Patent ID: 6303478
Filing Date: 2001-10-16
Classification: H01L

Abstract:
A method for fabricating a semiconductor integrated circuit device, which at least includes a memory cell array part and a peripheral circuit part, comprising the steps of:forming a first interlayer insulating film on a semiconductor substrate;removing selectively a predetermined portion of said first interlayer insulating film and forming a first connection hole the sides of which are substantially vertical to the bottom thereof, the first connection hole penetrating said first interlayer insulating film;padding said first connection hole with a metallic film to form a first plug;forming a second interlayer insulating film on said first interlayer insulating film;removing selectively a predetermined portion of said second interlayer insulating film and forming a second connection hole the sides of which are substantially vertical to the bottom thereof, the second connection hole penetrating said second interlayer insulating film; andpadding said second connection hole with a metallic film and forming a second plug directly connected with said first plug,wherein each of said first and second interlayer insulating films has an upper surface that is substantially flat over areas, at a principal plane of the substrate, where said memory cell array part and said peripheral circuit part are located, and a height of the upper surface of each of said first and second interlayer insulating films, measured as a vertical distance away from the principal plane of the substrate, is substantially equal at locations of said memory cell array part and said peripheral circuit part, andwherein over an area where said memory cell array part is located a plug formed thereat has a vertical length substantially the same as a thickness of an interlayer insulating film corresponding thereto, and over an area where said peripheral circuit part is located a plug formed thereat has a vertical length that is less than the thickness of an interlayer insulating film corresponding thereto.