In this paper, our room-temperature bonding method using activated Si atomic layer demonstrated wafer-level hetero integration of thin film LiNbO₃ on insulator (LNOI) electro-optical modulator arrays on Si. The integration of LNOI photonics with Si, which is a promising platform for LSI, MEMS, and Si photonics, is expected to produce highly functional and multi-functional opto-electro-mechanical platforms.