Friday, 22 December 2017

Season's greetings from Aalto University

Greetings were sent to all VPHA contributors (76) and prospective contributors (53). More people are still welcome to join VPHA.

Dear VPHA contributors and prospective contributors,

With this Aalto University electronic card, I wish you all happy holiday season and a prosperous 2018.

I have been slower in communicating in the last months about VPHA progress than I thought - this is because of the many duties and things to learn as a new professor and a group leader. I am still aiming for a final review article to be made from within VPHA. For this, some reading is probably still needed, updating information on the theses & conferences, sorting out data to create final tables. Also, we should discuss and decide how to archive the ALD-history-evolving-file after VPHA has ended. Expect more communication on this in the first months of 2018.

Best regards,
Riikka Puurunen, VPHA coordinator

Aalto University, professor, Catalysis Science and Technology

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

Tuesday, 15 August 2017

Story of Atomic Layer Deposition by Sven Lindfors, from Picosun newsletter December 2008

”I borrowed a bottle of hydrogen sulfide and, suddenly, there was a glowing golden growth covering the glass tube. We´d cracked it: this was the theory of advanced Atomic Layer Epitaxy taking physical form in front of my eyes.” 

"Story of Atomic Layer Deposition by Sven Lindfors, Chief Technology Officer and a Member of the Board of Directors of Picosun," initially published in the Picosun newsletter December 2008. The Picosun newsletter is no longer online and the story is republished in the ALD History Blog with the kind permission by Picosun Oy. Earlier related posts were "Sven Lindfors (1945-2017) in memoriam" and "Remembering Sven Lindfors - Svenin muistolle, by Tuomo Suntola". 

Screen capture from Picosun News, December 2008. With permission by Picosun. 

“We had numerous unsuccessful test runs behind us. Dr Tuomo Suntola knew that in order to proceed, we needed to advance from using pure chemical elements to an exchange reaction based on carrier gases and sulphides,” says Sven Lindfors, at the time working as a key technician for Dr Suntola’s team.

Saturday, 15 July 2017

Awards granted in relation with ALD - help to complete the list?

As mentioned in an earlier post, I am in the process of writing a Millennium Technology Prize nomination document for ALD and Tuomo Suntola. Supporting letters for the nomination are welcome from all over the world. At the time of writing this text, I have received five such letters. I hope that altogether we can collect  20-30 supporting letters - everyone's contribution is welcome.

About the nomination. It came to my mind that it might be worth listing to the nomination document the awards that have been granted worldwide to ALD so far. Below is my current list and some questions related to two possible additions.

Do you have another award in mind that someone has received anywhere in the world, from some recognized organization, which could be added to the list? If you have suggestions (need to be backed up by a document available in the internet), please leave a comment or contact me at

Awards so far which I am aware of - probably an incomplete list:

The two award where I am thinking if they can go to the list are the following. Opinions welcome.

Friday, 7 July 2017

Prof Steven George receives major AVS award for ALD

Professor Steven George from University of Colorado Boulder receives the John A. Thornton memorial award and lecture 2017 by AVS for "for seminal contributions to understanding, development and applications of atomic layer deposition". More on the award:

Steven George is one of those people who have dedicated a major part of their career for developing ALD. In addition to having led a world-leading university research group on ALD for about two decades, he is also a co-founder of ALD Nanosolutions (ALD History Blog posts here) and has authored for example the world's most cited review article on ALD in Chemical Reviews, 2010 (mentioned also in the ALD History Blog). In 2013, Steven George received the ALD Innovation award at the international AVS ALD conference (more on the 2016 award here).

Steven George will deliver the John A Thornton memorial lecture entitled " Atomic Layer Deposition: Highlights from the Last 25 Years" at the AVS 64 meeting on October 31, 2017. More details available via --> Program/Scheduler.

Congratulations to Prof. George!

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

Thursday, 22 June 2017

Remembering Sven Lindfors - Svenin muistolle, by Tuomo Suntola

This post continues upon a previous post, Sven Lindfors (1945-2017) in memoriam, by sharing the words of Tuomo Suntola at the funeral of Sven Lindfors on June 2, 2017. The words (in Finnish) are published with permission by Tuomo Suntola.

