Integration of magneto-optical garnet films by metal-organic chemical vapor deposition

This paper presents a novel technique for integrating yttrium iron garnets, namely Ce:YIG, onto semiconductor platforms using metal-organic chemical vapor deposition (MOCVD). Large amounts of cerium (Ce) could be incorporated into the garnet structure because of the nonequilibrium nature of the technique. The method can alloy up to 54% Ce, thereby increasing the refractive index and enhancing the Faraday rotation of the YIG films. Faraday rotations as high as 0.4°/μm at 1.3 μm were achieved in MOCVD-grown garnets, exceeding the rotations of bismuth-doped YIG films (0.15°/μm at 1.3 μm) grown by liquid-phase epitaxy. The easy axis of magnetization is within the plane of the films. When the garnet films were sputtered onto (100) magnesia (MgO) buffer layers, their hysteresis loops indicated that they were isotropic.