| 摘要 |
PURPOSE:To obtain the cell resistive to alpha rays and the dynamic type MOSRAM having high integration density for subject semiconductor device by a method wherein the diffusion layer, to be used as a bit line is buried in a substrate, is connected to the surface of the substrate and the area of a capacity section is enlarged relatively. CONSTITUTION:For instance, after the N<+> diffusion layer 7 to be used as the bit line is ion-implanted in a P type Si substrate 6, a P type epitaxial layer 8 is formed and an N<+> layer 7 is buried in the substrate. Then, after a capacity electrode 2 and a gate electrode 3 have been formed using a double-layer polycrystalline Si technique, an N<+> ion is implanted into the substrate using a thick inter-layer film and the gate electrode 3 as a mask and the connected layer 9, with which the surface and the buried layer are connected, is formed by performing a heat treatment. As the surface of the substrate is not occupied by the wide bit line area, the capacity area can be enlarged with the same area of the cells and this enables to be resistive against the alpha rays. Also, a high integration can be obtained by reducing the area required for the bit line. |
