Dynamic random access memory

Abstract

A dynamic random access memory (DRAM) includes a substrate, isolation structures, buried word lines, bit lines, and capacitors. The substrate includes active areas configured into strips and arranged as an array. The isolation structures are disposed in trenches of the substrate. Each isolation structure is disposed between two adjacent active areas. The buried word lines are disposed in parallel in a first direction in the trenches. Each buried word line divides each active area arranged in the same column into a first contact region and a second contact region. The bit lines are disposed in parallel in a second direction on the substrate and across the buried word lines. A longitudinal direction of the active areas is non-orthogonal to the second direction. Each bit line is electrically connected with the first contact regions in the same row. The capacitors are electrically connected with the corresponding second contact regions respectively.