Igor Korczagin (promotion date: 10 February 2005)

Poly(ferrocenylsilanes) mer in micro- and nano fabrication; materials chemistry and surface patterning for lithography and catalysis

Promotion Date: 10 February 2005

What was your thesis about?

The main goal of this thesis was to investigate materials that we could use in surface patterning and later apply them in lithography: polymeric materials we could use to circumvent the photolithography. The photolithography equipment is very expensive and it has got its limitations as well. So we investigated the concept of self assembly in polymeric materials. Basically I would call it a material research project. Still very fundamental.

Have you found the ideal material?

I think that has been found before, we are not actually looking for the optimum material for nano structures, but the ferro bit of the thesis title is the crux of the matter. If you consider plastics, polymers, the are organic compounds built of carbon and hydrogen (and perhaps a bit of oxygen and other substances, but carbon and hydrogen are the most important elements).

We chemically embedded iron in the polymer. When we introduced the iron we added some distinct functionality to the general properties of polymers.

Does the iron facilitate working in very small structures?

Yes, that is one of the uses you could make of this particular material. The iron and the silicon when oxidized you form an iron silicon oxide which is not volatile, as opposed to the carbon silicons that are. In fact you make a ceramic, which can be used on a nano scale. That is the first application. We also make use of the fact that the iron oxide can be etched much slower than the silicon oxide, resulting in contrasting etching rates. So we can use that property in making masks. And that is the second important result, but still only an example of what you could do by introducing the iron in your polymer. It is the tip of an iceberg. We can also position carbon nano tubes (nano tubes are created by means of a catalyst) exactly on the right spot of a silicon surface, which is again a step forward in nano technology. I fact you can let your imagination loose and think of numbers of other applications.

Was the iron never thought of?

Not in polymers. If you think of a polymer as a chain and have two different polymers, they will not mix. They separate quite visibly. If you introduce iron in the one polymer and not in the other, you create a contrast but the iron locks the polymers locally ordering the molecules in a nicely structured way. So now the principle of self assembly creates structures that otherwise will have to be made with nano lithography. You use the polymer to deliver iron into a specific shape, size and place on your surface. So for nano technology in general this is an important step. You get this structured ordering for bigger surfaces, it is cheap and you do not even have to make it in the clean room. The combination of the iron properties and polymer properties is the innovative bit. But we are not at the stage yet of industrial applications, we are optimizing the material science.

You have to have an open mind to discover the advantages of two substances that are usually researched separately. Mesa+ is the ideal environment for that because of its many disciplines within one organization. Our group was involved in the work of Poly Nano, resulting in interactions with other groups that were not necessarily dealing with the same materials. A good example is the group in Neuchatel working on nano tubes. We did our stuff and this put together results in a new application.

What did you like most about your research?

The fact that on the one hand I was able to synthesize the materials myself and on the other investigate their properties and use the facilities here to put them into practice. I was responsible for the entire chain. That is very rewarding. That at the same time was very demanding to, as a chemist you have to step into the clean room, learn the physics and to operate the machinery as well.

Was there a moment of despair?

There is always the risk that you choose the wrong strategy. You think your concept is right and you do not get the right results. Then you have to make a strategic decision: to continue or not to continue? The nightmare of every PHD student who has the liberty of pursuing his own ideas, which is the real challenge for every starting scientist. I tried a synthesis and eventually it did not work out. We spent one year and a half and failed. But in science you say a failure is also a result, but still I had nightmares, because we were on the quest of this magic material and could not get it, and time is not unlimited… I was lucky enough to find another way and got very nice results.

What is your background, and how come you speak Dutch is so extremely well?

I am from Poland, my mother is Polish and my father Russian. I was born in Leningrad (now St Petersburg). When I was six my parents moved to Poland. As for the language: I went to a course, but missed so much of it that it remained challenging. On the whole I have no problem with languages.

What are you going to do next?

At the moment I started work at the University of Gdansk in Poland. I work with a group that works with renewable energy sources.

So this has nothing to do with your PHD research?

You never know. The most interesting discoveries are always on the interface of different areas.