SUPPRESSING THE FORMATION OF CONE STRUCTURES IN CHEMICAL-VAPOR-DEPOSITED ALUMINUM NITRIDE TITANIUM NITRIDE FILMS/

Cone structures are sometimes observed in aluminum nitride/titanium ni tride (AlN/TiN) composite films formed by chemical vapor deposition (C VD). In this study, we determined the formation mechanism of cone stru ctures by looking at such films deposited on Si substrates. We found t hat the mechanism can be explained by changes in the deposition rate d ue to composition differences in the growing surfaces, rather than by inhomogeneities in the original substrate surface. We then used this d iscovery to develop a technique to suppress cone structure formation, i.e., deposition of an interlayer before the deposition of the composi te, To validate our technique, we then successfully suppressed the for mation of cone structures in AlN/TiN films by depositing a TiN interla yer on the substrate before the deposition of AlN/TiN.