Monitoring of TiSi2 formation on narrow polycrystalline silicon lines using Raman spectroscopy

Micro-Raman spectroscopy is used to monitor titanium silicide (TiSi
₂
) formation on narrow undoped polycrystalline silicon lines. Linewidths varying from 1.0 μm down to 0.35 μm, with silicidation by rapid thermal anneal (RTA) temperature ranging between 780/spl deg/C and 1020/spl deg/C were analyzed. Phase changes between C49 and C54-TiSi
₂
phases were clearly observed. Results demonstrate that analysis of the C54-TiSi
₂
Raman peak intensity allowed fast and nondestructive estimation of the process window for low resistivity C54-TiSi
₂
formation. Comparison with sheet resistivity measurements showed that micro-Raman scattering provides a complimentary means to electrical analysis for the study of TiSi
₂
formation.