Experimental observation of the confinement of atomic collision cascades during ion sputtering of porous silicon

Results of investigation of the mass spectra of secondary ions sputtered from bulk (continuous) and porous silicon targets with various characteristic core particle dimensions are presented. It has been established that the sputtering of nanostructured Si samples leads to a significant increase in the relative yield of massive cluster ions. This effect is especially pronounced when the characteristic nanoparticle size approaches the range of bombarding ions in the Si target. The obtained results are explained taking into account the confinement of atomic collision cascades.