Sven Lindforsille 2.6.2017

- Osanottoni Svenin omaisille ja läheisille

Sunday, 4 June 2017

VPHA status update 4.6.2017 - Millennium Prize, Lindfors, HERALD Riga, VPHA's future

The status update copied below was sent to 76 current and 47 prospective VPHA contributors. 

From: Puurunen Riikka
Sent: 04 June 2017 09:10
Subject: VPHA status update June 2017 - Millennium Prize support, Lindfors in memoriam, HERALD Riga, future of VPHA

Dear current and prospective VPHA contributors,

This is the second update of the Virtual Project on the History of ALD (VPHA) in year 2017. The previous VPHA status update was set on March 22, 2017, link here.

This update shares information on the following topics:

  1. Millennium Technology Prize 2018 nomination - supporting letters welcome
  2. Mr. Sven Lindfors in memoriam
  3. Other posts
  4. Future activities in VPHA

Thursday, 25 May 2017

Where were you when I asked that question?

This post continues on an earlier post describing the ALD history activities before VPHA.

Triggered by events in the NetherlandsFinland and latest Latvia and the way that the history of ALD has been presented in them, I am finally writing a post which has been forming in the back of my mind for several months.

During the years, it has happened to me repeatedly that people start telling me their exact location "when you asked that question". They always refer to the ALD 2004 conference, "A joint American Vacuum Society ALD and Baltic ALD conference Celebrating 30 years of ALD", Helsinki, Finland, August 16-18, 2014. The conference pages were until quite recently still available at the address; now they seem to have disappeared. It should still be possible to obtain the abstract book here.

As the title says, the conference was celebrating thirty years from the invention of ALD in Finland in 2004. Dr. Tuomo Suntola was deservedly one of the invited speakers. His presentation is still available through his webpage, a link can be found also in the VPHA list of ALD history publications.

When the conference preparations started, I was a postdoctoral fellow at IMEC, Belgium. I of course wanted to participate in the conference, now that this big international event would arrive in Finland. I submitted several abstracts of my works (and got one talk + posters).

At IMEC, I had started to look into the history of ALD, as described in detail earlier here. I was well aware that ALD has not only been invented in Finland but also in USSR, and that the USSR work pre-dates that made in Finland. Seeing the title of the conference, "Celebrating 30 years of ALD", I was not quite sure what to think of it. My feeling was that I cannot be the only one who knows that this title is not correct. Don't they know, or don't they want to know?

Supporting Letters for Millennium Technology Prize 2018 nomination

updated 21.7.2017
Supporting Letters are sought for the Millennium Technology Prize 2018 nomination for ALD and Tuomo Suntola, especially to help describe the societal impact of ALD.

Since the day I promised to nominate atomic layer deposition and Tuomo Suntola for Millennium Technology Prize 2018, I have received positive feedback from many people and organizations, as well as questions on how one can support the nomination. Can Supporting Letters be prepared by individual persons or organizations? How does one prepare a Supporting Letter?

I try to answer all questions in this ALD History Blog post.

Scheme showing how a Supporting Letter could look like. 

HERALD COST MP1402 event in Riika (Riga), Latvia

On Monday May 22nd, I visited Riika (Riga), Latvia, giving an invited talk at an event called "ALD nanotechnology: advances, prospects and applications" organized within the framework of the HERALD COST action MP1402 ( The programme of the event, as provided by the organizers in advance, is copied at the end of this post.  

My presentation was entitled "On the history and future of ALD: VPHA, conformality analysis, mechanisms". The presentation explained the Virtual Project on the History of ALD (more volunteers are still welcome); introduced the PillarHall ALD conformality test structures developed at VTT (with a modelling example, too!) where we welcome more proof-of-concept partners; and pointed out the existing different views and a need to understand better the "model ALD process" trimethylaluminium-water. The presentation was dedicated to the memory of Mr. Sven Lindfors (1945-2017). At the end, I called for support letters to nominate Suntola and ALD for the Millennium Technology Prize 2018 (more to come on this in another post later). 

