Abstract
A pure aluminum and pure silicon were anodic-bonded to a borosilicate glass. The anodic bonds were studied by cross-sectional TEM. For al/glass, sodium was not completely depleted from a sodium-depleted region of glass. Diffusion paths of aluminum tended to grow into the sodium-depleted region from the metal. The paths were of γ-Al_2O_3. At a higher temperature, the paths grew longer and branched more. The aluminum diffusion accounted for the Al/glass bond formation. For Si/glass, sodium was almost completely depleted from the sodium-depleted region. Several regions that were not well understand existed in the glass near the Si/glass interface. Oxygen was likely to diffuse into silicon from glass, which resulted an amorphous SiO_2 region. It was then concluded that anodic material played key roles in ion-diffusion processes near metal/glass interface during anodic bonding.
