No abstract

An enabling material for high density microelectronics technologies, C54-TiSi 2 thin films can be used in many related integrated microsystem technologies to reduce the RC delay and improve the dynamic performance due to its low electrical resistivity and high thermal stability. In this paper, C54-TiSi 2 thin films were prepared for the first time using cathodic arc deposition with rapid thermal annealing. The impact of energetic ion bombardment on the film microstructure and subsequent C49-C54 phase transformation during annealing were studied. The TiSi 2 compound was used as the cathode material and substrate bias was varied to control the ion energy during the film growth. Rutherford backscattering spectrometry and transmission electron microscopy were utilized to characterize the film composition and microstructure. The composition of the resultant TiSi x thin films varied from x=2.4 to x=1.4 when the substrate bias was varied from a floating self-bias to -200V. The films deposited at room temperature were amorphous with a phase separation at the nano scale. The Si atoms were seen to segregate on the boundary of Ti-rich domains and the domain size increased with the magnitude of the substrate bias. For a 90nm-thick TiSi 2 film deposited on a SiO 2 /Si substrate, the kinetics of the C49-C54 phase transformation was studied by measuring the change of film resistivity upon rapid thermal annealing. It was found that the C49-C54 phase transition temperature was higher (>900°C) for the arc-deposited TiSi 2 thin films compared to evaporated or sputtered films. The activation energy of the C49-C54 transformation was calculated to be 6.1±0.2eV.