CHARACTERIZATION OF TITANIUM SILICIDE BY RAMAN-SPECTROSCOPY FOR SUBMICRON IC PROCESSING

The formation of the low resistivity C54 phase of titanium silicide (T iSi2) used in submicron IC technology was studied using Raman spectros copy. TiSi2 on both pad areas (100 x 100 mu m(2)) as well as polycryst alline and amorphous silicon narrow Lines (line widths: 0.35 to 1.0 mu m) were formed under various rapid thermal annealing temperatures. Th e results showed that Raman spectroscopy could accurately identify the temperature ranges of the formation, transformation and agglomeration of TiSi2. Qualitative analysis confirmed the difficulty of forming C5 4 phase TiSi2 on narrow polycrystalline lines. TiSi2 was also found to form at a lower annealing temperature on amorphous Si than on polycry stalline Si, which is attributed to the random nature of amorphous Si, although its degradation also occurs earlier. These results demonstra te the applicability of Raman spectroscopy for characterizing TiSi2 us ed in sub-half-micron IC processing. 1998 Published by Elsevier Scienc e B.V. All rights reserved.