Capacitor structure
AssigneeIpdia
InventorsFrédéric Voiron, Jean-René Tenailleau
Life of this patent
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Abstract
The invention relates to a capacitor structure (2) comprising a silicon substrate (4) with first and second sides (6, 8), a double double Metal Insulator Metal trench capacitor (10) including a basis electrode (12), an insulator layer (16, 20), a second and a third conductive layers (18, 22); and comprising a second pad (26) and a fourth pad (30) coupled to the basis electrode (12), a first pad (24) and a third pad (28) coupled together, the first pad (24) being located on the same substrate side than the second pad (26), the third pad (28) being located on the same substrate side than the fourth pad (30), the third pad (28) being coupled to the second conductive layer (18), said second conductive layer (18) being flush with or protruding from the opposite second side (8).
Claims16
A capacitor structure comprising:
- a silicon substrate with a first side and an opposite second side parallel to the first side,
- a trench etched in the semiconductor substrate from the first side,
- a double Metal Insulator Metal trench capacitor including along at least one stacking direction which is parallel to both the first side and the opposite second side of the silicon substrate:
- a basis electrode forming a first conductive layer sunk in the trench and coupled to the substrate,
- a first insulator layer stacked on the basis electrode in the trench,
- a second conductive layer stacked on the first insulator layer in the trench,
- a second insulator layer stacked on the second conductive layer in the trench, and
- a third conductive layer stacked on the second insulator layer in the trench and coupled to the basis electrode,
- wherein a second pad and a fourth pad are coupled to the basis electrode, wherein the second pad is located on the first side of the silicon substrate and the fourth pad is located on the opposite second side of the silicon substrate, and
- in that a first pad and a third pad are coupled together and insulated from the silicon substrate and from the second pad and the fourth pad, the first pad being located on the first side of the silicon substrate, the third pad being located on the opposite second side of the silicon substrate, the third pad being coupled to the second conductive layer, and said second conductive layer being flush with or protruding from said opposite second side of the silicon substrate.
A method for manufacturing a capacitor structure comprising the steps of:
- providing a silicon substrate having a first side and an opposite second side parallel to the first side,
- forming a trench in the silicon substrate from the first side,
- forming a basis electrode in the trench, and coupled to the substrate,
- forming a double Metal Insulating Metal trench capacitor by stacking in the trench along at least one stacking direction which is parallel to both the first side and the opposite second side of the silicon substrate:
- a first insulating layer on the basis electrode which forms a first conductive layer,
- a second conductive layer on the first insulating layer,
- a second insulating layer on the second conductive layer,
- a third conductive layer on the second insulating layer,
- etching the opposite second side of the silicon substrate until the first insulating layer,
- etching the first insulating layer,
- depositing a thick dielectric layer on the opposite second side,
- processing a first pad in connection with the second conductive layer and a second pad in connection with the silicon substrate and the third conductive layer, the first pad and the second pad being placed on the first side, and
- processing a third pad in connection with the second conductive layer and a fourth pad in connection with the silicon substrate, the third pad and the fourth pad being placed on the opposite second side.
Dependencies are inferred from the claim text.