Semiconductor device fabrication method and semiconductor device

A method for fabricating a semiconductor device, the semiconductor device including a capacitor and a support insulator, the capacitor including a cylindrical electrode, the cylindrical electrode extending in a vertical direction,

• the method including forming the cylindrical electrode, the cylindrical electrode comprising upper and lower sections, the lower section having a supported outer surface supported by the support insulator and a roughened inner surface, the upper section upwardly projecting from the support insulator and having an exposed outer surface, the forming of the cylindrical electrode comprising;
• forming an initial cylindrical electrode supported by the support insulator, the initial cylindrical electrode comprising an initial upper section and an initial lower section, the initial upper section and the initial lower section correspond to the upper section and the lower section of the cylindrical electrode, respectively, the initial upper section being supported by the support insulator;
• implanting specific impurities into the initial upper section, the specific impurities serving to prevent the initial upper section from being roughened;
• and
• exposing the initial cylindrical electrode to a roughening process so that the initial lower section is roughened to be the lower section.