Atomic layer deposition, ALD technology, was invented in the 1970s, and was initially used only to manufacture thin film electroluminescent displays. In the 1990s, microelectronics needed new kinds of materials, thin films and 3D structures, and the semiconductor industry adopted the ALD method. The new applications required expertise in chemistry which the University of Helsinki had.
Markku Leskelä was originally interested in luminescent materials, and his doctoral dissertation at the Helsinki University of Technology’s Faculty of Chemistry focused on luminescence. Since 1990, Leskelä has served as professor of inorganic chemistry at the University of Helsinki.
Smaller devices, atomic coatings
Manufacturing metal thin films through the ALD method is challenging. It is particularly difficult to make volatile noble metal compounds that tolerate the temperatures required in the process without decomposing into their metal form. Now a thermal ALD process has also been developed for gold. This is just one example of recent ALD research at the University of Helsinki.
– We are constantly searching for new ALD precursors and developing new processes, explains Professor Leskelä.
Researchers are currently working on new energy technology materials to be used in lithium batteries and solar cells. As ALD conforms to the shape of the surface, it can also be used on three-dimensional objects, such as energy technology equipment. Basic chemistry is used to develop the new processes.
Partnering with industry
– Still in the 1970s, the universities’ cooperation with the private sector was highly regulated, and the Ministry of Education wanted to restrict it further. Special permission was needed as soon as a contract exceeded 5,000 Finnish marks in value, reminisces Leskelä.
After Tekes was established in 1984, times began to change, and funding became available for joint projects between universities and industry.
The world’s semiconductor production is centralised in Asia and the United States, and is controlled by major corporations. But Finland as well has companies that manufacture ALD equipment (Beneq Oy, Picosun Oy), in addition to the R&D unit of the major Dutch ALD company, ASM Microchemistry Ltd. The University of Helsinki is involved in close cooperation with the Finnish branch of the company, ASM Microchemistry Oy, which has been based in the Chemicum building since 2004. ASM funds doctoral dissertations at the University of Helsinki which benefit the company. This industrial cooperation has helped the University to also conclude direct contracts with such giants in the semiconductor field as IBM, Intel and Samsung.
Honorary doctor at the University of Tartu
Markku Leskelä is a highly cited researcher and a leading figure in chemistry, a chair and member of several organisations in the field and a member of the Board of the University of Helsinki.
Of his many awards, Leskelä remembers the most recent ones with particular fondness. One of the examples of this is when he received the title of honorary doctor at the University of Tartu in a solemn ceremony held in December 2016.
But the most important recognition of Leskelä’s career was that from his colleagues and partners.
– I felt like an Oscar winner, when I suddenly had to give a thank you speech in front of the audience, describes Leskelä of the ALD award ceremony in Dresden in 2012.