Characterization of titanium silicide by Raman spectroscopy for submicron IC processing

Abstract The formation of the low resistivity C54 phase of titanium silicide (TiSi 2 ) used in submicron IC technology was studied using Raman spectroscopy. TiSi 2 on both pad areas (100×100 μm 2 ) as well as polycrystalline and amorphous silicon narrow lines (line widths: 0.35 to 1.0 μm) were formed under various rapid thermal annealing temperatures. The results showed that Raman spectroscopy could accurately identify the temperature ranges of the formation, transformation and agglomeration of TiSi 2 . Qualitative analysis confirmed the difficulty of forming C54 phase TiSi 2 on narrow polycrystalline lines. TiSi 2 was also found to form at a lower annealing temperature on amorphous Si than on polycrystalline Si, which is attributed to the random nature of amorphous Si, although its degradation also occurs earlier. These results demonstrate the applicability of Raman spectroscopy for characterizing TiSi 2 used in sub-half-micron IC processing.