Titanium nitride as a diffusion barrier between nickel silicide and aluminum
The diffusion barrier properties of titanium nitride between nickel silicide and aluminum have been investigated in NiSi Schottky contacts on silicon for annealing temperatures of 400–600°C. No interaction between the metals of the contact structure was detected by backscattering spectrometry, even at 600°C. The electron barrier height of Schottky diodes stays constant at ϕBn = 0.67 ± 0.01 upon thermal annealing in vacuum at 500°C for 2 h . The ideality factor is n = 1.01. After 4 h, ϕ Bn decreases by about 10 mV and n rises to 1.0 6. The diodes degrade after annealing at 550°C or 600°C for 30 min.