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KR-102962648-B1 - CAPACITOR, METHOD OF CONTROLLING THE SAME, AND TRANSISTOR INCLUDING THE SAME

KR102962648B1KR 102962648 B1KR102962648 B1KR 102962648B1KR-102962648-B1

Abstract

The capacitor comprises a first electrode, a second electrode provided on the first electrode, a ferroelectric film provided between the first electrode and the second electrode, and a dielectric film provided between the ferroelectric film and the second electrode, and the impedance of the ferroelectric film and the impedance of the dielectric film are determined such that the control voltage applied between the first electrode and the second electrode matches the capacitance boosting operating voltage, and the capacitance boosting operating voltage is determined by the following equation. (V MAX : Capacitance boosting operating voltage, Z 1 : Impedance of the ferroelectric film, Z 2 : Impedance of the dielectric film, t F : Thickness of the ferroelectric film, E FM : Electric field applied to the ferroelectric film at which the change in polarization of the ferroelectric film is maximum)

Inventors

  • 이재호
  • 박보은
  • 김용성
  • 이주호

Assignees

  • 삼성전자주식회사

Dates

Publication Date
20260507
Application Date
20250402

Claims (20)

  1. Voltage controller; First electrode; A second electrode provided on the first electrode; A ferroelectric film provided between the first electrode and the second electrode; and A dielectric film provided between the ferroelectric film and the second electrode; comprising The voltage controller applies a control voltage equal to the capacitance boosting operating voltage between the first electrode and the second electrode, and The above capacitance boosting operating voltage is a capacitor determined by the following equation. (V MAX : Capacitance boosting operating voltage, Z 1 : Impedance of the ferroelectric film, Z 2 : Impedance of the dielectric film, t F : Thickness of the ferroelectric film, E FM : Electric field applied to the ferroelectric film at which the change in polarization of the ferroelectric film is maximum)
  2. In Article 1, The above ferroelectric film includes a conductance component and a capacitance component connected in parallel, and The above dielectric film is a capacitor comprising a parallel-connected conductance component and a capacitance component.
  3. In Article 1, The above capacitance boosting operating voltage is determined by the following equation, and The angular frequency of the above control voltage is determined such that the control voltage matches the capacitance boosting operating voltage. ( G1 : Conductance of the ferroelectric film, C1 : Capacitance of the ferroelectric film, G2 : Conductance of the dielectric film, C2 : Capacitance of the dielectric film, ω: Angular frequency of the control voltage, Ps: Polarization of the ferroelectric film when an electric field of E FM is applied to the ferroelectric film, α: Stability parameter, β: Skewness parameter)
  4. In Article 1, The ratio of the magnitudes of the impedance of the ferroelectric film and the impedance of the dielectric film ( ) is a capacitor greater than or equal to 0.01.
  5. In Article 1, A capacitor in which the current density of the current passing through the dielectric film and the ferroelectric film is 1 mA/ cm² or less.
  6. In Article 1, A capacitor in which the spontaneous polarization of the above ferroelectric film is 20 μC/ cm² or greater.
  7. In Article 1, A capacitor in which the dielectric dissipation factor of the above dielectric film is 0.1 or less.
  8. A capacitor control method comprising a voltage controller, a first electrode, a second electrode provided on the first electrode, a ferroelectric film provided between the first electrode and the second electrode, and a dielectric film provided between the ferroelectric film and the second electrode, wherein The voltage controller applies a control voltage equal to the capacitance boosting operating voltage between the first electrode and the second electrode, and A capacitor control method in which the above capacitance boosting operating voltage is determined by the following equation. (V MAX : Capacitance boosting operating voltage, Z 1 : Impedance of the ferroelectric film, Z 2 : Impedance of the dielectric film, t F : Thickness of the ferroelectric film, E FM : Electric field applied to the ferroelectric film at which the change in polarization of the ferroelectric film is maximum)
