Celebrating the 50th anniversary of ALD at ALD/ALE 2024 in Helsinki! – Updates of the history of ALD in timelines and the animated version of the ALD periodic table

Next week, from August 4 to 7, the ALD/ALE 2024 conference will be held in Helsinki, Finland. This event marks the 24th International Conference on Atomic Layer Deposition and will also include the 11th International Atomic Layer Etching Workshop. This year’s conference is particularly special as we celebrate the 50th anniversary of ALD, commemorating 50 years since Tuomo Suntola and Jorma Antson filed their first patent on ALD. The fact that this milestone occurred in Finland is why the conference is being held in Helsinki once again, with Mikko Ritala and Markku Leskelä serving as ALD chairs. Dr. Tuomo Suntola will even deliver the opening remarks at the conference! As a community, we are eagerly looking forward to this momentous occasion, along with a robust program featuring plenary and invited speakers (Ivo Raaijmakers of ASM will present the ALD plenary lecture this year), as well as numerous high-quality contributed talks and posters. We can hardly wait for this festive event!

Five years ago, when ALD turned 45 years, I wrote also a blog post addressing some of the history of ALD and I also included a timeline of ALD. Furthermore, it contained an animated version of the ALD periodic table as can be found in the “famous” ALD database. That previous blog post can be found here. In this blog, I aim to provide a brief update, including the latest versions of the ALD timelines and the animated ALD periodic table.

Yet before doing so, I would also like to show an updated version of the list of previous ALE and AVS ALD-ALE conferences (note that the first ALE stands for “atomic layer epitaxy” and the second ALE for “atomic layer etching”). This list was originally published in an article about the history of ALD and especially also its relationship with the American Vacuum Society (AVS). This article was published in the Journal of Vacuum Science and Technology A in 2013 and 1st authored by Greg Parsons. Clearly, ALD/ALE 2024 is doing very well, both in terms of number of abstracts and in number of attendees!

Below is the updated version of the previous ALD timeline. As emphasized five years ago, this timeline is a simplified graphical representation of the history of ALD and does not capture all significant developments in the field. It is, in fact, a personal interpretation. However, I hope it will still be insightful for the community. This update includes only a small, yet important addition compared to the previous version, besides highlighting that ALD has now reached its 50th anniversary: notably, after many years of research, ALD is now used in the commercial production of Li-ion batteries. This has been confirmed by Arrelaine Dameron from Forge Nano, who will also be speaking at ALD/ALE 2024. The title of the presentation that she will give is “Development and Scale-up of ALD onto Synthetic Graphite Powder in a Continuous Vibrating Reactor for Battery Applications.” The commercial application of ALD in Li-ion battery production is also highlighted in the press release by Forge Nano earlier this week.

Talking about the commercial use of ALD, I thought it would be nice to illustrate its applications in high-volume manufacturing. To do so, I created a second version of the ALD timeline, shown below. This timeline was inspired by Jin-Seong Park from Hanyang University, with whom I collaborated on a joint publication (still to be published). Like the original, this timeline begins with the first patent in 1974 and mentions the first commercial application of ALD in inorganic thin film electroluminescent (TF-EL) displays. Although TF-EL displays and the production of magnetic heads did not reach high-volume manufacturing levels comparable to some other applications, they were significant milestones for ALD’s entry into manufacturing.

The use of ALD in DRAM, logic, and 3D NAND truly represents high-volume manufacturing, as these applications are integral to the smartphones, tablets, and laptops we use daily (and to read this blog post). Additionally, although ALD in self-aligned multiple patterning (SAxP) appears in DRAM and logic devices, it is worth highlighting this critical application of ALD in which the ALD materials are used sacrificially. I wrote a blog post about it several years ago, see here. I also want to emphasize ALD’s widespread use in solar cell production (see blog posts here and here) and its recent application in OLED display production (as announced by LG display at ALD/ALE 2020). Now the emerging role in Li-ion battery production has been added to the timeline too. Also note that I published a figure about (niche) applications of ALD  earlier in this blog post.

Finally, to wrap this blog post up, I would like to come back again to the 50th anniversary of ALD. Over the years, a very large set of materials has been prepared by ALD. This number is still growing, and it will further progress the method and its applications. The growing number of materials that have been prepared by ALD can be visualized using the ALD periodic table that is part of the online ALD database. See the animated version below. Feel free to share and use it.

Hope to see you in Helsinki next week!