Integrated circuits with capacitors and methods for producing the same
Integrated circuits and methods of producing the same are provided. In an exemplary embodiment, an integrated circuit includes a substrate with an active layer overlying a buried insulator layer that in turn overlies a handle layer, where the active layer includes a first active well. A first source, a first drain, and a first channel are defined within the first active well, where the first channel is between the first source and the first drain. A first gate dielectric directly overlies the first channel, and a first gate directly overlies the first gate dielectric, where a first capacitor includes the first source, the first drain, the first channel, the first gate dielectric, and the first gate. A first handle well is defined within the handle layer directly underlying the first channel and the buried insulator layer.
1. An integrated circuit comprising:
a substrate comprising an active layer overlying a buried insulator layer that in turn overlies a handle layer, wherein the active layer comprises a first active well;
a first source defined within the first active well;
a first drain defined within the first active well;
a first channel defined within the first active well between the first source and the first drain;
a first gate dielectric directly overlying the first channel;
a first gate directly overlying the first gate dielectric, wherein a first capacitor comprises the first source, the first drain, the first channel, the first gate dielectric, and the first gate; and
a first handle well defined in the handle layer, wherein the first handle well directly underlies the first channel and the buried insulator layer.
2. The integrated circuit of claim 1 further comprising:
a contact in electrical communication with the first handle well.
3. The integrated circuit of claim 1 further comprising:
a second capacitor, wherein the first capacitor and the second capacitor are electrically connected in parallel.
4. The integrated circuit of claim 3 wherein the active layer further comprises a second active well, and wherein the second capacitor comprises:
a second source defined within the second active well;
a second drain defined within the second active well;
a second channel defined within the second active well between the second source and the second drain;
a second gate dielectric directly overlying the second channel; and
a second gate directly overlying the second gate dielectric.
5. The integrated circuit of claim 4 further comprising:
a second handle well defined in the handle layer directly underlying the second channel and the buried insulator layer.
6. The integrated circuit of claim 4 wherein one of the first capacitor and the second capacitor is an N capacitor and wherein the other of the first capacitor and the second capacitor is a P capacitor.
7. The integrated circuit of claim 4 wherein:
the first capacitor comprises a first capacitance/voltage curve with a first inflection point, wherein the first capacitance/voltage curve has a first inflection point voltage and a first inflection point capacitance at the first inflection point, wherein a first capacitance is measured at a first applied voltage greater than the first inflection point voltage, and wherein the first capacitance is greater than the first inflection point capacitance;
the second capacitor comprises a second capacitance/voltage curve with a second inflection point, wherein the second capacitance/voltage curve has a second inflection point voltage and a second inflection point capacitance at the second inflection point, wherein a second capacitance is measured at a second applied voltage that is greater than the second inflection point voltage, and wherein the second capacitance is less than the second inflection point capacitance; and
wherein the first capacitor and the second capacitor produce a combined capacitance/voltage curve.
8. The integrated circuit of claim 4 wherein:
the first capacitor and the second capacitor are electrically connected to produce a combined capacitance/voltage curve.
9. The integrated circuit of claim 8 wherein:
the first handle well is configured to modify a first capacitance/voltage curve when voltage is applied to the first handle well, and wherein modification of the first capacitance/voltage curve modifies the combined capacitance/voltage curve.
10. The integrated circuit of claim 8 wherein:
the first source, the first drain, and the second gate are in electrical communication; and
the second source, the second drain, and the first gate are in electrical communication.
11. The integrated circuit of claim 8 wherein:
the first source, the second source, the first drain, and the second drain are in electrical communication; and
the first gate and the second gate are in electrical communication.
12. The integrated circuit of claim 1 wherein the first channel and the first handle well comprise the same type of conductivity determining impurity.
13. An integrated circuit comprising:
a first capacitor overlying a buried insulator layer that in turn overlies a first handle well such that the first capacitor directly overlies the first handle well, wherein the first capacitor comprises a first capacitance/voltage curve;
a second capacitor, wherein the second capacitor comprises a second capacitance/voltage curve;
a capacitor interconnect electrically connecting the first capacitor and the second capacitor to produce a combined capacitance/voltage curve, wherein a voltage applied to the first handle well changes the combined capacitance/voltage curve.
14. The integrated circuit of claim 13 where:
the first capacitor comprises a first source, a first drain, and a first channel positioned between the first source and the first drain, and wherein the first channel and the first handle well comprise conductivity determining impurities of the same type.
15. The integrated circuit of claim 13 further comprising:
a second handle well underlying the second capacitor, wherein the buried insulator layer is positioned between the second handle well and the second capacitor, wherein the second capacitor comprises a second source, a second drain, and a second channel positioned between the second source and the second drain, wherein the second channel and the second handle well comprises conductivity determining impurities of the same type.
16. The integrated circuit of claim 13 wherein:
the first capacitance/voltage curve has a first inflection point, wherein the first capacitance/voltage curve has a first inflection point voltage and a first inflection point capacitance at the first inflection point, wherein a first capacitance is measured at a first applied voltage greater than the first inflection point voltage, and wherein the first capacitance is greater than the first inflection point capacitance; and
the second capacitor comprises a second capacitance/voltage curve with a second inflection point, wherein the second capacitance/voltage curve has a second inflection point voltage and a second inflection point capacitance at the second inflection point, wherein a second capacitance is measured at a second applied voltage that is greater than the second inflection point voltage, and wherein the second capacitance is less than the second inflection point capacitance.
17. A method of producing an integrated circuit comprising:
forming a first active well in an active layer of a substrate, wherein the active layer overlies a buried insulator layer that in turn overlies a handle layer;
forming a first handle well in the handle layer underlying the first active well, wherein the first active well and the first handle well comprise a conductivity determining impurity of the same type;
forming a first source within the first active well;
forming a first drain within the first active well such that a first channel is defined within the first active well between the first source and the first drain;
forming a first gate dielectric overlying the first channel;
forming a first gate overlying the first gate dielectric, wherein a first capacitor comprises the first source, the first drain, the first channel, the first gate dielectric, and the first gate; and
forming a contact in electrical communication with the first handle well.
18. The method of claim 17 further comprising:
forming a second active well in the active layer of the substrate;
forming a second handle well in the handle layer underlying the second active well, wherein the second active well and the second handle well comprise conductivity determining impurities of the same type;
forming a second source within the second active well;
forming a second drain within the second active well such that a second channel is defined within the second active well between the second source and the second drain;
forming a second gate dielectric overlying the second channel; and
forming a second gate overlying the second gate dielectric, wherein a second capacitor comprises the second source, the second drain, the second channel, the second gate dielectric, and the second gate.
19. The method of claim 18 further comprising:
forming a capacitor interconnect that electrically connects the first capacitor and the second capacitor to produce a combined capacitance/voltage curve.
20. the method of claim 19 further comprising:
applying a voltage to the first handle well and thereby modifying the combined capacitance/voltage curve.