Published online by Cambridge University Press: 21 March 2011
Heavy metal gettering capability on ELTRAN® was studied by controlling surface treatments for handle wafer prior to wafer bonding. Hydrophobic bonding pre-treatments wafer had much higher heavy metal gettering capability at bonding interface than hydrophilic wafer. In the case of hydrophilic bonding pre-treatments, atomically flat bonding interface was observed by cross-sectional TEM. On the other hand, in the case of hydrophobic bonding pre-treatments, “nano gaps” were observed at bonding interface. We concluded that these differences in the structure at the bonding interface caused the difference in the gettering capability. It is possible to control gettering capability by no additional steps in SOI wafer process.