ALD research takes a leap forward: now we can study what happens at the surface level in ALD

29.6.2021
New research equipment acquired by the ALD laboratory at the University of Helsinki is opening up new dimensions. The new instrument connects the ALD reactor to surface-analysis techniques via a vacuum.

The HelsinkiALD laboratory, headed by Professor Mikko Ritala, has been developing ALD (atomic layer deposition) for 30 years now. The technique is deployed within the semiconductor industry around the world.

"Though we already have good information on the properties of thin films, and their growth mechanisms have also been studied for long, we have not until now been able to properly study what kind of reaction intermediates form on surfaces. With the help of the new instrument, we can analyse samples in a vacuum, which avoids any reaction between the air and intermediates that have a thickness of only one molecular layer", says Mikko Ritala.

Installation delayed due to Covid-19 pandemic

The surface analysis instrument acquired by the ALD center Finland arrived from Poland in December 2020. Due to the pandemic, the transport crates waited to be unpacked in a corridor in Chemicum for the early part of the year. At the end of April 2021, the installers were allowed to enter the country, and after a couple of Covid tests they were finally given access to assemble the instrument. The Polish surface-analysis equipment was connected to an ALD reactor manufactured by Beneq in Espoo.

For twenty years already, Finnish ALD researchers have been dreaming about this kind of research equipment, of which there are only a few world-wide.

"This kind of instrument is not needed in manufacturing, but the industry is also interested in what it can teach us. Hopefully we will soon find out how thin films grow and what kind of interfaces they form downwards", Ritala says.

Extensive service to research

Surface intermediates can still not be monitored in real time, but rather, the sample has to be transferred. This process is carried out in one part of the equipment and the sample is analysed in another part.  Since samples can also be introduced into the equipment in other ways, it can serve a large group of users.

The Profi4 funding of the Academy of Finland enabled this 1.2-Million-Euro purchase, which will benefit also other users besides ALD research, such as catalyst researchers at the University of Helsinki.  The selection of ALD center Finland to the roadmap of national research infrastructures gives rise to interesting opportunities for further development of the equipment.