  9. In Article 8, The above ferroelectric film includes a conductance component and a capacitance component connected in parallel, and A capacitor control method comprising a dielectric film having a parallel-connected conductance component and a capacitance component.
  10. In Article 8, The method further comprises controlling the angular frequency of the control voltage so that the control voltage matches the capacitance boosting operating voltage. A capacitor control method in which the above capacitance boosting operating voltage is determined by the following equation. ( G1 : Conductance of the ferroelectric film, C1 : Capacitance of the ferroelectric film, G2 : Conductance of the dielectric film, C2 : Capacitance of the dielectric film, ω: Angular frequency of the control voltage, Ps: Polarization of the ferroelectric film when an electric field of E FM is applied to the ferroelectric film, α: Stability parameter, β: Skewness parameter)
  11. In Article 8, The ratio of the magnitudes of the impedance of the ferroelectric film and the impedance of the dielectric film ( A capacitor control method in which ) is 0.01 or greater.
  12. In Article 8, A capacitor control method in which the current density of the current passing through the dielectric film and the ferroelectric film is 1 mA/cm² or less when the above control voltage matches the above capacitance boosting operating voltage.
  13. In Article 8, A capacitor control method in which the spontaneous polarization of the above ferroelectric film is 20 μC/ cm² or higher.
  14. In Article 8, A capacitor control method in which the dielectric dissipation factor of the above dielectric film is 0.1 or less.
  15. Voltage controller; Substrate; and A gate structure provided on the above substrate; comprising, The above substrate includes a source region and a drain region spaced apart from each other with the gate structure in between, and The gate structure comprises a dielectric film, a ferroelectric film, and a gate electrode provided sequentially on the substrate, and The voltage controller applies a control voltage equal to the capacitance boosting operating voltage between the gate electrode and the substrate, and A transistor in which the above capacitance boosting operating voltage is determined by the following equation. (V MAX : Capacitance boosting operating voltage, Z 1 : Impedance of the ferroelectric film, Z 2 : Impedance of the dielectric film, t F : Thickness of the ferroelectric film, E FM : Electric field applied to the ferroelectric film at which the change in polarization of the ferroelectric film is maximum)
  16. In Article 15, The above ferroelectric film includes a conductance component and a capacitance component connected in parallel, and The above dielectric film is a transistor comprising a parallel-connected conductance component and a capacitance component.
  17. In Article 15, The above capacitance boosting operating voltage is determined by the following equation, and A transistor in which the angular frequency of the above control voltage is determined such that the control voltage matches the capacitance boosting operating voltage. (G1: Conductance of the ferroelectric film, C1: Capacitance of the ferroelectric film, G2: Conductance of the dielectric film, C2: Capacitance of the dielectric film, ω: Angular frequency of the control voltage, Ps: Polarization of the ferroelectric film when an electric field of E FM is applied to the ferroelectric film, α: Stability parameter, β: Skewness parameter)
  18. In Article 15, The ratio of the magnitudes of the impedance of the ferroelectric film and the impedance of the dielectric film ( ) is a transistor with a value of 0.01 or greater.
  19. In Article 15, A transistor in which the current density of the current passing through the dielectric film and the ferroelectric film is 1 mA/ cm² or less.
  20. In Article 15, A transistor in which the spontaneous polarization of the above ferroelectric film is 20 μC/ cm² or greater.

