Patent ID: 9704875
Date: 2017-07-11
CPC Classifications: H01L

Claim:
1. A manufacturing method of a semiconductor device provided with a memory cell of a nonvolatile memory, comprising the steps of: (a) preparing a semiconductor substrate; (b) forming a first gate electrode formed on the semiconductor substrate with a first insulating film interposed therebetween, a second gate electrode formed on the semiconductor substrate with a second insulating film having a charge accumulation part therein interposed therebetween, and a third insulating film interposed between the first gate electrode and the second gate electrode, and then forming first source/drain regions in a main surface of the semiconductor substrate so as to sandwich the first gate electrode and the second gate electrode; (c) forming a first silicide layer in contact with each upper surface of the first source/drain regions and a second silicide layer in contact with an upper surface of the second gate electrode; (d) after the step (c), forming a first interlayer insulating film on the semiconductor substrate; (e) polishing the first interlayer insulating film and the second silicide layer to expose upper surfaces of the first gate electrode and the second gate electrode from the first interlayer insulating film and the second silicide layer, thereby forming a third silicide layer in contact with the upper surface of the first gate electrode and a fourth silicide layer in contact with the upper surface of the second electrode; and (f) after the step (e), forming a first metal film on each of the first gate electrode and the second gate electrode, and then carrying out a silicidation process by a heat treatment, thereby forming a fifth silicide layer in contact with the upper surface of the first gate electrode and a sixth silicide layer in contact with the upper surface of the second gate electrode, wherein the first source/drain regions, the first gate electrode, the second gate electrode and the second insulating film constitute the memory cell.