| 摘要 |
PROBLEM TO BE SOLVED: To provide a manufacturing method for a semiconductor memory device, having a tree type capacitor structure capable of widening the memory electrode area, without widening the surface area of the used semiconductor memory device. SOLUTION: A dielectric layer 46 made of, e.g. silicon dioxide, silicon nitride, No or ONO, is formed on the entire exposed surfaces of a trunk-like polysilicon layer 44A and section 38 of a branch-like polysilicon layer. To complete manufacturing of a tree-type capacitor, a polysilicon layer 48 functioning as counter- electrodes to the memory electrodes 44A, 38 is formed on the entire dielectric layer 46. The process of forming the electrode 48 includes a first step of vacuum evaporation to, e.g. a depth of about 1000Å, a 2nd step of diffusing an n-type impurity in the polysilicon layer for raising the conductivity, and etching the polysilicon layer to form the desired oppositely located electrodes 48. |
