Thermo-mechanical analysis and interfacial energy release rate estimation for metal-insulator-metal capacitor device

The metal-insulator-metal (MIM) capacitor device is the most popular structure that has been massively used in system circuit designs in IC and PCB processes. The characteristics of system will be changed and electrical performances will be impaired if large deformations are resulted in MIM capacitor device. Therefore, the concerns of reliability for MIM capacitor devices are very important issues. For the purpose of realizing the probability of delamination of GaAs/Si"3N"4 interface in MIM capacitor device, the four-point bend experiment is employed to evaluate the critical energy release rate, which is an important index to determine the possibility of inducing interfacial delamination. Moreover, to validate the phenomenon of delamination in MIM capacitor device, the finite element analysis (FEA) and modified virtual crack closure technique (MVCCT) are adopted. Thermo-mechanical stress distributions in MIM capacitor device that under reliability test conditions can be illustrated. The results show that the maximum stress occurs at the layer of Si"3N"4 or its corresponding interfaces. These stress concentration areas are critical places to be fractured. Furthermore, the designs of experiments (DOE) analysis is also employed to have better geometric parameters in MIM capacitor device to reduce stresses. It is believed that this study will be useful design guideline to prevent the phenomenon of interfacial delamination and enhance the reliability.