In this paper, fabrication of beta-ironsilicide (beta -FeSi2)-base metal-insulator-semiconductor diode devices is described. beta -FeSi2 films have been prepared by co-sputtering of Fe and Si followed by thermal annealing. The [2 0 2] X-ray diffraction peak of beta -FeSi2 was observed at 2 theta = 29 degrees when both the Fe-Si chemical composition and annealing temperature were optimized. The prepared beta -FeSi2 films have been thermally oxidized in an O-2 gas atmosphere. Using the techniques above, we fabricated A1/oxidized-FeSi2/beta -FeSi2/p-Si structured devices, which displayed diode properties.