Description

Capacitor, Method of Controlling the Same, and Transistor Including the Same The present disclosure relates to a capacitor, a capacitor control method, and a transistor including the same. With technological advancements, the size of devices such as transistors and capacitors is shrinking. Scaled-down devices have limited thickness. Consequently, there is an increasing demand for materials and structures with high dielectric constants. In relation to materials and structures with high dielectric constant, the capacitance boosting effect using negative capacitance is being studied. The capacitance boosting effect can refer to a significant increase in dielectric constant when a predetermined voltage is applied to a capacitor. FIG. 1 is a cross-sectional view of a capacitor according to an exemplary embodiment. Figure 2 is a circuit diagram of the capacitor in Figure 1. FIG. 3 is a cross-sectional view of a transistor according to an exemplary embodiment. Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. In the drawings below, the same reference numerals refer to the same components, and the size of each component in the drawings may be exaggerated for clarity and convenience of explanation. Meanwhile, the embodiments described below are merely illustrative, and various modifications are possible from these embodiments. In the following, terms described as "upper" or "upper" may include not only those directly above in contact, but also those above without contact. A singular expression includes a plural expression unless the context clearly indicates otherwise. Furthermore, when a part is said to "include" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components. FIG. 1 is a cross-sectional view of a capacitor according to exemplary embodiments. FIG. 2 is a circuit diagram corresponding to the capacitor of FIG. 1. Referring to FIG. 1 and FIG. 2, a capacitor (10) may be provided comprising a first electrode (310), a ferroelectric film (100), a dielectric film (200), and a second electrode (320). The ferroelectric film (100) may comprise a ferroelectric material. A ferroelectric material refers to an insulator or dielectric material exhibiting spontaneous polarization, which is distinguished from a multiferroic material exhibiting two or more ferroelectric properties, such as ferroelectric, ferroelastic, ferromagnetic, antiferromagnetic, etc. For example, the ferroelectric material may comprise at least one of an oxide ferroelectric material, a polymer ferroelectric material, a fluoride ferroelectric material such as BMF ( BaMgF₄ ), and/or a ferroelectric semiconductor. Oxide ferroelectrics include, for example, perovskite ferroelectrics such as PZT (PbZr x Ti 1-x O 3 ), BaTiO 3 , and PbTiO 3 ; pseudo-ilmenite ferroelectrics such as LiNbO 3 and LiTaO 3 ; tungsten-bronze (TB) ferroelectrics such as PbNb 3 O 6 and Ba 2 NaNb 5 O 15; bismuth layered ferroelectrics such as SBT (SrBi 2 Ta 2 O 9 ), BLT ((Bi,La) 4 Ti 3 O 12 ), and Bi 4 Ti 3 O 12 ; pyrochlore ferroelectrics such as HfZrO 2 and La2Ti2O7; solid solutions of these ferroelectrics; as well as rare earth elements such as Y, Er, Ho, Tm, Yb, and Lu. It may include RMnO3 containing element (R) and PGO ( Pb₅Ge₃O₁¹ ). The polymeric ferroelectric may include, for example, at least one of polyvinylidene fluoride (PVDF), a polymer containing PVDF, a copolymer, a terpolymer, a cyanopolymer, polymers thereof, and/or copolymers. The ferroelectric semiconductor may include, for example, group 2-6 compounds such as CdZnTe, CdZnS, CdZnSe, CdMnS, CdFeS, CdMnSe, and CdFeSe. Ferroelectric materials may have spontaneous polarization. For example, the spontaneous polarization of the ferroelectric film (100) may be 20 μC/ cm² or greater. The ferroelectric film (100) may include a conductance component and a capacitance component connected in parallel. The impedance of the ferroelectric film (100) will be described later. The dielectric film (200) may have a material capable of realizing a desired capacitance. As the integration density of the integrated circuit element equipped with the capacitor (10) increases, the space occupied by the capacitor (10) gradually decreases, and therefore, a dielectric with a high dielectric constant may be preferred. The dielectric film (200) may include a material with a high dielectric constant. A high dielectric constant may mean a dielectric constant higher than that of silicon oxide. In one embodiment, the dielectric film (200) may be a metal oxide comprising at least one metal selected from Ca, Sr, Ba, Sc, Y, La, Ti, Hf, Zr, Nb, Ta , Ce, Pr, Nd, Gd, Dy, Yb , and Lu. For example, the dielectric film (200) may include HfO2 , ZrO2 , CeO2 , La2O3 , Ta2O3 , or TiO2 . The dielectric film (200) may have a single-layer structure or a multi-layer structure. The dielectric film (200) may h