherlands)
On Demand		AF2-MoA02 Ion Energy Distribution and Fluxes for a Newly-Designed Remote Plasma Source for ALD for GaN Devices; Harm C.M. Knoops (Oxford Instruments Plasma Technology‚ Netherlands); Karsten Arts‚ Jan Buiter‚ Luca Matteo Martini (Eindhoven University of Technology‚ Netherlands); Tania Hemakumara (Oxford Instruments Plasma Technology‚ Netherlands); Michael Powell (Oxford Instruments Plasma Technology‚ UK); Agnieszka Kurek‚ Yi Shu (Oxford Instruments Plasma Technology‚ Netherlands); Erwin Kessels (Eindhoven University of Technology‚ Netherlands); Chris Hodson‚ Aileen O’Mahony (Oxford Instruments Plasma Technology‚ Netherlands)
On Demand		AS-WeA01 Area-Selective Atomic Layer Deposition of 2D WS2 Nanolayers using Inhibitor Molecules; Shashank Balasubramanyam‚ Marc Merkx (Eindhoven University of Technology‚ Netherlands); Marcel Verheijen (Eurofins Materials Science Netherlands B.V.‚ Netherlands); Erwin Kessels‚ Adrie Mackus‚ Ageeth Bol (Eindhoven University of Technology‚ Netherlands)
On Demand		ALE1-TuM06 Precise Ion Energy Control with Tailored Waveform Biasing for Atomic Layer Etching; Tahsin Faraz‚ Yuri Verstappen‚ Marcel Verheijen (Eindhoven University of Technology‚ Netherlands); Javier Lopez‚ Erik Heijdra‚ Wouter van Gennip (Prodrive Technologies B.V.‚ Netherlands); Erwin Kessels‚ Adrie Mackus (Eindhoven University of Technology‚ Netherlands)
On Demand		AF2-MoA03 Plasma-Enhanced Atomic Layer Deposition of Cobalt and Cobalt Nitride: What Controls the Incorporation of Nitrogen?; Gerben van Straaten‚ Rick Deckers‚ Martijn Vos‚ Erwin Kessels‚ Adriana Creatore (Eindhoven University of Technology‚ Netherlands)