Nucleation, Transformation and Agglomeration of C54 Phase Titanium Disilicide

Abstract

AbstractThe transformation of TiSi2from the C49 phase to the C54 crystallographic phase is an irreversible, polymorphic transformation that occurs by a nucleation and growth process. Typical of polymorphic transformations, the transition occurs readily once a stable embryo of the thermodynamically favored phase is formed. Future VLSI applications requiring control of the resistivity and thermodynamic stability of thin TiSi2films formed on submicron features will necessitate understanding this nucleation and transformation process to a greater extent. We have found that the C54 phase nucleation site density, the resulting microstructure and thermal stability of the film can be strongly influenced by the initial silicide formation conditions. Rapid thermal processing (RTP) has been found to offer a significant advantage over conventional furnace annealing for the silicide formation process.