An 8-inch Wafer Bonding Apparatus with Ultra-High Alignment Accuracy Using Surface Activated Bonding (SAB) Concept

An ultra high precision alignment and robot-controlled wafer bonding machine has been developed for the bonding of different sizes of wafers ranging up to 8 inches diameter. A bonding accuracy of ±0.5 µm has achieved through the X, Y, and 6 axis alignments. 8-inch diameter silicon wafers were successfully bonded by the surface activated bonding (SAB) process at room temperature for the first time. Preliminary investigations across the interface using an infrared camera show that no bubbles are visibly present in the bonding region.