Tantalum nitride as a diffusion barrier between Pd sub 2 Si or CoSi sub 2 and aluminum.

Reactively sputtered tantalum nitride (Ta sub 2 N) has been investigated as a diffusion barrier between Pd sub 2 Si and aluminum and CoSi sub 2 and Al. Ta sub 2 N is found to be excellent metallurgical diffusion barrier for the two systems up to 555C, with no intermixing observed in Rutherford backscattering and Auger electron spectroscopic studies. Schottky barrier devices n-Si/Pd sub 2 Si/Ta sub 2 N/Al were excellent and showed no deterioration after annealing at 500C. However, similar devices with CoSi sub 2 contacts and Ta sub 2 N barrier showed a creation of high contact resistance between the silicide and the as- deposited nitride.