CRYSTALLINITY OF CE SUBSTITUTED YIG-FILMS PREPARED BY RF-SPUTTERING

The crystallinity of Ce-substituted yttrium iron garnet (Ce-1: YIG) fi lm was studied by measuring X-ray diffraction (XRD) and deformation an d by transmission electron microscope (TEM) observation. The Ce-1:YIG films were prepared on anisotropic etched or unetched GGG and cation d oped GGG (GCGMZG) substrates by RF sputtering. They have a narrow crys tallization region as regards substrate temperature and this region be comes narrower as the O-2 gas flow rate is increased. The XRD measurem ents and TEM observation revealed that crystallized Ce-1:YIG films hav e a multilayered structure except for those on GCGMZG substrates. Thei r layered structure was dependent on their thickness, the substrate tr eatment, the lattice constant difference between the film and the subs trate and the Oa how rate. They also exhibited compressive deformation which originated mainly from the lattice constant difference between the him and the substrate. The crystal growth mechanism of Ce-1:YIG fi lms was considered on the basis of recent work on the growth mechanism of compressively deformed strained semiconductor film.