Patent ID: 7019349

Claim:
A semiconductor memory device comprising: a trench capacitor formed in a major surface portion of a semiconductor substrate, the trench capacitor including a storage node electrode provided within a trench that is formed in the major surface portion of the semiconductor substrate, a plate electrode that is disposed to be opposed to the storage node electrode, and a capacitor insulation film that is provided between the storage node electrode and the plate electrode and is formed of a high-dielectric-constant material; an insulated-gate-type field-effect transistor that is formed in the major surface portion of the semiconductor substrate; a contact portion that electrically connects a source or a drain of the insulated-gate-type field-effect transistor and the storage node electrode; and a cap structure formed between the contact portion and upper parts of the storage node electrode, the cap structure including a region lying on the storage node electrode and a region lying on the capacitor insulation film, the region on the capacitor insulation film being thicker than the region on the storage node electrode.