Surface-Tension Driven Heterogeneous Integration of Thin Film Photonic Devices Using Micro-Contact Printing for Multi-Material Photonic Integrated Circuits

We introduce a surface-tension driven heterogeneous integration of thin film photonic devices using a surface wetting modification. In this process, the combination of a micro-contact printing method and plasma surface modification is used to selectively form a binding liquid on an integration host substrate. With predefined integration areas using the binding liquid, thin film GaAs photodetectors (PDs) are successfully integrated. We have demonstrated the implementation of this integration method by presenting a multi-material photonic integrated structure with integrated GaAs based thin film PDs and a polymer waveguide on a silicon substrate. The measured average misalignment of the integrated PDs was 2.8 μ m from the predefined integration locations. Stable electrical contact between the PDs and the host substrate has been confirmed with dark and photocurrent measurements. The proposed process has the potential towards a low-cost, parallel heterogeneous integration of III-V photonic devices on a silicon platform.