SEMICONDUCTOR DEVICE

摘要

PROBLEM TO BE SOLVED: To form a capacitor realizing large size and high voltage resistance of a capacity by enlarging an electrode area for the capacitor without involving the large size of chip size of a semiconductor device. SOLUTION: The inside of an insulation separation trench 6 is filled with an embedded polysilicon 6b introducing an N type impurity. The embedded polysilicon 6b functions as a first electrode part of the capacitor making a side wall oxidation film 6a of the insulation separation trench 6 a dielectric thin film. An N<+> dispersion layer 16 introducing the N type impurity is formed in a monocrystal silicon layer 11 with an element formation area 5 divided by the insulation separation trench 6. The N<+> dispersion layer 16 functions as a second electrode part of the capacitor.