Surface Activated Bonding of ALD Al2O3 films

Plasma enhanced ALD Al
2
O
3
films were successfully bonded by surface activated bonding. The increase of O
2
plasma power for deposition promoted the crystallinity of Al
2
O
3
slightly, and the additional H
2
plasma post-treatment improved the hydrophilicity of the film dramatically. The bond strength in humid air was not affected strongly by film deposition parameters, while that in dry N2 was improved by both methods. Water stress corrosion has a big effect on the debonding process resulting in higher bond strength in dry N2. Under the same debonding atmosphere, the bond strength of amorphous Al
2
O
3
films was slightly lower than that of sapphire bonding.