摘要
We have studied the buried oxide integrity in oxygen plasma-enhanced low-temperature wafer bonding. As observed by cross-sectional scanning electron microscopy, the bonding strength of the oxygen plasma-treated sample is so large that forced separation for a 600 °C bonded wafer takes place at the heterointerface of the thermal oxide and the Si substrate rather than at the oxide-oxide bonding interface. The plasma-enhanced bonding shows good structure property with negligible defects as observed by cross-sectional transmission electron microscopy. From capacitance-voltage measurement, good electrical property is evidenced by the low oxide-charge and interface-trap densities of -2.0×10 10 cm -2 and 3×10 10 eV -1 cm -2 , respectively, from capacitance-voltage measurements.