Semiconductor device and its manufacturing method
AssigneeRenesas Electronics Corporation
InventorKazuki YOKOTA
Life of this patent
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Abstract
In an element isolation region defining an element formation region, there is formed an element isolation unit including an element isolation unit and the other element isolation unit. The other element isolation unit is arranged in a direction intersecting a direction in which the element isolation unit extends from the element isolation unit. The element isolation unit includes a sidewall oxide film formed in a trench, a titanium film, a titanium nitride film, and a tungsten film. The tungsten film is formed to cover the bottom surface of a trench in the element isolation unit and to close an opening end of a trench in the other element isolation unit. A plug is formed in contact with the tungsten film of the element isolation unit.
Claims11
A semiconductor device comprising:
- a semiconductor substrate;
- an element isolation unit which is formed in the semiconductor substrate;
- an element formation region which is defined by the element isolation unit;
- an insulating film which is formed to cover the element formation region;
- and
- a contact unit which penetrates through the insulating film and is formed in contact with the element isolation unit,
- wherein the element isolation unit includes
- a first element isolation unit which reaches a first depth from a surface of the semiconductor substrate and has a first width, and
- a second element isolation unit which reaches the first depth from the surface of the semiconductor substrate and has a second width narrower than the first width,
- wherein the first element isolation unit includes a first conductor unit which is electrically coupled to the semiconductor substrate at a lower end of the first element isolation unit,
- wherein the second element isolation unit includes a second conductor unit in contact with the first conductor unit, and
- wherein the contact unit is in contact with the second conductor unit.
A method of manufacturing a semiconductor device, comprising the steps of:
- forming trenches which include a first trench reaching a first depth from a surface of a semiconductor substrate and having a first width and a second trench having a second width narrower than the first width;
- forming a sidewall insulating film covering a sidewall surface of each of the first trench and the second trench and for exposing a part the semiconductor substrate positioned on a bottom surface of each of the first trench and the second trench;
- forming a conductive film through the intervening sidewall insulating film in the first trench and the second trench;
- forming a first conductor unit through the intervening sidewall insulating film in the first trench, and forming a second conductor unit through the intervening sidewall insulating film in the second trench, by performing an etch back process for the conductive film and removing a part of the conductive film positioned above an upper surface of the semiconductor substrate while remaining a part of the conductive film positioned in each of the first trench and the second trench;
- forming an insulating film to cover the first conductor unit and the second conductor unit;
- forming a contact hole for exposing the second conductor unit in the insulating film, and
- forming a contact unit in contact with the second conductor unit in the contact hole.
Dependencies are inferred from the claim text.