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US 12,550,400 B2Granted
Manufacturing method of semiconductor device
AssigneeRenesas Electronics Corporation
InventorKouichi Konishi
Life of this patent
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Abstract
Increasing in a contact-resistance between a trench gate lead-out electrode and a gate lead-out contact member is suppressed. It is assumed that a natural oxidation film is formed in the polysilicon film when the trench gate lead-out electrode is formed. In case of the natural oxidation film is formed, a desired etching process is performed so that the natural oxidation film does not protrude beyond the upper surface of the trench gate lead-out electrode.
Claims13
A manufacturing method of a semiconductor device, the manufacturing method comprising the steps of:
- (a) forming a first trench having a first width and a second trench having a second width greater than the first width on a semiconductor substrate having a first main surface and a second main surface opposite to the first main surface;
- (b) forming a first trench electrode and a second trench electrode by sequentially laminating a first conductive film and a second conductive film to fill the first trench and the second trench, respectively;
- (c) forming an interlayer insulating film on the first main surface;
- (d) forming a first contact opening penetrating through the interlayer insulating film and exposing an upper surface of the first trench electrode and the first main surface, and forming a second contact opening penetrating through the interlayer insulating film and exposing an upper surface of the second trench electrode;
- (e) etching the upper surface of the first trench electrode and the first main surface exposed from the first contact opening, and the upper surface of the second trench electrode exposed from the second contact opening, respectively;
- and
- (f) filling a contact member in the first contact opening and the second contact opening, wherein
- the step of (e) includes:
- (e1) retreating the upper surface of the first trench electrode and the first main surface exposed from the first contact opening, and the upper surface of the second trench electrode exposed from the second contact opening, in a thickness direction of the semiconductor substrate respectively;
- and
- (e2) after the step of (e1), removing residue left inside the first contact opening and the second contact opening.
8 more elements
Dependencies are inferred from the claim text.