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SWe have developed thin film zone melting crystallization (ZMC) to fabricate high quality Si thin films for solar cells. We prepared the three-layer structure of SiO2/Si/SiO2 using chemical vapor deposition and Rf sputtering. The Si thin films in the three-layer structure were crystallized by using the ZMC. The Si ZMC film can be separated from the Si wafer by removing the bottom layer of SiO2, and the expensive Si wafer can be reused.We had reported that the defect density measured by electron spin resonance decreased drastically by changing the initial Si film from the poly crystal Si to the amorphous Si. In this paper, we will show the very high quality of ZMC films and will also discuss the mechanism for crystal orientation in Si-ZMC using the crystal orientation map measured by Orientation Image Microscopy (OIM).The different kinds of Si-ZMC films were fabricated (1. normal ZMC films with scanning upper lamp heater, 2. ZMC films melted once and cooled down without scanning, and 3. Quenched ZMC films during scanning). By comparing the OIM images of these ZMC films, we concluded that the crystal orientations seem to be uniformed by the stability at the interface of Si/SiO2 and by the scan of the melting zone.

For the development of a new solar cell material, b-iron silicide (b-FeS2) films were fabricated by using the following two techniques involving the thin film Zone Melting Crystallization (ZMC) method. First, b-FeSi2 was formed by post-annealing ZMC films composed of a-FeSi2. The phase transition from a-FeSi2 to b-FeSi2 was induced by the post-annealing and promoted with Cu. Second, b-FeSi2 was directly formed from the melt without post-annealing by adjusting the power of upper and lower heaters in the ZMC. Results showed that (1) crystal phase of the Fe/Si films could be controlled by adjusting the power of each heater in the ZMC, (2) Cu promoted formation of b-FeSi2 from amorphous in addition to promoting phase transition from a-FeSi2 to b-FeSi2, and (3) crystal phase of ZMC films depended on the dispersion of Cu in the films.