Semiconductor device and a manufacturing method thereof
AssigneeRenesas Electronics Corporation
InventorAtsushi AMO
Life of this patent
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Abstract
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.
Claims18
1-16. (canceled)
A method for manufacturing a semiconductor device, comprising:
- (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) embedding a third insulation film in the first trench;
- (d) after (c), forming a first conductor film over the main surface of the semiconductor substrate in the first region and the second region;
- (e) processing the first conductor film, and thereby forming a control gate electrode formed of the first conductor film over the main surface of the semiconductor substrate in the first region, and removing the first conductor film, and exposing the third insulation film in the second region;
- (f) removing at least a portion of the third insulation film in the first trench;
- (g) after (f), sequentially stacking a second insulation film having a charge accumulation part in the inside thereof, and a second conductor film over the semiconductor substrate, and thereby embedding the second insulation film and the second conductor film in the first trench;
- (h) processing the second insulation film and the second conductor film, and thereby forming a memory gate electrode formed of the second conductor film at the sidewall of the control gate electrode via the second insulation film in the first region, and forming a first electrode formed of the second insulation film in the second region;
- and
- (i) after (h), 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, the semiconductor substrate under the first electrode form a capacitor element.
18-20. (canceled)
Dependencies are inferred from the claim text.