Hybrid aluminum nitride and silicon devices for integrated photonics

Aluminum nitride has advantages ranging from a large transparency window to its high thermal and chemical resistance, piezoelectric effect, electro-optic property, and compatibility with the complementary metal-oxide-semiconductor fabrication process. We propose a hybrid aluminum nitride and silicon platform for integrated photonics. Hybrid aluminum nitride–silicon basic photonic devices, including the multimode interferometer, Mach–Zehnder interferometer, and micro-ring resonator, are designed and fabricated. The measured extinction ratio is > 22 dB and the insertion loss is < 1 dB in a wavelength range of 40 nm for the Mach–Zehnder interferometer. The extinction ratio and intrinsic quality factor of the fabricated micro-ring resonator are > 16 dB and 43,300, respectively. The demonstrated hybrid integrated photonic platform is promising for realizing ultralow-power optical switching and electro-optic modulation based on the piezoelectric and electro-optic effects of aluminum nitride thin films.