The effect of ion beam mixing on MoSi 2 formation

Abstract

Thin Mo films on Si were mixed by As * ion bombardment at room temperature. This results in an amorphous intermixed layer of varying composition and, at greater depth, in the amorphization of silicon. The formation of MoSi 2 from these implanted structures by thermal reaction has been studied by glancing angle Rutherford backscattering and in situ annealing. These experiments show that ion beam mixing of the interface disperses the interfacial oxide, which is present between Mo and Si and initially a homogeneous reaction occurs. However, when the amorphized silicon has regrown epitaxially, the reaction becomes inhomogeneous or even stops. The dispersed oxygen is apparently snowploughed in front of the interface of amorphous and crystalline silicon leading to a restoration of the oxide barrier.