In order to evaluate the stress intensity factors at the tip of interfacial crack in the non-straight interface such as in semi-conductor device, the M-integral which is path-independent when the interface and the interface and the interfacial crack lie along the radial line is known to be a useful tool. Case of thermal loading can be easily dealt with by modifying the M-integral in the same spirit as Wilson and Yu's for modified M-integral is derived and the value of the modified M-integral is evaluated for the cases of thermal loading and mechanical loading. The geometry, which can model a multilayered structure in semi-conductor device, that is, the structure with thin metal layer and oxide layer on silicon substrate is analyzed.
It is found that the modified M-integral can be easily computed for this problem and it hs potential application for evaluation of stress intensity factors. In contrast to the case of mechanical loading, the energy release rate decreases as the crack length increases approaching the corner point of the interface when the thermal loading is applied.
