| 摘要 |
PURPOSE:To prevent a leakage current between trenches by a method wherein a high-concentration impurity layer whose conductivity type is identical to that of a silicon substrate is formed on side faces of the trenches faced at a part where the distance between the trenches becomes extremely near and an impurity layer of an opposite conductivity type is formed on other side faces of the trenches. CONSTITUTION:A field oxide film 11 is formed on a p-type silicon substrate 10; after that, the substrate 10 in one part of a device region partitioned by the film 11 is etched; trenches 13 are formed. Then, ions of boron are implanted into the side of short sides of side faces of the trenches where the trenches 13 are faced comparatively near; a p<+> layer 14 is formed. After that, a thermal oxide film 16 of 100Angstrom is formed; after that, polycrystalline silicon 17 as a gate electrode is deposited to be 3000Angstrom ; a trench capacitor 16 can be formed. By this setup, a leakage current on the trench side can be prevented; the trench capacitor of a comparatively large capacitance value can be formed. |
