Method of producing semiconductor device with viscous flow of silicon oxide

摘要

There is disclosed a method of producing a semiconductor memory device. An interlayer insulation film is formed on a semiconductor substrate including a switching transistor. Then, a memory node pattern reaching an active region of the switching transistor is formed. A cell plate electrode pattern is formed through an insulation film formed on the memory node in such a manner that a value obtained by subtracting a thickness of a polycrystalline silicon film for a cell plate electrode from an overlapping dimension of a memory node pattern and the cell plate electrode pattern is not less than two times larger and not more than ten times larger than a thickness of deposition of a BPSG film. Then, the BPSG film is deposited on an entire surface, and then is caused to viscously flow by a heat treatment. Then, an aluminum wiring is formed on the BPSG film. With this construction, a step of the aluminum wiring in a boundary region between a memory cell array portion and a peripheral circuit portion, or in a word line-backing contact forming region, is decreased, thereby preventing the lowering of the yield of the aluminum wiring which is caused by the cutting of the aluminum wiring and the remaining of a residue of etching for a contact-forming electrode (for example, tungsten).