Homogeneous Chip to Wafer Bonding of InP-Al_2O_3-Si Using UV/O_3 Activation

摘要

A direct chip to wafer bonding of indium phosphide (InP) onto silicon using Al_2O_3 as the intermediate homogenous bonding layer is reported. Intermediate film thickness is varied from 5 to 20 nm and the UV/O_3 activation time is optimized to result in minimal surface roughness and contact angle required for effective direct wafer bonding. TEM characterization of the interface reveals a homogeneously fused Al_2O_3 layer. In addition Al_2O_3 is shown to best emulate the thermal characteristics of direct InP/Si bonding as compared to using SiO_2 as the interfacial bonding layer. Therefore Al_2O_3 is recognized be a highly competent interfacial layer for chip to wafer bonding for integrated photonic application.