Ion beam induced intermixing of interface structures in W/Si multilayers

Capped Mo/Si multilayers with improved performance at 304 nm for future solar missions

“…The AFM images indicates a re-organization of the film compatible with what already observed to be the formation of W crystallite; intermixing of W and Si in the top surface of a depth graded ML was also observed with TEM [23]: while the inner bilayers (minimum period 3.33 nm) appear as an amorphous film of Si and W somehow with well define interfaces, the top W/Si bilayer, characterized by a period of around 26 nm, appeared as fully inter-diffused, indicating the possible formation of a W x Si y compound. The same intermixing process was also observed in 4 nm period W/Si multilayer [28]. Crystallization of the top layer as well as intermixing between top layers materials could explain the degradation of the optical performances.…”

Ion-induced interface layer formation in W/Si and WRe/Si multilayers

“…From this graph it is evident that ions inevitably reach the interface between the W layer and the Si layer underneath. This will cause intermixing of the W and Si in the next interface in the multilayer structure [16], which is at most 2 nm deep.…”

Determination of in-depth density profiles of multilayer structures

“…The material combinations W / Si and Mo/ Si were used. W / Si is known to form graded interfaces under ion bombardment, 11 whereas Mo/ Si is known to form silicides 12 under ion bombardment. For this reason we investigated samples with and without Kr + ion bombardment of the high-Z material.…”