US Patent 8012810 Low parasitic capacitance bit line process for stack DRAM

A method of manufacturing low parasitic capacitance bit line for stack DRAM, comprising the following steps: offering a semi-conductor base, which semi-conductor having already included an oxide, plural word line stacks, plural bit line stacks and plural polysilicons; applying a multi layer resist coat; removing the multi layer resist coat and further removing parts of the oxide located on the polysilicon to form contact holes exposing the plural polysilicons; depositing an oxide layer; etching the oxide layer to form the oxide layer spacer; depositing a polysilicon layer; performing lithography and etching on the polysilicon layer thereby allowing the rest of the polysilicon layer that is column-shaped to form capacitor contacts; and using another oxide to fill into the space among the word line stacks and the capacitor contacts.