CN-122029624-A - Dielectric, capacitor, circuit board, device, and power storage device

Abstract

Dielectrics of the present disclosure include oxides containing hafnium, zirconium, and gallium. In the dielectric, the molar ratio Zr/(Hf+Zr) of the content of zirconium relative to the sum of the content of hafnium and the content of zirconium is 0.2 or more and less than 1. Further, the molar ratio Ga/(Hf+Zr+Ga) of the content of gallium relative to the sum of the content of hafnium, the content of zirconium and the content of gallium is more than 0 and less than 0.14.

Inventors

• TAKEUCHI HIROKI
• KAZUHITO HATO
• MORIMOTO KOTA
• SAKIYAMA SATOSHI

Assignees

• 松下知识产权经营株式会社

Dates

Publication Date

20260512

Application Date

20240823

Priority Date

20231018

Claims (13)

1. 1. A dielectric comprising an oxide comprising hafnium, zirconium and gallium, The molar ratio of the content of zirconium to the sum of the content of hafnium and the content of zirconium is 0.2 or more and less than 1, The molar ratio of the content of gallium to the sum of the content of hafnium, the content of zirconium and the content of gallium is greater than 0 and less than 0.14.
2. 2. A dielectric according to claim 1, The molar ratio of the zirconium content to the sum of the hafnium content and the zirconium content is 0.2 or more and 0.8 or less, The molar ratio of the content of gallium to the sum of the content of hafnium, the content of zirconium and the content of gallium is greater than 0 and less than 0.06.
3. 3. A dielectric according to claim 1, The dielectric has a composition represented by Hf 1-x-y Zr x Ga y O 2±δ , The composition satisfies the conditions of 0.2≤x/(1-y) <1 and 0< y < 0.14.
4. 4. A dielectric according to claim 3, The composition further satisfies the conditions of 0.2 < x/(1-y) < 0.8 and 0< y < 0.06.
5. 5. A dielectric according to claim 1, The dielectric includes a fluorite structure.
6. 6. A dielectric according to claim 1, The dielectric includes at least one selected from tetragonal and orthorhombic phases.
7. 7. A capacitor includes a first electrode, a second electrode, and a dielectric disposed between the first electrode and the second electrode, The dielectric is the dielectric of claim 1.
8. 8. The capacitor according to claim 7, The first electrode includes at least one selected from aluminum, titanium nitride, titanium oxide, molybdenum, tungsten, tantalum, zirconium, hafnium, niobium, titanium, silicon, zinc oxide, indium oxide, and tin oxide.
9. 9. The capacitor according to claim 7, The second electrode includes at least one selected from the group consisting of conductive polymers, manganese oxide, zinc oxide, indium oxide, tin oxide, titanium nitride, titanium oxide, an electrolyte, and polysilicon.
10. 10. A circuit comprising the capacitor according to any one of claims 7 to 9.
11. 11. A circuit board provided with the capacitor according to any one of claims 7 to 9.
12. 12. An apparatus comprising the capacitor of any one of claims 7 to 9.
13. 13. A power storage device comprising the capacitor according to any one of claims 7 to 9.

Description

Dielectric, capacitor, circuit board, device, and power storage device Technical Field The present disclosure relates to dielectrics, capacitors, circuits, circuit boards, devices, and power storage apparatuses. Background Conventionally, it is known that dielectric characteristics can be changed by substituting a part of Hf with another element in HfO 2. For example, non-patent document 1 describes that various dopants such as Si, zr, al, Y, gd, sr and La impart ferroelectricity and antiferroelectricity to a HfO 2 thin film. Patent document 1 describes a capacitor having a dielectric layer made of a metal oxide containing Hf, bi, and an element having a valence of 5 or more. The element having a valence of 5 or more is selected from Nb, ta, mo and W, for example. The capacitor can exhibit antiferroelectric properties. Prior art literature Patent literature Patent document 1 International publication No. 2019/208340 Non-patent literature Non-patent document 1:Advanced Materials (advanced materials), (Germany), 2015,27,1811-1831 Disclosure of Invention The present disclosure provides dielectrics that are advantageous from the standpoint of large capacity energy storage (large capacitive storage: high-CAPACITANCE ENERGY storage). The dielectric of the present disclosure comprises an oxide comprising hafnium, zirconium and gallium, The molar ratio of the content of zirconium to the sum of the content of hafnium and the content of zirconium is 0.2 or more and less than 1, The molar ratio of the content of gallium to the sum of the content of hafnium, the content of zirconium and the content of gallium is greater than 0 and less than 0.14. According to the present disclosure, a dielectric advantageous from the viewpoint of large-capacity energy storage can be provided. Drawings Fig. 1 is a cross-sectional view showing an example of a capacitor of the present disclosure. Fig. 2 is a cross-sectional view showing another example of the capacitor of the present disclosure. Fig. 3A is a diagram schematically showing an example of the circuit of the present disclosure. Fig. 3B is a diagram schematically illustrating an example of the circuit board of the present disclosure. Fig. 3C is a diagram schematically showing an example of the apparatus of the present disclosure. Fig. 3D is a diagram schematically illustrating an example of the power storage device of the present disclosure. Fig. 4 is a graph showing an X-ray diffraction (XRD) pattern of the dielectric of example 1. Fig. 5 is a graph showing the relationship between polarization and electric field strength in the capacitor of example 1. Fig. 6 is a graph showing the relationship between polarization and electric field strength in the capacitor of example 6. Fig. 7 is a graph showing the relationship between polarization and electric field strength in the capacitor of comparative example 1. Fig. 8 is a graph showing the relationship between the molar ratio Ga/(hf+zr+ga) and the molar ratio Zr/(hf+zr) in the dielectrics of the examples and the comparative examples. Detailed Description (Insight underlying the present disclosure) When a voltage is applied to the antiferroelectric body, if the electric field strength becomes large, the relative dielectric constant of the antiferroelectric body increases, and the antiferroelectric body has a nonlinear dielectric characteristic. Antiferroelectric is envisaged for use in high voltage applications. In addition, the paraelectric body (PARAELECTRICS) exhibits a constant relative permittivity with respect to a change in electric field strength, and is advantageous from the viewpoint of ease of design of the device. HfO 2 readily contains both antiferroelectric and ferroelectric phases. If a ferroelectric phase is present, remnant polarization is easily generated. Therefore, when HfO 2 is used in a capacitor application, it is difficult to increase the capacity of energy storage. For example, when HfO 2 partially containing a ferroelectric phase is used for a dielectric layer of a capacitor, remnant polarization occurs even in a state where an external electric field is 0. By this remnant polarization, the energy output when the capacitor discharges is easily reduced. In view of such circumstances, the present inventors have intensively studied whether or not the capacity of energy storage in a dielectric containing an oxide containing hafnium can be increased. The inventors of the present invention have repeatedly performed a large number of trial and error, and as a result, have newly found that the residual polarization of a dielectric can be reduced from the maximum polarization by including oxides containing hafnium, zirconium and gallium and adjusting the contents of these elements to a predetermined relationship. The inventors have studied the dielectrics of the present disclosure based on this new insight. (Embodiment) Embodiments of the present disclosure will be described below with reference to the drawings. The