Patent ID: 8372718
Filing Date: 2013-02-12
Classification: H01L

Abstract:
1. A method of manufacturing a semiconductor device which has a first MISFET and a second MISFET, comprising steps of: (a) forming a first gate insulating film of the first MISFET over a first region of a semiconductor substrate; (b) forming a second gate insulating film of the second MISFET over a second region of the semiconductor substrate; (c) forming a first conductive film over the first and second gate insulating films; (d) after the step (c), patterning the first conductive film in order to be kept on the first and second gate insulating films, respectively; (e) after the step (d), forming a plurality of grooves in the first and second regions of the semiconductor substrate by using the first conductive films as a mask; (f) after the step (e), forming a plurality of element isolations in the grooves by embedding insulating films in the grooves; (g) after the step (f), forming a second conductive film over the first conductive film of the first region, the first conductive film of the second region, element isolations of the first region and element isolations of the second region; (h) after the step (g), patterning the second conductive film of the first region in order to be kept on the first conductive film of the first region; and (i) after the step (g), patterning the second conductive film of the second region and the first conductive film of the second region, wherein the first and second conductive films of the first region constitute a gate electrode of the first MISFET, wherein the first and second conductive films of the second region constitute a gate electrode of the second MISFET, wherein a thickness of the first gate insulating film is larger than a thickness of the second gate insulating film, wherein, in a gate length direction of the first MISFET, both edges of the second conductive film of the first region are arranged over the element isolations of the first region, and wherein, in a gate length direction of the second MISFET, both edges of the first and second conductive films of the second region are arranged over the semiconductor substrate.