Semiconductor integrated circuit device with trench capacitor and method of manufacturing the same
AssigneeKabushiki Kaisha Toshiba
InventorsSoichi Sugiura, Shigeki Sugimoto
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Abstract
A semiconductor integrated circuit device includes a p-silicon substrate, an n-buried layer formed in the substrate to divide the substrate into an upper region and a lower region, a trench formed from the surface of the substrate to the lower region of the substrate through the buried layer, and an electrode formed in the trench. The electrode forms an n-inversion layer using the buried layer as a carrier source, in the lower region of the semiconductor substrate by a field effect. The n-inversion layer constitutes a capacitor together with the electrode.
Claims16
A semiconductor integrated circuit device comprising:
- a semiconductor substrate of a first conductivity type;
- a buried layer of a second conductivity type formed in said semiconductor substrate, said buried layer being spaced apart from a surface of said semiconductor substrate to divide said semiconductor substrate into an upper region and a lower region;
- a trench formed from the surface of said semiconductor substrate to the lower region through said buried layer;
- an electrode formed in said trench, said electrode being capacitively coupled to the lower region;
- a switch connected to said electrode;
- a circuit wiring layer connected to said switch;
- and
- a semiconductor region of the first conductivity type formed at a portion around said trench in the lower region, the first conductivity type of said semiconductor region having a dose lower than a dose of the first conductivity type of the lower region of said semiconductor substrate.
Dependencies are inferred from the claim text.