Stress Relaxation Behaviors of Monocrystalline Silicon Coated with Amorphous SiO2 Film: A Molecular Dynamics Study

Long-lasting constant loading commonly exists in silicon-based microelectronic contact, as well as the chemical mechanical polishing area. In this work, the stress relaxation analysis of single crystal silicon coated with an amorphous SiO2 film is performed by varying the maximum indentation depth using molecular dynamics simulation. It is found that during holding, the applied indentation force declines sharply at the beginning and then steadily towards the end of the holding period. The stress relaxation amount of bilayer composites increases as the maximum indentation depth increases. It is also found that the deformation features of SiO2 film and silicon substrate during holding are inherited from the loading process. The SiO2 film during holding is further densified when the maximum indentation depth is equal to or less than a certain value (5.5 nm for the 0.8-nm film). The amount of generated phases and phase distributions of silicon substrate during holding are affected by the plastic deformation of silicon during loading.