Simple and low-temperature vacuum packaging process by using Au/Ta/Ti metal multilayer

A Au/Ta/Ti metal multilayer was developed to improve the high vacuum packaging process for microdevice fabrication. This study revealed that the wafer coated with the Au/Ta/Ti layer could form direct bonding and absorb residual gas. We investigated the effect of Ta layer thickness on the diffusion of Ti atoms. The Au/Ta/Ti metal multilayers were successfully bonded after a degassing process when the Ta barrier layer is thicker than 1.5 nm. Moreover, the Au/Ta/Ti metal film effectively absorbed the residual gas molecules by annealing at 350 degrees C. As the annealing temperature for the gas gettering is lower than the previous reports, the Au/Ta/Ti metal multilayer could be useful for the future vacuum packaging process.

Automated summary

An Au/Ta/Ti metal multilayer was developed to improve the high vacuum packaging process for microdevice fabrication. The study showed that the coated wafer could form direct bonding and absorb residual gas, and investigated the effect of Ta layer thickness on Ti atom diffusion.