| 摘要 |
PURPOSE:To contrive to enhance strength and to improve integration degree by surrounding most of the capacitor part with an insulation film, interposing no part of a semiconductor substrate between adjacent capacitors, and deepening grooves formed over the substrate under an intercell isolating insulation film. CONSTITUTION:In the dynamic RAM memory cell, the capacitor part is partly embedded in a groove 19 so as to creep along the intercell isolating insulation film 12 and along a thermal oxide film 20 formed in the substrate 11 thereunder. The other part is composed of a gate electrode 21 of a cell plate spreading over many memory cells along the insulation film 12, a capacitor gate oxide film 22 formed over the surface of this gate electrode 21, and a capacitor gate electrode 24 formed on the capacitor gate oxide film 22 and connected to part of the substrate 11. This dRAM increases the effective capacitor surface area by utilizing the shape of the grooves 19 formed over the intercell isolating insulation film 12 and the substrate 11 thereunder. Most of the capacitor part is surrounded with insulation films, i.e. the intercell isolating insulation film 12, thermal oxide film 290, and CVD oxide film 25. |
