ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
Phase formation in the interfacial reactions of ultrahigh vacuum deposited Ti thin films on (111)Si has been studied by in situ reflected high energy electron diffraction (RHEED) and transmission electron microscopy (TEM). In situ RHEED and high resolution TEM data showed unambiguously that there is considerable intermixing of Ti and Si atoms during Ti deposition. Ti5Si3 was found to be the first nucleated phase followed by Ti5Si4 and TiSi. Ti5Si3, Ti5Si4, TiSi, and C49-TiSi2 along with a-interlayer were found to form in samples annealed at 475 °C for 30 and 60 min. Ti5Si4 was the first silicide phase to disappear followed by Ti5Si3 then TiSi. In samples annealed at 700 °C for 10 min, C54-TiSi2 started to appear. To understand the thermodynamic origin of the phase formation, metastable free energy diagrams at 450–600 °C have been constructed. Ti5Si3 and C49-TiSi2 were found to have the highest and lowest driving force, respectively. On the other hand, Ti5Si4 has the lowest interface energy. The sequence of formation and disappearance of silicide phases is discussed accordingly.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.350441
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