METHOD OF MANUFACTURING SEMICONDUCTOR DEVICE

摘要

An improvement is achieved in the performance of a semiconductor device. In a method of manufacturing the semiconductor device, using a control gate electrode and a memory gate electrode which are formed over a semiconductor substrate as a mask, n-type impurity ions are implanted from a direction perpendicular to a main surface of the semiconductor substrate. Then, using the control gate electrode, the memory gate electrode, and first and second sidewall spacers as a mask, other n-type impurity ions are implanted from a direction inclined relative to the direction perpendicular to the main surface of the semiconductor substrate.

主权项

1. A method of manufacturing a semiconductor device, comprising the steps of:
(a) providing a semiconductor substrate; (b) forming a first gate electrode over a first main surface of the semiconductor substrate via a first gate insulating film; (c) forming a first insulating film having an internal charge storage portion over the first main surface of the semiconductor substrate and a top surface of the first gate electrode; (d) forming a first conductive film over the first insulating film; (e) etching back the first conductive film to leave the first conductive film over a first side surface of the first gate electrode via the first insulating film and thus form a second gate electrode; (f) removing a part of the first insulating film which is uncovered with the second gate electrode to leave the first insulating film between the second gate electrode and the semiconductor substrate and between the first and second gate electrodes; (g) after the step (f), implanting first impurity ions having a first conductivity type into the semiconductor substrate using the first and second gate electrodes as a mask; (h) after the step (g), forming a first sidewall spacer made of a second insulating film over a second side surface of the first gate electrode opposite to the first side surface and forming a second sidewall spacer made of a third insulating film over a third side surface of the second gate electrode opposite to a side surface thereof closer to the first gate electrode; and (i) implanting second impurity ions having the first conductivity type into the semiconductor substrate using the first and second gate electrodes and the first and second sidewall spacers as a mask, wherein, in the step (g), the first impurity ions are implanted from a first direction perpendicular to the first main surface of the semiconductor substrate, and wherein, in the step (i), the second impurity ions are implanted from a second direction inclined relative to the first direction.