Abstract
TaSi and TaSiN with a various composition of Ta, Si, and N are fabricated in Ar or Ar/N2 gas mixtures by radio frequency reactive sputtering deposition. Both TaSi and TaSiN films are annealed at 950℃for 30 seconds in nitrogen ambient. The resistivity, chemical composition, crystalline microstructure, diffraction pattern and bonding are investigated by four probe point, Auger, XRD, TEM, and XPS. The diffusion barrier behavior are studied using leakage current and capacitance-voltage. According to those measure, we try to find the optimum condition of diffusion barrier. TaSiN with large Si/Ta ratio has higher resistivity and better diffusion barrier performance. The resistivity of TaSiN AR with Si/Ta ratio 2.3 is 2000□ □-cm and remains thermally stable after annealing 550 ℃. According to XRD and TEM pictures, TaSi is amorphous. And XPS indicates the bonding of Ta-Si. We believe an amorphous TaSi is formed after deposition . The resistivity of TaSi is 200□ □-cm and amorphous TaSi with integration of low k material remains thermally stable after annealing 450 ℃