Fig. 1. Main components of CMP

Fig. 2. Schematic diagram of CMP working principle

Fig. 3. Fixture design and working diagram for CMP of 2 inch InP wafer

Fig. 4. CMP actual effect of initial 2-inch InP wafer

Fig. 5. Improved InP wafer fixture and CMP working diagram

Fig. 6. Comparison of CMP removal rate between edge and center of InP wafer

Fig. 7. Prominent of Cu pillar on surface of InP wafer

Fig. 8. Bonding of InP wafer with 8-inch Si wafer

Fig. 9. Cu pillar below surface of InP wafer

Fig. 10. Morphology of Cu pillars at center and edge of InP wafer

Fig. 11. AFM image of 2 inch InP wafer surface

Fig. 12. Surface topography of 2-inch InP wafer after CMP

Fig. 13. Bonding results of 2-inch InP wafer with 8-inch Si wafer

Fig. 14. Morphology of single Cu pillar after annealing of InP wafer