摘要 |
A dram cell having buried bit line includes a substrate having fin structures thereon, a plurality of deep trenches in the substrate, a buried stripe, a plurality of word lines formed on the substrate and a plurality of capacitors formed on the fin structures. Each of the deep trenches is arranged between two adjacent fin structures. Each of the deep trenches has a metal layer and a poly-silicon layer thereinside to define a buried bit line. The buried stripe is formed in the substrate and next to each of the deep trenches. The bit line is electrically connected to the corresponding fin structure via the buried stripe. The word lines are alternatively arranged with the bit lines, and each of the word lines are disposed cross on the fin structures to construct double gate structures. |