Semiconductor device with DRAM cell and method of manufacturing the same
AssigneeKabushiki Kaisha Toshiba
InventorsTakeo Furuhata, Takahito Nakajima
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Abstract
A method of manufacturing a semiconductor device includes forming a trench in a semiconductor substrate, isotropically forming a trench surface insulating film on an inner surface of the trench, the trench surface insulating film including a deep part functioning as a capacitor insulating film, forming a surface layer side insulating film on the inner surface of the trench so that the surface layer side insulating film is continuously rendered thinner from the surface side of the substrate toward the deep side of the trench, and forming an electrode layer inside the surface layer side insulating film and the trench surface insulating film both formed on the inner surface of the trench.
Claims6
A method of manufacturing a semiconductor device, comprising:
- forming a trench in a semiconductor substrate;
- isotropically forming a trench surface insulating film on an inner surface of the trench, the trench surface insulating film including a deep portion functioning as a capacitor insulating film;
- forming a surface layer side insulating film on the inner surface of the trench so that the surface layer side insulating film is continuously rendered thinner from the surface side of the substrate toward the deep portion side of the trench;
- and
- forming an electrode layer inside the surface layer side insulating film and the trench surface insulating film both formed on the inner surface of the trench.
A semiconductor device comprising:
- a semiconductor substrate;
- a trench formed in the substrate;
- an insulating film formed on an inner surface of the trench so as to be rendered thicker from a substrate surface side thereof toward a trench deep side thereof;
- and
- an electrode layer formed inside the insulating film formed inside the trench so as to extend from a trench deep part side toward the surface side of the substrate,
- wherein the substrate surface side of the insulating film functions as a collar insulating film retaining an insulation performance between the electrode layer and the semiconductor substrate, and the trench deep side of the insulating film functions as a capacitor insulating film composing a capacitor of a DRAM cell.
Dependencies are inferred from the claim text.