Formation and nitridation of vanadium-aluminum intermetallic compounds

V(5)Al(8) and V(3)Al intermetallics have been formed by interdiffusion, by annealing of sputtered V/Al-multilayers at 700 degrees C in vacuo; sapphire (102) was used as substrate. The V/Al intermetallics were nitridated in NH(3) at 900 degrees C for 1 min by RTP (rapid thermal processing). The samples were investigated with XRD (X-ray diffraction), SNMS (secondary neutral mass spectrometry), and AFM (atomic force microscopy). A 5-10 nm thick AlN film (001 textured) was formed by nitridation of V(5)Al(8) (110 textured) and 2-3% nitrogen was incorporated in the V(5)Al(8) bulk. Nitridation of V(3)Al resulted in the formation of VN and AlN. Direct nitridation of V/Al-multilayers showed that near the surface nitridation is faster than intermixing of the V and Al layers. The capability of VN as diffusion barrier for Al could also be shown.