Monday, 31 December 2018

Molecular Layering in the 2018 Millennium Prize Nomination letter

In 2018, Dr. Tuomo Suntola received the Millennium Technology Prize (MTP) for his groundbreaking work on Atomic Layer Deposition (ALD). In addition to being a personal recognition to Suntola, the MTP 2018 was a great recognition to ALD as an enabler of many technologies and of the continuation of Moore’s law. The whole field has benefited.

In the Virtual Project on the History of ALD (VPHA), materials (publications, Wikipedia updates) have been created which supported the nomination. In summer 2017, it was a natural continuation of VPHA to write the MTP nomination letter for me in the name of my university.

ALD has been invented independently twice - under the name Atomic Layer Epitaxy by Tuomo Suntola in 1974, and under the name Molecular Layering by Valentin Aleskovskii and Stanislav Koltsov already in the 1960s (see, e.g., Wikipedia).

When writing the MTP nomination letter, in addition to describing Suntola’s groundbreaking work and the impact of ALD from all angles, I also - of course - I wanted to acknowledge the pioneering work of Aleskovskii and Koltsov, who both have already passed away.
It may be interesting for the VPHA participants to see the final wording, and I have decided to publish it in this blog post - please see below. The text reflects my understanding in July 2017 and it is still the same at the end of year 2018.

I welcome any discussion which may arise from the publishing of this text. Let’s do it in the VPHA way - in atmosphere of Openness, Respect, and Trust.

Thanking for 2018, wishing everyone a great 2019,
Riikka Puurunen
December 31, 2018, Espoo, Finland

*** text from MTP 2018 nomination letter begins ***

2  Independent discovery of “molecular layering”

The principles underpinning ALD have also been independently discovered in an academic university research group in the USSR in the 1960s (Puurunen2005, Malygin2015, Ahvenniemi2017). Professor Valentin B. Aleskovskii and his student Stanislav I. Koltsov named the technique “Molecular Layering” (ML) in 1965 (Ahvenniemi2017). There has since then been significant research activity on this topic in USSR and later in Russia.  These research activities remained unknown to the Finnish and international ALD research community, until the first international ALE conference was organized in Espoo, Finland, in 1990 (Puurunen2014), where the Russian scientist Victor Drozd participated, thereby creating the first personal connections between the ALE and ML branches of ALD activities.

Despite the connections generated in 1990, ML-ALD has for some reason remained rather poorly known within the international ALD community. The first real effort to describe the early ML-ALD works internationally was in the review article by Puurunen in 2005 (Puurunen2005). In 2013, “Virtual Project on the History of ALD” (VPHA) was launched, “carried out in atmosphere of openness, respect, and trust,” to clarify remaining open questions related to the history of ALD. In VPHA, coordinated by R. L. Puurunen, volunteer scientists from over 20 countries have together produced an overview of early ALD literature (up to 1986). A number of conference presentations and three journal articles have been produced within VPHA. The three VPHA-related journal articles serve as a fundament for this Millennium Prize nomination letter. The first article is an essay on the atomic layer epitaxy developments led by Suntola (Puurunen2014), written by R.L. Puurunen from Espoo, Finland.  The second article is a complementary essay on the molecular layering developments by Aleskovskii and Koltsov (Malygin2015), written by four professors from St. Petersburg, Russia. The third article is a review article written in international collaboration by 62 co-authors, reporting a “recommended reading list of early ALD publications” (Ahvenniemi2017). The “recommended reading list” (Ahvenniemi2017, Table 1) was created through voting by the VPHA participants, and it highlights the importance of the publications and patents by Suntola and co-workers in addition to pointing to the most important contributions of international research on ALD up to 1986. The review by Ahvenniemi et al. (Ahvenniemi2017) also describes how VPHA started and which were the ALD-history-related developments preceding it.

Both original USSR discoverers of ALD have passed away several years ago, Aleskovskii in 2006 and Koltsov in 2003 (Malygin2015), leaving Dr. Tuomo Suntola as the sole living inventor of ALD and thus avoiding the question of whether the ML discoverers also should be nominated for the prize.

While the ML-ALD branch of ALD would definitely deserve more attention in the international scientific literature than it has received so far, it is worth noting that today’s leading Russian researchers/professors clearly admit that the leadership of current-day ALD technology lies with the Suntola-developed branch of invention. In the recent essay, Malygin et al. state (Malygin2015, p. 223): “ … Russia started, and continues to purchase, ML/ALD technologies from foreign manufacturers. Today there is no doubt that non-Russian entities are the current leaders in both the science and industrial application of ML/ALD technologies.”    

(Ahvenniemi2017) E. Ahvenniemi et al. (in total 62 co-authors), “Review Article: Recommended reading list of early publications on atomic layer deposition—Outcome of the “Virtual Project on the History of ALD”, Journal of Vacuum Science and Technology, A 25 (2017) 010801 (13 pages). Open access.

(Malygin2015) A. A. Malygin, V. E. Drozd, A. A. Malkov, V. M. Smirnov, "From V. B. Aleskovskii’s "Framework" Hypothesis to the Method of Molecular Layering/Atomic Layer Deposition", Chemical Vapor Deposition 21 (2015) 216-240.

(Puurunen2005) R. L. Puurunen, "Surface chemistry of atomic layer deposition: A case study for the trimethylaluminum/water process", Journal of Applied Physics (Applied Physics Reviews) 97 (2005) 121301 (52 pages), Open access:

(Puurunen2014) R. L. Puurunen, "A short history of Atomic Layer Deposition: Tuomo Suntola's Atomic Layer Epitaxy", Chemical Vapor Deposition 20 (2014) 332-344, Open Access.

*** text from MTP 2018 nomination letter ends ***

Virtual Project on the History of ALD (VPHA) - in atmosphere of Openness, Respect, and Trust

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