| 摘要 |
PURPOSE: A method for manufacturing a semiconductor memory device is to delete a plug contact process connecting a capacitor with a cell transistor and decrease difficulty in a subsequent multi-layer interconnection line process. CONSTITUTION: A field oxide(110) is formed at an isolation region of an upper substrate(104) of a silicon on insulator(SOI) substrate. A cell transistor having a gate electrode(120) and a source/drain region(126) is formed on the SOI substrate. The first interlayer dielectric is formed on the entire surface of the resultant SOI substrate. The resultant SOI substrate is etched to form a contact hole extending from the first interlayer dielectric to a lower substrate(100) of the SOI substrate. A thin insulating film(132) is formed on the contact hole. The first conductive film(134) is filled in the contact hole. The first conductive film and the underlying thin insulating film are etched below the source/drain region of the cell transistor. The second conductive film(136) is filled in the contact hole and then polished to form the lower electrode comprised of the first and second conductive films. The second interlayer dielectric(138) is formed on the resultant substrate. The second interlayer dielectric and the underlying first interlayer dielectric are etched to form a contact hole. A conductive film is deposited to fill the contact hole and is then patterned to form a bit line(140).
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