Thickness Dependence Of C-54tisi(2) Phase Formation In Tin/Ti/Si(100) Thin Film Structures Annealed In Nitrogen Ambient

One of the most used metallization schemes on silicon is the TiN/TiSi2/Si structure, since it has taken advantage of good electrical contact between Si and TiSi2 and the property as a diffusion barrier of TiN. In the present study, this structure has been realized by sputter depositing different layers of TiN/Ti onto silicon (100) substrate and annealing them in nitrogen ambient at different temperatures. Transmission electron microscopy as well as grazing incidence x-ray diffraction have been employed to study the morphology and the crystallographic properties of the formed layers. Initial stage of the C-49 TiSi2 formation has been investigated at 590 degrees C and complete formation of C-54 TiSi2 phase observed at 710 degrees C for higher thickness samples. Our attention has been focused on the TiN/TiSi2/Si structures obtained after annealing the deposited films at 710 and 850 degrees C. We demonstrate that at the annealing temperature of 850 degrees C as the thickness of the TiN/Ti deposited films is decreased from 600/560 to 175/30 Angstrom, the formation of TiSi2 (C-54) phase is almost inhibited due to a faster consumption of Ti in the formation of TiN. (C) 1999 American Institute of Physics. [S0021-8979(99)02020-4].