Do Van Truong

Cohesive Zone Model Applied to Creep Crack Initiation at an Interface Edge between Submicron Thick Films

A crack initiates at an interface edge between submicron thick films and leads to the malfunction of microelectronic devices. In this study, the cohesive zone model method with a cohesive law based on the damage mechanics concept is developed to simulate the creep crack initiation at an interface edge between tin and silicon films. Experiments on delamination at the Sn/Si interface using a micro-cantilever bend specimen were conducted. The cohesive law is applied to the elements in the UEL user subroutine in the finite element code ABAQUS. The parameters characterizing the cohesive law are calibrated by fitting displacement-time curves obtained by experiments and FEM simulations. It is revealed that the order of stress singularity increases with time and has a significant jump in its value at the crack initiation.

Simulation of Crack Initiation at the Interface Edge Between Sub-Micron Thick Films Under Creep by Cohesive Zone Model

Delamination between sub-micron thick films is initiated at an interface edge due to creep deformation, and leads to the malfunction of microelectronic devices. In this study, the cohesive zone model approach with a cohesive law based on damage mechanics was developed to simulate crack initiation process at an interface edge between film layers under creep. Delamination experiments using a micro-cantilever bend specimen with a Sn/Si interface were conducted. The parameters charactering the cohesive law were calibrated by fitting displacement-time curves obtained by experiments and simulations. In addition, the order of the stress singularity, which increases with time and has a significant jump in its value at the crack initiation, was investigated.Copyright