The thermal stability of tungsten/silicon multilayered nanostructures

The influence of excimer laser processing on the thermal stability, especially on the surface roughness evolution of W1yxSixrSi multilayers?MLs.,isstudied.MLswiththecompositionsx s 0?WrSi.andx s 0.33,0.5and0.66wereevaporatedbye-beam evaporation and co-evaporation onto Si substrates. The samples were irradiated by XeCl laser pulses at fluences Fs0.075-0.6 J cmy2 and Ns1 or 100 pulses. Then, they were studied by atomic force microscopy, thus completing previous X-ray scattering analyses. It was found that for xG0.5 the clusters are formed at the MLs surface even in the as-deposited state. Sources of surface roughness are the laser melting itself, Si crystallization and shrinking of the volume connected with the formation of tungsten silicides.