Schematic plots of (a) OT, (b) SL, and (c) TL stacking sequences. Upper part shows top view and lower part side view. The interfaces between N1-terminated VN and Ti-terminated TiN are given only. For top views, only the Ti layer nearest to the interface is shown for clarity. The view direction for bottom panels is along [] and the location of interface is marked with horizontal dotted lines. The top and bottom portions of the interface have been omitted.