SEMICONDUCTOR DEVICE AND A MANUFACTURING METHOD THEREOF

摘要

In a semiconductor device including a split gate type MONOS memory, and a trench capacitor element having an upper electrode partially embedded in trenches formed in the main surface of a semiconductor substrate, merged therein, the flatness of the top surface of the upper electrode embedded in the trench is improved. The polysilicon film formed over the semiconductor substrate to form a control gate electrode forming a memory cell of the MONOS memory is embedded in the trenches formed in the main surface of the semiconductor substrate in a capacitor element formation region, thereby to form the upper electrode including the polysilicon film in the trenches.

主权项

1. A method for manufacturing a semiconductor device, comprising the steps of:
(a) providing a semiconductor substrate having a first region and a second region arranged along a main surface; (b) forming a first trench in the main surface of the semiconductor substrate in the second region; (c) covering the sidewall and the bottom surface of the first trench with a first insulation film; (d) after the step (c), forming a first conductor film over the main surface of the semiconductor substrate in the first region and the second region, and thereby embedding the first conductor film in the first trench via the first insulation film; (e) processing the first conductor film in the first region, and thereby forming a control gate electrode formed of the first conductor film; (f) forming a memory gate electrode at the sidewall of the control gate electrode via a second insulation film having a charge accumulation part in the inside thereof; (g) processing the first conductor film, and thereby forming a first electrode formed of the first conductor film filling the first trench in the second region; and (h) after the step (f), forming a pair of first source/drain regions in the main surface of the semiconductor substrate in the first region, wherein the control gate electrode, the memory gate electrode, and the pair of first source/drain regions form a memory cell of a nonvolatile memory, and wherein the first electrode and the semiconductor substrate under the first electrode form a capacitor element.