A novel low temperature direct wafer bonding technology employing vacuum-cavity pre-bonding
is proposed and applied in bonding of InGaAs/Si couple wafers under 300°C and InP/GaAs couple wafers
under 350°C. Aligning accuracy of 0.5μm is achieved. During wafer bonding process the pressure on the
couple wafers is 10MPa. The interface energy is sufficiently high to allow thinning of the wafers down
from 350um to about 100um. And the tensile strength test indicates the bonding energy of bonded samples
is about equal to the bonded samples at 550°C.