Phase formation and electronic structure peculiarities in the Al$_{1-x}$Si$_{x}$ film composites under the conditions of magnetron and ion-beam sputtering

The peculiarities of the phase composition and electronic structure of aluminum–silicon composite films near the Al$_{0.75}$Si$_{0.25}$ composition obtained by the magnetron and ion-beam sputtering methods on a Si(100) silicon substrate are studied using the X-ray diffraction techniques and ultrasoft X-ray emission spectroscopy. In addition to silicon nanocrystals of about 25 nm in size, an ordered solid solution corresponding to the previously unknown Al$_3$Si phase is formed in magnetron sputtering on a polycrystalline Al matrix. Films obtained by ion-beam sputtering of the composite target are found to be monophasic and contained only one phase of an ordered solid solution of aluminum silicide Al$_3$Si of the Pm3m cubic system with the primitive cell parameter $a$ = 4.085 $\mathring{\mathrm{A}}$. However, subsequent pulsed photon annealing of the composite with different radiation doses from 145 to 216 J/cm$^2$ gives rise to the partial decomposition of the Al$_3$Si phase with the formation of free metallic aluminum and silicon nanocrystals with sizes in the range from 50 to 100 nm, depending on the pulsed photon radiation dose.