Heterogeneous nucleation and growth of CrSi2 in sputtered thin films of silicon/silicon nitride

Abstract

Magnetron sputtering is an often favored technique for deposition of thin films of metals, semiconductors and insulators. In the present project, the technique was used to grow thin films of alternating Si and Si3N4 layers on single crystal Si (100) substrates. During one deposition experiment, sputtering also occurred from the stainless steel target clamp rings. Annealing at 1000°C for 2h resulted in crystallization of Cr- and Fe-rich phases. We report on the method to identify and solve the contamination issue. Furthermore, as the contaminant resulted in crystallization of CrSi2, the structures and mechanisms of heterogeneous nucleation and growth of CrSi2 during the sputtering and thermal annealing processes have been investigated. The observed orientation relations between CrSi2 and Si substrate found in this work can provide important information for the study of epitaxial growth CrSi2 system.