The homogenized beam of an excimer KrF laser has been used to form rectangular millimeter-scale holes of vertical walls in the ∼1 μm thick silicon-oxynitride (SiON) thin film deposited on Si 〈 111 〉 wafer. The regular rectangular craters in SiON layer have the flat bottom surface reaching the SiON/Si interface. At the same time horizontal thermal gradient causes the formation of the nanoscale Marangoni convection structures at the SiON/Si interface. The inhomogeneous pattern of the roll structures can be divided into domains of regular, irregular, and chaotic organizations. The roll diameter is about 200 nm while their average wavelength, , is, ∼2 μm, i.e., about ten times larger than the laser wavelength, and decreases with increasing number of pulses. Numerical simulation of the Marangoni domain roll structures based on the simple Swift-Hohenberg equation has reproduced all observed types of the roll organization, including those that show the evolution of dislocations from the Eckhause instability.
ASJC Scopus subject areas
- Physics and Astronomy(all)