Trench capacitor and method for manufacturing the same
AssigneeInfineon Technologies AG
InventorsMatthias Goldbach, Thomas Hecht, Jörn Lützen, Bernhard Sell
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Abstract
A trench capacitor has a first capacitor electrode, a second capacitor electrode, and a dielectric, which is arranged between the capacitor electrodes. The first capacitor electrode has a tube-like structure, which extends into a substrate. The second capacitor electrode includes a first section which is opposite to the internal side of the tube-like structure, with the dielectric arranged therebetween, and a second section, which is opposite to the external side of the tube-like structure with the dielectric arranged therebetween.
Claims16
Trench capacitor, comprising:
- a first capacitor electrode;
- a second capacitor electrode;
- and
- a dielectric arranged between the capacitor electrodes,
- wherein the first capacitor electrode comprises a tube-like structure extending into a substrate, and
- wherein the second capacitor electrode comprises a first section, which is opposite to the internal side of the tube-like structure, with the dielectric arranged therebetween, and which comprises a second section, which is opposite to the external side of the tube-like structure, with the dielectric arranged therebetween,
- wherein areas of the first section of the second capacitor electrode and of the internal side of the tube-like structure, which are positioned opposite to each other, extend into a region, in which a collar oxide is formed, which comprises a greater thickness than the dielectric, which is arranged between the second section of the second capacitor electrode and the external side of the tube-like structure.
Method for manufacturing a trench capacitor, comprising the steps of:
- generating a trench in a substrate of a first doping type, wherein a section of a second doping type adjoins a portion of the trench;
- subsequently generating a first dielectric layer at least on side walls of the trench;
- subsequently generating a conductive layer on the first dielectric layer opposite to the section of the second doping type;
- subsequently generating a second dielectric layer on the conductive layer;
- and
- subsequently generating conductive areas on the second dielectric layer, which are opposite to the conductive layer with the second dielectric arranged therebetween and which are electrically conductively connected to the section of a second doping type.
Dependencies are inferred from the claim text.