US Patent 7291881 Bit line structure and method of fabrication

The invention relates to a bit line structure having a surface bit line (DLx) and a buried bit line (SLx), the buried bit line (SLx) being formed in a trench with a trench insulation layer (6) and being connected to doping regions (10) with which contact is to be made via a covering connecting layer (12) and a self-aligning terminal layer (13) in an upper partial region of the trench.