Building efficient interfacial property with graphene heterogeneous interface

We investigated bonding configurations, failure mechanisms and thermal reliabilities of graphene heterogeneous interfaces with Si and SiC substrates using density functional theory and molecular dynamics simulations. The results show that interfacial covalent bond prefers to form between Si-terminated substrates and strain-released graphene, and the graphene/SiC interface tends to have denser covalent bonds while the interfacial bonding at the graphene/Si interface is stronger. The failure of graphene/Si interface is mainly caused by the debonding of Si-Si bonds connecting to interfacial C-Si bonds, while the graphene/SiC interface mainly fails due to the failure of graphene. The higher interfacial bonding density can enhance the interfacial strength, but the strength of graphene will be weakened if too many interfacial covalent bonds are involved, so the stronger interfacial bonding and the less weakened strength of graphene are responsible for the better thermal reliability of graphene/Si interface. Proper thermal shock treatment is found effective to enhance bonding strength of the two graphene/semiconductor interfaces and improve their interfacial thermal reliabilities. This work is hoped to help promote the reliability design of graphene heterogeneous interface for related micro/nano semiconductor devices.