The presentation slides can be viewed in SlideShare. Additionally, Aalto University uses a tool called Panopto, with I tried, and with which I very easily could record my talk for later reference. A tool to be used in the future, too! The Panopto record can be viewed here.     

Some photos related to the event/this post below.

Sunday, 14 May 2017

Sven Lindfors (1945-2017) in memoriam

Sven Lindfors, "Svenkka", pioneer of ALD, in memoriam

Sven Lindfors, "Svenkka", a core pioneer of an atomic layer deposition (ALD), born November 25, 1945, passed away April 15, 2017 in Espoo, Finland. An obituary written by Tuomo Suntola and coworkers was published in the main Finnish newspaper Helsingin Sanomat today.  

I had the honour to cross paths with Sven Lindfors several times during our careers, first as a young master's thesis worker at Microchemistry Ltd. (1998) and later (2004-) as a research scientist at VTT Technical Research Centre of Finland. At VTT in 2004, it was my pleasant task to take into use the ALD reactor that VTT had bought from Sven Lindfors's company Picosun. The reactor was the first of its kind and was installed in the Micronova clean room, where it is still used, along with newer reactors installed later. Back at that time, Picosun had two employees. Today, thirteen years later, Picosun personnel counts over forty and Picosun itself has become a global brand.

Sven Lindfors was a visionary, composed of sunshine and thunder. As I knew Svenkka, for him, no need related to ALD reactors ever passed unsolved.

Saturday, 8 April 2017

Millennium Prize 2018 nominations now open - DL July 31

If you would like to join me to nominate Suntola for the Millennium Technology Prize, please contact - instructions at the end of the post. 

The nomination period for 2018 Millennium Technology Prize, given by Technology Academy of Finland, has opened on April 3, 2017. The Call for nominations can be found here: Everyone can nominate candidates.

The nomination instructions, as copied from the page are:

  • The nomination should include a Nomination Letter with a concise description of the cited innovation and the underlying technology, an assessment of the present and future impact of the innovation, as well as identification of the role of each nominee in the innovation process.
  • A concise separate CV must be supplied for each nominee.
  • All nomination material must be presented in English.
  • Please note that self-nomination is not allowed.

The general principles of the Millennium Technology Prize, as copied from the page, are:
  • Awarded to groundbreaking technological innovations that enhance the quality of people’s lives in a sustainable manner.
  • The innovations have been applied in practice and are delivering extensive change now and in the future.
  • The innovations stimulate further cutting edge research and development in science and technology.
I think that atomic layer deposition (ALD) easily fulfills all the listed general principles.

Thursday, 23 March 2017

VPHA status update 22.3.2017

The status update below was sent to 76 VPHA contributors and 46 prospective contributors. To register to get the next updates, please email info@
Begin forwarded message:

From: Puurunen Riikka < >
Subject: VPHA status update 22.3.2017
Date: 22 March 2017 at 21:37:12 GMT+2
Cc: Puurunen Riikka < >, Sundqvist Jonas < >

Dear current and prospective VPHA contributors,

This is the first VPHA status update in year 2017. For VPHA, this year has started with significant visibility: the review article published in JVSTA was the most read of all articles published in JVSTA. The previous VPHA status update was published on December 19, 2016. This update discusses the following topics:

  1. ALD history review article(s) in JVSTA
  2. Boulder & NanoSolutions & particle ALD -related ALD History Blog post + Weimer's guest post
  3. About the earlier ALD history activities + about VPHA's future
  4. Recent VPHA-related Wikipedia updates
  5. New affiliation by Puurunen (professor, Aalto University)
  6. Other posts in ALD History Blog (Pessa; ethics; PillarHall)

Wednesday, 22 March 2017

OT: Communication to VPHA participants on conformality analysis survey

The VPHA off-topic (OT) communication below was sent to 76 VPHA co-authors and 47 prospective co-authors. 

From: Puurunen Riikka
Sent: 15. maaliskuuta 2017 19:05
To: Puurunen Riikka < >
Cc: Utriainen Mikko < >
Subject: Conformality analysis survey link to VPHA participants

Dear VPHA co-authors and prospective co-authors,

This email is not related to VPHA but to lateral high-aspect-ratio test structures created to analyse the conformality of films made by ALD and other methods. I hope that you do not mind receiving this “off-topic” message sent to all VPHA participants. 

