Fig. 1. (Color online) (a) Schematic diagram of the plasma-activated wafer; (b) GaAs and Si wafer bonding; (c) time-dependent curve of annealing temperature at an annealing temperature of 300 ℃.

Fig. 2. (Color online) (a) Before surface activation of Si wafer; (b) after surface activation of Si wafer; (c) before surface activation of GaAs wafer; (d) after surface activation of GaAs wafer; (e) XPS survey on GaAs surface before and after Ar plasma-activation; (f) XPS survey on Si surface before and after Ar plasma-activation.

Fig. 3. (a) Physical image of GaAs/Si bonded wafers; (b) infrared transmission imaging of GaAs/Si bonded wafers; (c) schematic diagram of a GaAs/Si bonding pair cut into 10 × 10 mm² bonded square pieces; (d) relationship diagram of GaAs/Si bonding strength at different annealing temperatures.

Fig. 4. (Color online) (a) SEM image of GaAs/Si bonding interface; (b) the GaAs/Si bonding interface is coated with a protective Pt layer; (c) GaAs/Si sample is thinned; (d) schematic diagram of GaAs/Si bonding interface; (e) the distribution of As element at the bonding interface; (f) the distribution of Ga element at the bonding interface; (g) the distribution of Si element at the bonding interface; (h) elemental composition of amorphous transition layer of GaAs/Si wafers.

Fig. 5. (Color online) (a) Y-direction displacement cloud map; (b) z-direction displacement cloud map; (c) the distribution curve of equivalent stress and wafer diameter; (d) distribution curve of wafer variables and diameter; (e) analysis of electrical characteristics of GaAs/Si bonding interface at different annealing temperatures.