... Curvature of interfaci crack front determ ial fr mined for t BD film with the ms thickness t anging from 100 to 100 m 00nm [2] 90 Chapter C Fig F 4. 16: FESEM plan ne-view ima ages of the wedge inden ... tionship bet tween the cu urvature of crack front and the f t film thickne As can be seen i Fig.4. 16( for a B film ≤ 100 nm th f ess n in (a), BD hick, the interfacial c i crack front is very ... contrast, w when the BD film B thickness is increased t about 500 nm or mor (Fig.4. 16 and 4. 16( d)), the cu t to re 6( c) urvature reaches a pl r lateau at ab bout 0.51 µm-1 (Fig.4.1 and the delaminati...