Some of you know that I have been recently working on the topic of conformality analysis of ALD films. Currently, we continue to work on it at VTT in a project funded by Finnish Funding Agency for Innovation. The recipient list has many people knowledgeable of the subject.

Tuesday, 14 March 2017

Krause writes about Aalto University's new catalysis professor

Professor emerita Outi Krause has written a very nice description related my new affiliation as professor of Catalysis Science and Technology at Aalto University. The text was originally meant for and published in "Katse", the newsletter of the Finnish Catalysis Society. With the permission of prof. em. Krause and the chairman of Finnish Catalysis Society, it is republished in this post in full (in Finnish).

--- originally published in Katse 1/2017 ---

Riikka Puurunen Aalto-yliopiston professoriksi

TkT Riikka Puurunen aloitti helmikuun alussa Aalto-yliopiston kemian tekniikan korkeakoulussa määräaikaisena teknillisen kemian professorina (associate professor) erityisalueenaan katalyysi.

Riikka Puurunen on TKK:n kasvatti. Hän aloitti opintonsa Kemian osastolla vuonna 1994, valmistui DI:ksi neljä ja puoli vuotta myöhemmin ja väitteli tekniikan tohtoriksi vuonna 2002. Jatko-opintoihin sisältyi myös vuoden tutkimusjakso K.U. Leuvenissä Belgiassa. Väitöksen jälkeen hän palasi Belgiaan postdoc-tutkijaksi IMEC-tutkimuskeskukseen. Riikka tuli takaisin Suomeen ja Otaniemeen v. 2004 VTT:lle tutkijaksi, josta hän siirtyi Aalto-yliopistoon. Hän jatkaa myös VTT:n osa-aikaisena vanhempana tutkijana tämä vuoden heinäkuun loppuun asti.

Monday, 13 March 2017

On the mammoth table - JAP 2005, JAP 2013 - next step VPHA?

The "mammoth table" of two-reactant ALD processes that many ALD researchers will have seen, was created for Puurunen's JAP 2005 review (open access here), and updated for the Miikkulainen et al. JAP 2013 review (open access here).

An idea has come up that it might be possible to update the table again within the Virtual Project on the History of ALD (VPHA). No promises yet---just an idea.

Screen capture of the first rows of the updated "mammoth table" spanning over 17 pages. Reprinted from V. Miikkulainen, M. Leskelä, M. Ritala, R. L. Puurunen, J. Appl. Phys. 113 (2013) 021301,, with the permission of AIP Publishing.

With the view of possibly updating the mammoth table, this post describes how the mammoth table was originally created and how it has been once updated. Whether or not an update will be made within VPHA, the background information shared here should be useful regarding an update that eventually at some point in some form most likely will be made. A previous post on the unique article codes used in VPHA is related to this post and the mammoth table: the unique coding was already started for the JAP 2005 review and re-used in the Miikkulainen et al. JAP 2013 review as well as in VPHA's ALD-history-evolving-file. If/when an update to the mammoth table will be made within VPHA, the unique article codes will be used again.

ALD surface chemistry review and the mammoth table - Puurunen, JAP 2005

The mammoth table aims to summarize all two-reactant ALD processes developed by a given timeline. The table was first created for the JAP 2005 review.

When writing the JAP 2005 review, I had a vision to try to write the kind of review article which I hoped would have been available when I started with ALD in 1998.

Guest post by Weimer: Early History of Particle ALD at the University of Colorado

Please find below the first guest post ever written for the ALD History Blog: Prof. Alan Weimer from the University of Colorado continues on the topic of a previous related post, sheading light to the early particle ALD developments at the University of Colorado and ALD NanoSolutions.   

