Method of manufacturing semiconductor device
AssigneeRenesas Electronics Corporation
InventorsYu Nagahama, Yuya Abiko
Life of this patent
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Abstract
A trench is formed in a semiconductor substrate. A first silicon oxide film is formed in an inside of the trench. A poly-crystalline silicon film is formed on the first silicon oxide film. A second silicon oxide film is formed from the poly-crystalline silicon film by performing a thermal oxidation treatment to the poly-crystalline silicon film. Thus, an insulating film including the first silicon oxide film and the second silicon oxide film is formed. A first conductive film is formed so as to embed the inside of the trench via the insulating film.
Claims17
A method of manufacturing a semiconductor device, comprising steps of:
- (a) providing a semiconductor substrate of a first conductivity type, the semiconductor substrate having an upper surface and a lower surface;
- (b) forming a trench in the semiconductor substrate at the upper surface of the semiconductor substrate;
- (c) forming a first silicon oxide film in an inside of the trench;
- (d) forming a poly-crystalline silicon film on the first silicon oxide film;
- (e) by performing a thermal oxidation treatment to the poly-crystalline silicon film and thereby forming a second silicon oxide film from the poly-crystalline silicon film, forming a first insulating film including the first silicon oxide film and the second silicon oxide film;
- and
- (f) forming a first conductive film so as to embed the inside of the trench via the first insulating film,
- wherein a thickness of the second silicon oxide film is greater than a thickness of the first silicon oxide film.
A method of manufacturing a semiconductor device, comprising steps of:
- (a) providing a semiconductor substrate of a first conductivity type, the semiconductor substrate having an upper surface and a lower surface;
- (b) forming a trench in the semiconductor substrate at the upper surface of the semiconductor substrate;
- (c) forming a first silicon oxide film in an inside of the trench;
- (d) forming a poly-crystalline silicon film on the first silicon oxide film;
- (e) by performing a thermal oxidation treatment to the poly-crystalline silicon film and thereby forming a second silicon oxide film from the poly-crystalline silicon film, forming a first insulating film including the first silicon oxide film and the second silicon oxide film;
- and
- (f) forming a first conductive film so as to embed the inside of the trench via the first insulating film,
- wherein, in the step of (d), the poly-crystalline silicon film is formed not only on the first silicon oxide film but also on the lower surface of the semiconductor substrate,
- (n) after the step of (d) and before the step of (e), removing the poly-crystalline silicon film formed on the lower surface of the semiconductor substrate.
A method of manufacturing a semiconductor device, comprising steps of:
- (a) providing a semiconductor substrate of a first conductivity type, the semiconductor substrate having an upper surface and a lower surface;
- (b) forming a trench in the semiconductor substrate at the upper surface of the semiconductor substrate;
- (c) forming a first silicon oxide film in an inside of the trench;
- (d) forming a poly-crystalline silicon film on the first silicon oxide film;
- (e) by performing a thermal oxidation treatment to the poly-crystalline silicon film and thereby forming a second silicon oxide film from the poly-crystalline silicon film, forming a first insulating film including the first silicon oxide film and the second silicon oxide film;
- and
- (f) forming a first conductive film so as to embed the inside of the trench via the first insulating film,
- wherein the step of (f) includes steps of:
- (f1) after the step of (e), in the inside of the trench, forming a second conductive film on the first insulating film;
- (f2) after the step of (f1), reducing a thickness of the second conductive film by performing an anisotropic etching treatment to the second conductive film;
- and
- (f3) after the step of (f2), forming a third conductive film so as to embed the inside of the trench, and
- wherein the first conductive film includes the second conductive film and the third conductive film.
Dependencies are inferred from the claim text.