Semiconductor device and manufacturing method thereof
AssigneeWinbond Electronics Corp.
InventorNoriaki Ikeda
Life of this patent
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Abstract
A semiconductor device and a manufacturing method thereof are provided. The semiconductor device includes a semiconductor substrate, word lines and bit lines. The semiconductor substrate has active regions separated from one another and extending along a first direction. The word lines are formed in the semiconductor substrate. The active regions are respectively intersected with one or more of the word lines. The word lines respectively have thick portions and a narrow portion continuously extending on the thick portions along a second direction. The thick portions are located at where the word lines are intersected with the active regions. The bit lines are formed over the semiconductor substrate, and extending along a third direction intersected with the first and second directions.
Claims20
A semiconductor device, comprising:
- a semiconductor substrate, having active regions separated from one another and extending along a first direction;
- word lines, formed in the semiconductor substrate, wherein the active regions are respectively intersected with one or more of the word lines, the word lines respectively have separate thick portions and a narrow portion continuously extending on the thick portions along a second direction, and the thick portions are located at where the word lines are intersected with the active regions;
- and
- bit lines, formed over the semiconductor substrate and extending along a third direction intersected with the first and second directions.
A manufacturing method of a semiconductor device, comprising:
- providing a semiconductor substrate with active regions and a trench isolation structure, wherein the active regions extend along a first direction, and the trench isolation structure spreads between the active regions;
- forming initial gate trenches at a top surface of the semiconductor substrate, wherein the initial gate trenches extend through the active regions and the trench isolation structure along a second direction intersected with the first direction;
- forming insulating lining layers on sidewalls of the initial gate trenches;
- further extending the initial gate trenches downwardly into the semiconductor substrate by an etching process using the insulating lining layers as masks, so as to form gate trenches;
- performing a first oxidation process to oxidize exposed surfaces of portions of the gate trenches within the active regions, so as to form sacrificial layers;
- removing the insulating lining layers and the sacrificial layers;
- and
- filling a conductive material into the gate trenches, in order to form word lines.
Dependencies are inferred from the claim text.