Gavryliuk O. Laser-inducted nanostructuring of non-stoichiometric films SіOx

The thesis is devoted to investigation of spreading temperature profiles and impact of a temperature on forming silicon nano-particles in non-stoichiometric films SіOx after laser annealing. Using parabolic equation of heat transfer, mathematical modelling temperature profiles formation is realized in a non-stoichiometric film SіOx after laser annealing. It is shown that the temperature 1800 К on the SіOx surface is sufficient for division of the film substance into silicon dioxide and its nano-particles. IR - investigations confirmed the division. Studies of creating temperature profiles in process of annealing by two laser beams show that silicon nano-particles are formed precisely on the positions of peak intensities of laser radiation. When many-pulse annealing takes place, a low energy density can guarantee the film SіOx annealing without damages. Analysis of the surface morphology of non-stoichiometric films SіOx disclosed that dimension of nano-particles arousing as a result of laser annealing is greater (5 - 80 нм) compared with the particles created by thermal annealing (0.3 - 3 нм), but they have a lower surface density. Using volt-ampere measuring, it is stated that electro conductivity of a nano-composite film SiO2(Si) at the thermal annealing rouses as much as four times, whereas rising, at the laser annealing, its intensity makes the electro conductivity substantially worse (tens of times). It s shown that at the low intensities of laser annealing (27 МWt/cm2) density of energetic state of the film not depends from the values of electric field strength, and activation energy of electronic transport rises along with increase of intensity of laser radiation.