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US 2019/0198681 A1Published application
Semiconductor device and method of manufacturing the same
AssigneeRenesas Electronics Corporation
InventorTomohiro HAYASHI
Life of this patent
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Abstract
In a split-gate MONOS memory including a FINFET, occurrence of erroneous write in an unselected cell due to electric field concentration at an upper end of a fin is prevented, and thus reliability of a semiconductor device is improved. An insulating film is formed between an upper surface of a fin and each of a control gate electrode and a memory gate electrode in a memory cell region, so that in a gate insulating film of each of a control transistor and a memory transistor, thickness of a portion on the fin is larger than thickness of a portion covering side surfaces of the fin. The insulating film having a bird's beak at its end portion is formed to round a corner of the fin.
Claims18
A semiconductor device, comprising:
- a semiconductor substrate;
- a first protrusion that is a part of the semiconductor substrate, protrudes from an upper surface of a first region of the semiconductor substrate, and extends in a first direction along the upper surface of the semiconductor substrate;
- and
- a first gate electrode that covers an upper surface and side surfaces of the first protrusion via a first gate insulating film, and extends along the upper surface of the semiconductor substrate and in a second direction orthogonal to the first direction;
- wherein the first gate insulating film includes:
- a first insulating film formed between the upper surface of the first protrusion and the first gate electrode, and exposing the side surfaces of the first protrusion, and
- a second insulating film that covers the side surfaces of the first protrusion and the first insulating film,
- wherein the first gate electrode configures a nonvolatile memory element, and
- wherein a second thickness of an end portion in the second direction of the first insulating film is larger than a first thickness of a central portion in the second direction of the first insulating film.
6 more elements
A semiconductor device, comprising:
- a semiconductor substrate;
- a first protrusion that is a part of the semiconductor substrate, protrudes upward from an upper surface of a first region of the semiconductor substrate, and extends in a first direction along the upper surface of the semiconductor substrate;
- a first gate electrode that covers an upper surface and side surfaces of the first protrusion with a first gate insulating film in between, and extends along the upper surface of the semiconductor substrate and in a second direction orthogonal to the first direction;
- a first gate insulating film formed between the first protrusion and the first gate electrode, and covering the upper surface of the first protrusion and the side surfaces of the first protrusion;
- a second gate electrode that covers the upper surface and the side surfaces of the first protrusion with a second gate insulating film including a charge storage part in between, and extends in the second direction alongside the first gate electrode;
- and
- first source-drain regions formed in the upper surface of the first protrusion,
- wherein the first gate electrode, the second gate electrode, and the first source-drain regions configure a nonvolatile memory element, and
- wherein thickness of the first gate insulating film covering the upper surface of the first protrusion is larger than thickness of the first gate insulating film covering the side surfaces of the first protrusion.
6 more elements
A method of manufacturing a semiconductor device, the method comprising the steps of:
- (a) providing a semiconductor substrate;
- (b) forming a first trench in an upper surface of the semiconductor substrate to form a first protrusion that is a part of the semiconductor substrate, protrudes from the upper surface of the semiconductor substrate, and extends in a first direction along the upper surface of the semiconductor substrate;
- (c) forming a fourth insulating film covering side surfaces of the first protrusion;
- (d) after the step (c), oxidizing the first protrusion exposed from the fourth insulating film to form a first insulating film covering the upper surface of the first protrusion;
- (e) after the step (d), removing the fourth insulating film;
- (f) after the step (e), forming a first gate electrode that covers the upper surface and the side surfaces of the first protrusion with a first gate insulating film in between and extends in the second direction, the first gate insulating film including a second insulating film and the first insulating film, the second insulating film having a smaller thickness than the first insulating film and covering the side surfaces of the first protrusion in a second direction orthogonal to the first direction;
- (g) forming a second gate electrode that covers the upper surface and the side surfaces of the first protrusion with a second gate insulating film including a charge storage part in between, and extends in the second direction alongside the first gate electrode;
- (h) removing the first insulating film exposed from the first gate electrode;
- and
- (i) forming first source-drain regions in the upper surface of the first protrusion;
- wherein the first gate electrode, the second gate electrode, and the first source-drain regions configure a nonvolatile memory element.
8 more elements
Dependencies are inferred from the claim text.