Research : Surface activated bonding

Schematic of Surface activated bonding based on fast atom beam

III-V/Si wafer bonded by
Surface activated bonding
based on fast atom beam

In order to realize photonic integrated circuits (PICs) consisting of active devices such as lasers and amplifiers, the hybrid integration of Ⅲ-Ⅴ compound semiconductor on silicon-on-insulator (SOI) is considered as one of solutions. Hydrophilic bonding or plasma activated bonding (PAB) are usually used for such hybrid wafer bonding. However, annealing temperature of higher than 150°C and long cooling time are required for achieving high bonding strength, resulting in the thermal stress caused by the difference between thermal expansion coefficients of bonded wafers. To deal with the mentioned problems, surface activated bonding (SAB) based on fast atom beam (FAB) was proposed in recent years, which can realize wafer bonding at room temperature. Thermal expansion between Ⅲ-Ⅴ compound semiconductor and Si could be optimized thanks to this technology, which contribute to fabricate high quality hybrid laser.

school emblem　by chip-on-wafer bonding technique

List of reports

• 1. Yuning Wang, Kumi Nagasaka, Takuya Mitarai, Yoshitaka Ohiso, Tomohiro Amemiya and Nobuhiko Nishiyama, “High-quality InP/SOI heterogeneous material integration by room temperature surface-activated bonding for hybrid photonic devices”, Jpn. J. Appl. Phys., Vol. 59, No.5, p. 052004, April 2020