| 摘要 |
PURPOSE:To provide high mobility, by constituting a double-gate electrode films with polycrystalline silicon, N<+> type amorphous silicon, an N<+> type amorphous germanium and the like, projecting optical energy, and increasing the diameter of the crystal grain of a polycrystalline silicon film, which is an active layer. CONSTITUTION:Double-gate electrode films 6a and 6a are formed as follows: one or a plurality of layers of polycrystalline silicon; an N<+> type amorphous silicon, an N<+> type amorphous germanium and alloy thereof are laminated. Optical energy 5 is projected from the upper part of the laminated bodies of the overlapped double-gate electrode films 6a and 6b, a gate insulating film 3 and a polycrystalline silicon film 4, and annealing is performed. Then, the double-gate electrode films 6a and 6b are heated. The polycrystalline silicon film 4 is heated by the conduction of the heat, and crystallization occurs. After the annealing, an interlayer insulating film 7 is formed. Then source and drain electrodes 8 and 9 are formed, and a double-gate thin film transistor is formed. |
