For fabricating a flash memory cell, a dummy gate structure is formed on an active device area of a semiconductor substrate. A drain bit line junction is formed within the active device area of the semiconductor substrate to a first side of the dummy gate structure, and a source bit line junction is formed within the active device area of the semiconductor substrate to a second side of the dummy gate structure. A drain bit line silicide is formed within the drain bit line junction, and a source bit line silicide is formed within the source bit line junction. Furthermore, an interlevel material is formed to surround the dummy gate structure, and the dummy gate structure is then etched away to form a gate opening within the interlevel material. Spacers are then formed at sidewalls of the gate opening within the gate opening. After formation of the spacers, a tunnel dielectric structure is formed at a bottom wall of the gate opening, and a floating gate structure is formed on the tunnel dielectric structure within the gate opening. In addition, a floating dielectric structure is formed on the floating gate structure within the gate opening, and a control gate structure is formed on the floating dielectric structure within the gate opening. In this manner, a self-aligned gate structure is formed to be comprised of the tunnel dielectric structure, the floating gate structure, the floating dielectric structure, and the control gate structure between the spacers within the gate opening.
A method for manufacturing a non-volatile memory. The method comprises steps of forming a first dielectric layer on a substrate and forming a dummy gate layer on the first dielectric layer. Further, the dummy gate layer is defined to form a plurality of dummy gates and a doped region is formed in the substrate by using the dummy gates as a mask. A second dielectric layer is formed on a portion of the first dielectric layer corresponding to the location of the doped region and the dummy gates are removed to expose a portion of the first dielectric layer. A conductive layer is formed over the substrate to cover the second dielectric layer and the first dielectric layer.
A fabrication method for a semiconductor device includes a step of forming a gate insulating film on a semiconductor layer, and a step of forming a first gate electrode layer on the gate insulating film. The fabrication method also includes a step of forming a pocket ion region under the first gate electrode layer, and a step of forming a second gate electrode layer overlaying the first gate electrode layer after forming the pocket ion region.
DRAM cell arrays having a cell area of less than about 4 F.sup.2 comprise an array of vertical transistors with buried bit lines and vertical double gate electrodes. The buried bit lines comprise a silicide material and are provided below a surface of the substrate. The word lines are optionally formed of a silicide material and form the gate electrode of the vertical transistors. The vertical transistor may comprise sequentially formed doped polysilicon layers or doped epitaxial layers. At least one of the buried bit lines is non-orthogonal to at least one of the vertical gate electrodes of the vertical transistors.
