| 摘要 |
PURPOSE:To increase storage capacitance without enlarging the area of a cell while obtaining the cell strong to alpha-rays by adding capacitance between a diffusion region and a gate in the memory storage with structure in which charges are stored into the impurity diffusion region of a transistor for holding memory consisting of a MISFET. CONSTITUTION:A thick field SiO2 film 7 is formed around a P type Si substrate 6, and a gate electrode 3 consisting of polycrystalline Si is formed to the central section of the surface of the substrate 6 surrounded by the film 7 through a gate insulating film. N<+> type source region 1 and drain region 2 are diffused and formed into the substrate 6 on the both sides while using the electrode 3 as a mask, and the whole surface containing the region 1 and the region 2 is coated with an SiO2 film 4. A window is bored being made correspond to the region 1, a polycrystalline Si film 5 as capacitance is coated onto the electrode 3 while being brought into contact with the window and connected to the GND, and the whole surface is coated with an interlayer insulating film 8 composed of PSG. Accordingly, action increasing storage capacitance is generated in the overlapping section of the electrode 3 and the film 5. |
