Low resistivity C54 phase TiSi₂ films synthesized by a novel two-step method

Synthesis and growth properties of the TiSi₂ film on a Si (001) substrate are investigated. A novel two-step method is used for deposition of the C54 phase TiSi₂ film with low resistivity. The first step is the formation of the C49 phase TiSi₂ at a relative low substrate temperature of 400° C, followed by rapid thermal annealing process at 850° C in N₂ for the formation of the C54 phase TiSi₂ as the second step. Finally, selective wet, etching is employed to remove the un-reaction Ti on the surface and the low resistivity C54 TiSi₂ film can be obtained. The films deposited under various parameters are evaluated by scanning electron microscopy, x-ray diffraction and the resistivity measurement. Compared with other sputtering technologies used commonly for TiSi₂ synthesis, this two-step method has apparent advantages such as the mild synthesis temperature and the high purity of the final product with low resistivity, uniform large area and improving surface roughness. In addition, the film also shows that the low coefficient of resistivity-temperature appears in the temperature range from 20° C to 800° C.