Patent ID: 7276750

Claim:
A semiconductor device comprising: a semiconductor substrate having a trench; a capacitor having a storage electrode and arranged in a lower portion of the trench; a collar oxide film arranged on a portion of a side of the trench above the capacitor; a storage node arranged on a bottom portion of a side of the collar oxide film in an upper portion of the trench and electrically connected to the storage electrode; a select transistor provided on a surface of the semiconductor substrate and having a source region in contact with the trench; a spacer arranged on a top portion of the side of the collar oxide film, the top portion of the side of the collar oxide film being above the storage node and disposed between the spacer and a side of the source region, the spacer consisting essentially of a silicon nitride film; and a surface strap contact arranged upon the spacer, the source region, and the storage node.