Study for Symmetrical Bonded Structure Canceling Thermal Stresses to Realize Wafer Bonding and Layer Transfer of Dissimilar Materials (Continuing for the Second Year Study)

Due toe lattice mismatch (>5%), it is not possible to directly epitaxy a no point defects, nodislocations, perfect crystallization thin film. Hence, this study will propose a research plan to cutand transfer a thin film from a substrate onto another dissimilar material substrate. In performing thedissimilar material wafer bonding, the key is to avoid the huge thermal stresses that will destruct thebonded wafer pair during the cooling period generated in the annealing step for enhancing thebonding strength. We create a symmetrical bonding structure to cancel the thermal stresses and torealize the direct wafer bonding for dissimilar material wafer pair without the additions of glue orbondable interlayer. The initial anticipation is to increase the anneal temperature to 300°C or aboverequired for Smart-Cut process but reserve the GaAs/Si wafer pair away from damages. Then thenext anticipation is to transfer a thin film from a substrate onto another dissimilar substrate. Thefirst-year goal of this study is to make a complete 4” (10 cm) GaAs/Si bonded wafer pair through300-400°C annealing achieved by appropriate control parameters and material selection. Thesecond-year goal is to perform the Smart-Cut process using multi-thermal-stage, 5×1016 ~ 1×1017/cm2hydrogen implantation to fabricate single crystal ultra-thin GaAs film on Si wafer after 300 ~ 400°Cannealing. The GaAs on Si can be a great substrate, which integrates optoelectronic andmicroelectronic devices.