Surface Contamination Effects on Bonding Performance in Atomic Diffusion Bonding of Wafers using Amorphous Si Thin Films

Room-temperature bonding using 20-nm thick amorphous Si films was studied as a function of waiting time t w in vacuum of 1.0 × 10−6 Pa between film deposition and bonding. Bonding strength decreased suddenly at t w greater than 3.6 × 103 s, which differed from behavior observed using Ti films.