Variable capactor structure and method of manufacture
AssigneeUnited Microelectronics Corp.
InventorsJing-Horng Gau, Anchor Chen
Life of this patent
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Abstract
A variable capacitor comprising a substrate having a first type ion-doped buried layer, a first type ion-doped well, a second type ion-doped region and a conductive layer thereon. The first type ion-doped well is formed within the substrate. The first type ion-doped well has a cavity. The first type ion-doped buried layer is in the substrate underneath the first type ion-doped well. The first type ion-doped buried layer and the first type ion-doped well are connected. The second type ion-doped region is at the bottom of the cavity of the first type ion-doped well. The conductive layer is above and in connection with the first type ion-doped buried layer.
Claims27
A variable capacitor structure, comprising:
- a substrate;
- a first type ion-doped well within the substrate, wherein the first type ion-doped well has a cavity;
- a first-type ion-doped buried layer in the substrate underneath the first type ion-doped well, wherein the first type ion-doped buried layer and the first type ion-doped well are connected;
- a second type ion-doped region at the bottom of the cavity of the first type ion-doped well;
- and
- a conductive layer over the first type ion-doped buried layer, wherein the conductive layer and the first type ion-doped buried layer are connected.
A variable capacitor structure, comprising:
- a substrate;
- a first type ion-doped well within the substrate, wherein the first type ion-doped region has a shallow trench isolation structure;
- a first type ion-doped buried layer in the substrate underneath the first type ion-doped well, wherein the first type ion-doped buried layer and the first type ion-doped well are connected;
- at least one second type ion-doped region in the first type ion-doped well at the bottom of the shallow trench isolation structure;
- and
- at least one first conductive layer connected to the first type ion-doped buried layer.
A method of forming a variable capacitor, comprising the steps of:
- providing a substrate having a first type ion-doped buried layer and a first type ion-doped well, wherein the first type ion-doped buried layer is above and in connection to the first type ion-doped well;
- forming a conductive layer in the substrate above the first type ion-doped buried layer;
- removing a portion of the first type ion-doped well to form at least one first opening without exposing the first type ion-doped buried layer;
- and
- forming a second type ion-doped region in the first type ion-doped well at the bottom of the first opening.
A method of forming a variable capacitor, comprising the steps of:
- providing a substrate having a first type ion-doped buried layer and a first type ion-doped well, wherein the first type ion-doped buried layer is above and in connection to the first type ion-doped well;
- forming a shallow trench isolation structure in the first type ion-doped well;
- removing a portion of the first type ion-doped well to form an opening that exposes the first type ion-doped buried layer;
- forming a dielectric layer over the substrate;
- forming at least one first contact opening and at least one second contact opening in the dielectric layer, wherein the first contact opening exposes a portion of the metal suicide layer and the second contact opening exposes the first type ion-doped well at the bottom of the shallow trench isolation structure;
- forming a second type ion-doped region in the first type ion-doped region at the bottom of the shallow trench isolation structure;
- and
- forming a contact inside the first contact opening and the second contact opening.
Dependencies are inferred from the claim text.