The effects of interfacial oxide layers on the Al-induced crystallization (AIC) of amorphous Si 1Àx Ge x (x: 0 -1) films on an insulator at a low temperature (<500 C) have been investigated. In the case of Si, the inversion of the Si/Al layers was achieved for samples with and without interfacial oxide layers between the Si and Al layers. In addition, it was found that the existence of interfacial oxide layers was required to obtain large grain ($100 mm) polycrystalline Si with a (111) orientation. However, in the case of SiGe, the interfacial oxide layers significantly retarded AIC growth. Consequently, layer exchange occurred inhomogenously, which resulted in inhomogenous crystallization even after a long annealing time (410 C, 100 h). To solve this problem, the effects of interfacial oxide thickness on AIC growth were investigated. As a result, complete layer exchange was achieved for samples with the whole Ge fractions (x: 0 -1) by controlling the air exposure time. A qualitative model is presented.

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Al-induced crystallization (AIC) of Si and Ge has been comparatively investigated to realize poly-Si and poly-Ge layers on insulating films. For amorphous-Si (a-Si)/Al stacked structures, poly-Si oriented to the (111) direction was formed after annealing (450oC, 40h), and inversion of Si/Al layers occurred completely. On the other hand, poly-Ge with random orientations was formed in the local areas (diameter: 20 μm) of the Al layers after annealing (350oC, 150h) for a-Ge/Al stacked structures. In addition, inversion of Ge/Al layers did not occur. Understanding of AIC of Ge is necessary to establish a new technique for formation of high-quality poly-SiGe at low temperatures.