Post-Silicidation Annealing Effects on Electrical and Structural Properties of NiPt Germanosilicide

In this work NiPt germanosilicides were fabricated with 20 nm thick Ni and different Pt layer (3, 6, 9, and 12 nm thick) by rapid thermal annealing at 300 {degree sign}C, and then the post-annealing effects on these samples were investigated in the temperature range between 400 oC to 750 oC. The obtained silicide samples were analyzed using several characterization techniques. Smooth and uniform Ni(Pt) monogermanosilicide films have been observed for all analyzed samples. For annealing temperatures lower than 500 oC the samples exhibited thermal stability with sheet resistances of 10 - 30 Ω/sq, and sheet resistance degradation for annealing temperatures of 500 {degree sign}C and above. Structural transformation of formed silicide to Ge rich Ni(Pt)Si1-uGeu films was found to occurs with increasing of the annealing temperature. Surface analysis revealed morphological instability of germanosilicides and strong tendency for agglomeration and mounds-like structure formation, that leads to an abrupt increase in the sheet resistance.