Evaluation of Au-Au bonding after annealing for getter activation -Fabrication of all-sapphire Cs gas cell for miniature atomic clock-

We examined characteristics of Au-Au thin films bonding after annealing for getter activation. From SAM observation, almost whole area was well bonded except defects due to particles. The bonding strength was so high that the bonded specimen was fractured not from the bonding interface but from bulk substrate in tensile test. Even after annealing, Ti/Pt/Au film layers were not diffused into each other. On the other hand, Au crystal grains were recrystallized and continuously connected across Au-Au bonding interface.