Semiconductor memory device with cap structure and method of manufacturing the same

摘要

A semiconductor memory device includes a trench capacitor formed in a major surface portion of a semiconductor substrate. The trench capacitor includes a storage node electrode provided within a trench formed in the major surface portion of substrate, a plate electrode disposed opposed to the storage node electrode, and a capacitor insulation film provided between the storage node electrode and plate electrode and formed of high-dielectric-constant material. The memory device further includes an insulated-gate field-effect transistor formed in the major surface portion of substrate, a contact portion that electrically connects a source or drain of the IGFET and the storage node electrode, and a cap structure formed between the contact portion and upper parts of the storage node electrode.