1. Łukasiewicz Research Network─PORT Polish Center for Technology Development, Stabłowicka 147, Wrocław 54-066, Poland
2. Department of Semiconductor Materials Engineering, Wrocław University of Science and Technology, Wyspiańskiego 27, Wrocław 50-370, Poland
3. Institute of Experimental Physics, University of Wrocław, pl. M. Borna 9, Wrocław 50-204, Poland
4. Department of Nanometrology, Wrocław University of Science and Technology, Janiszewskiego 11/17, Wrocław 50-372, Poland