Sputtered aluminum nitride-on-insulator for scalable integrated photonics

Aluminum nitride (AlN) is an emerging material platform for integrated photonics. It provides a wide transparency window (ultraviolet to mid-infrared) and enables versatile functionalities such as optical nonlinearities, pyroelectricity or piezoelectricity. While the sputter deposition for AlN thin films on silicon dioxide (SiO2) facilitates scalability and integration with other photonic platforms, accomplishing high-quality sputtered AlN thin films on SiO2 still bears some challenges. In this work we present our approach and progress to tackle this issue targeting co-integration of photonics and micro-electro-mechanical systems (MEMS) on the same platform. Therefore, we provide comprehensive material characteristics for sputtered AlN-on-SiO2 thin films and the fabrication and characterization of thin film AlN-on-SiO2 integrated photonic components targeting a wavelength around 1.55µm. Furthermore, we suggest a design for a piezoelectric MEMS tunable optical power modulator. Our work highlights the potential of a scalable AlN-on-insulator platform for integrated photonics applications.