| 摘要 |
PURPOSE:To prevent the occurrence of a leakage current and a soft error occurring between capacitors due to the high integration of a memory cell by a method wherein the second element isolation insulating film is used to isolate each of capacitors, and the first impurity layer of the second conductivity type having fixed potential to be used in common, is provided on the side of the first conductive type semiconductor substrate as the plate electrode of a plurality of capacitors. CONSTITUTION:On the side of the semiconductor substrate 301 of the first conductive type, a plate electrode 305 formed by the first impurity layer of the second conductivity type, which becomes a fixed potential to be used in common between each capacitor, is provided. Accordingly, even when the electric charge accumulated on the side of the common plate electrode 305 is neutralized by the carrier generated by the alpha rays and the like which are made incident on the deep part of the substrate 301, the potential of said plate electrode can be maintained constant. As a result, the generation of a soft error can be prevented. Also, as the section between all the protruding parts including protruding parts 302a and 302b and also the section between all capacitor electrodes including capacitor electrodes 317a and 317b are insulated by CVD-SiO2 film 321 which is buried in a groove 303 too, the occurrence of a leakage current between the capacitors can be prevented. |