--- guest post begins ---

Early History of Particle ALD at the University of Colorado

In 1997, Steve George and I started investigating the ALD on particles – Steve investigated the surface chemistry through in-situ FTIR and I investigated the processing to coat large volumes of fine particles using a fluidized bed reactor.   At that time, Steve was an ALD chemistry expert and I was expert in the synthesis and functionalization of fine particles, having worked in the area for nearly 20 years.  Much of my background was fluidized processing.  Very intense research that year indicated that we could use ALD to coat large volumes of primary particles identically without “gluing them” to neighboring particles.   HRTEM was key as well as surface area, particle size distribution, FTIR, and XPS measurements; and of course agitated particles.   I was quite surprised that individual primary particles could be coated as I knew that CVD inherently deposited nanoparticles formed in the gas phase, hence, forming agglomerated particles.

Monday, 6 March 2017

Copy of earlier communication to earlier ALD history review authors

A few days ago, copies of two emails were published in the ALD History Blog, which have been recently sent to the authors of the 2013 ALD history review to update them regarding the latest progress in VPHA. That the post has been re-tweeted in Twitter tells that the material has been of interest to someone. Link to post:

For completeness of info, in this post, an email is published from October 2013, where the authors of the then-new 2013 ALD history review were originally informed of and invited to participate in the then-recently started Virtual Project on the History of ALD.  

From: Puurunen Riikka
Sent: 8. lokakuuta 2013 10:31
To: <10 authors> 
Cc: Puurunen Riikka; Aziz Abdulagatov; Jonas Sundqvist; ALD Pulse
Subject: Virtual project on the history of ALD: introduction and invitation to participate

Dear authors of the recent ALD review, JVSTA 31 (2013) 050818, 

Virtual project on the history of ALD: Introduction and invitation to participate.

Did you know that the first publication of TiO2 thin films from TiCl4 and H2O by ALD on planar silicon substrates dates from year 1970? That Prof. Aleskovskii envisioned ALD as a "route to further miniaturization of microelectronic devices and to molecular electronics" in 1974? That a research group in St Petersburg has been active on ALD all the time since 1960's? These and many other things have already surfaced during the "virtual project on the history of ALD", an open worldwide collaborative effort to clarify the early history of ALD. Your participation in the “virtual project” would be very welcome and your expertise in the field of ALD highly useful for putting the new knowledge properly into place in today's perspective.

Saturday, 4 March 2017

New page: collection of ethical guidelines

New page created in ALD History Blog to collect together ethical guidelines from various sources related to the making and publishing of scientific research.


Contents as of March 4, 2017:
The goal is that the list will evolve with time to a more covering list. If you have suggestion of links to add, please let me know.

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

Tuesday, 28 February 2017

Copies of communications to earlier ALD history review authors

Copies below of recent emails to authors of the JVSTA 2013 ALD history review informing of the progress of the Virtual Project on the History of ALD.

-------- Alkuperäinen viesti --------
Aihe: RE: Article on the history of ALD: recommended reading list of early publications
Lähettäjä: Puurunen Riikka
Vastaanottaja: <10 authors>
Kopio: info@

Dear authors of JVSTA 31 (2013) 050818,,

I have written a blog post to describe the ALD history activities preceding the Virtual Project on the History of ALD. Maybe you can find it interesting. Your JVSTA 2013 review is briefly mentioned, under section “2013, the AVS ALD history article and VPHA”.

Saturday, 25 February 2017

On the "earlier ALD history activities" mentioned in the JVSTA focused ALD history review

As stated in the focused ALD history review recently published in the Journal of Vacuum Science and Technology A, the Virtual Project on the History of ALD (VPHA) "in essence, continues the earlier ALD history activities of one of the current authors, whose results were published in a review article in 2005."

In this post, I wish to tell more of the background of the earlier ALD history activities mentioned: how they started and what they were. The earlier history activities are related to my own doctoral thesis (2002) and the postdoctoral time after that.

Screen capture,  R. L. Puurunen's doctoral thesis at the Aalto University library server, access through

Microchemistry, Neste and Helsinki University of Technology - doctoral thesis

I made my Master's thesis in 1998 at Microchemistry, Espoo, Finland (nowadays part of ASM International), and continued for doctorate in 1999-2002 partly Neste and partly Helsinki University of Technology (HUT). Generalizing, the subject of my research was the surface modification of porous particles by atomic layer deposition for catalyst applications.