A semiconductor device and method for fabricating the same. The semiconductor device comprises a capacitor including a semiconductor substrate having a first conductive type well; a first trench formed in the semiconductor substrate; a plate electrode formed on the first trench; a capacitor insulating film formed on the plate electrode; and a storage node electrode formed in the first trench. The transistor includes a first insulating film for planarization formed on the storage node electrode; a second trench formed in the portion of the first conductive type well, which does not correspond to the first trench; a gate insulating film formed on the second trench; a gate electrode formed on the portion of the gate insulating film, located on the second trench; and drain and source regions formed on the upper and lower portions of the first conductive type well, respectively, which corresponds to the sidewall of the second trench.
