| 摘要 |
PURPOSE:To prevent damage of a gate insulating film when forming source and drain thereof in a semiconductor by coating polycrystalline silicon film on the entire surface, implanting impurity ion directly through the polycrystalline silicon film in the state, and further heat treating it. CONSTITUTION:A gate insulating film 22 is formed on the surface of an Si substrate 21. Further, a gate electrode 23 is formed on a gate insulating film 22. Then, a polycrystalline silicon film 25 is formed on the field oxide film 24. Thereafter, the polycrystalline silicon film 25 is implanted with impurity ion directly to the Si substrate 21 therethrough. Further, after this ion implantation, it is annealed with O2 (heat treatment). In this manner, the surface side of the polycrystalline silicon film 25 is formed to polycrystalline silicon oxide film 25', and extension diffusion is executed in the implanted impurity to activate the implanted impurity to form source and drain diffused layers 26 in the desired regions at the surface side of the Si substrate 21 in the periphery of the gate insulating film 22. |
