NOVELTY - A stacked structure of amorphous silicon (a-Si) film and conductive film is formed. The stacked structure is then subjected to a varying or an alternating magnetic field to heat the stacked structure to cause a crystallization of the amorphous silicon film by heat transfer from the conductive film to the amorphous silicon film.    USE - Method of crystallizing undoped or lightly doped amorphous silicon film used for fabricating coplanar top gate thin film transistor (TFT) structure and fabricating staggered thin film transistor structure, and for forming crystalline silicon thin film solar cell (all claimed). Can also be used for liquid crystal display, and organic light emitting diode display.    ADVANTAGE - The undoped or lightly doped amorphous silicon film is efficiently crystallized.    DETAILED DESCRIPTION - A stacked structure of amorphous silicon (a-Si) film and conductive film is formed. The stacked structure is then subjected to a varying or an alternating magnetic field to heat the stacked structure to cause a crystallization of the amorphous silicon film by heat transfer from the conductive film to the amorphous silicon film. The conductive film comprises at least one layer chosen from p-type doped amorphous silicon layer (a), p-type doped microcrystalline silicone layer (b), n-type doped amorphous silicon layer (c), n-type doped microcrystalline silicon layer (d), metal layer (e), graphite layer (f), layer (g) formed of magnetic material, transparent conductor layer (h), layer (i) comprising iron, composite layer (j) comprising at least one material from (a-i), and any combination (k) of (a-j). The conductive film alternately comprises at least one doped silicon layer formed by deposition by flowing dopant containing gases with silicon forming gases, or at least one doped silicon layer formed by implanting dopant atoms into the amorphous silicon film. The dopant is chosen from boron, phosphorus, arsenic, antimony, indium, gallium, or aluminum. An INDEPENDENT CLAIM is included for method of crystallizing an amorphous silicon layer.