Solid phase reaction of molybdenumhyphen;nickel alloy thin films with silicon

摘要

Solid phase reaction behavior of polycrystalline and amorphous alloys of MoNix(x=12, 20, and 88) with silicon in the temperature range 500ndash;700thinsp;deg;C has been studied by glancing angle xhyphen;ray diffraction and Auger electron spectroscopy techniques. Two types of reaction mechanisms are observed in these alloy/silicon reactions and both are controlled by the composition of the refractory metal component. In molybdenumhyphen;rich polycrystalline alloy (Mo88Ni12) the reaction at 500thinsp;deg;C occurs due to outhyphen;diffusion of nickel from the alloy, while at 550thinsp;deg;C the reaction between the alloy and silicon mainly occurs due to inhyphen;diffusion of silicon. On the other hand, in nickelhyphen;rich alloy (Mo12Ni88), the reaction at 500thinsp;deg;C is dominated by nickel outhyphen;diffusion. The amorphous alloy (Mo80Ni20) was found to be stable on silicon up to 500thinsp;deg;C and a reaction at 550thinsp;deg;C occurs due to crystallization followed by outhyphen;diffusion of nickel and large amounts of silicon inhyphen;diffusion. In all these alloy/silicon reactions, a macroscopic phase separation between MoSi2and NiSi or NiSi2is observed and results in a twohyphen;layer structure consisting of lsqb;MoSi2+NiSi(or NiSi2)rsqb;/NiSi (or NiSi2)/Si(100).