Effect of multi-cycle annealing on the C49-C54 phase transformation in TiSi₂ thin film

In this paper, the multi-cycle rapid thermal annealing process was proposed as an alternative method to the conventional annealing process for TiSi₂ formation for the first time. Our experimental results and analysis showed that by using this method, some physical defects that act as the nucleus sites for the C49 phase formation can be induced into the Ti/Si interface due to the thermal mismatch between Ti and Si. As a result, the number of the C49 grains increased and the C49 grain size became smaller. With the shrinking of the C49 grain size, more triple junction sites for the C54 phase to nucleate will be contained in the C49 grain boundaries and an easy C49-C54 phase transformation can be expected. The enhancement of the low-resistivity C54 phase formation finally makes the reduction in sheet resistance (R_s) possible. These results are beneficial because the reduction of R_s can be achieved without increasing the annealing temperature or extending the holding time.