Thin film dielectric composite materials

• US 6,444,336 B1
• Filed: 12/21/2000
• Issued: 09/03/2002
• Est. Priority Date: 12/21/2000
• Status: Expired due to Fees

• Current Assignee: Los Alamos National Security LLC (Government of the United States of America)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Gibbons, Brady J., Park, Bae Ho, Jia, Quanxi, Findikoglu, Alp T.
• Primary Examiner(s): Jones, Deborah
• Assistant Examiner(s): SPERTY, ARDEN B
• Application Number:
  US09/747,212
• Publication Number:
  US 20020114957A1
• Time in Patent Office: 621 Days
• Field of Search: 501/134, 501/137, 428/699, 428/689, 428/701, 428/688, 428/469, 428/446
• US Class Current: 428/701
• CPC Class Codes: C04B 2235/3205 Alkaline earth oxides or oxide forming salts thereof, e.g. beryllium oxide
• CPC Class Codes: C04B 2235/3206 Magnesium oxides or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3208 Calcium oxide or oxide-forming salts thereof, e.g. lime
• CPC Class Codes: C04B 2235/3213 Strontium oxides or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3215 Barium oxides or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3217 Aluminum oxide or oxide forming salts thereof, e.g. bauxite, alpha-alumina
• CPC Class Codes: C04B 2235/3222 Aluminates other than alumino-silicates, e.g. spinel (MgAl2O4)
• CPC Class Codes: C04B 2235/3224 Rare earth oxide or oxide forming salts thereof, e.g. scandium oxide
• CPC Class Codes: C04B 2235/3227 Lanthanum oxide or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3232 Titanium oxides or titanates, e.g. rutile or anatase
• CPC Class Codes: C04B 2235/3234 Titanates, not containing zirconia
• CPC Class Codes: C04B 2235/3236 Alkaline earth titanates
• CPC Class Codes: C04B 2235/3244 Zirconium oxides, zirconates, hafnium oxides, hafnates, or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3249 containing also titanium oxide or titanates, e.g. lead zirconate titanate (PZT)
• CPC Class Codes: C04B 2235/3251 Niobium oxides, niobates, tantalum oxides, tantalates, or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3255 Niobates or tantalates, e.g. silver niobate
• CPC Class Codes: C04B 2235/3258 Tungsten oxides, tungstates, or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/326 Tungstates, e.g. scheelite
• CPC Class Codes: C04B 2235/3272 Iron oxides or oxide forming salts thereof, e.g. hematite, magnetite
• CPC Class Codes: C04B 2235/3274 Ferrites
• CPC Class Codes: C04B 2235/3275 : Cobalt oxides, cobaltates or cobaltites or oxide forming salts thereof, e.g. bismuth cobaltate, zinc cobaltite
• CPC Class Codes: C04B 2235/3284 : Zinc oxides, zincates, cadmium oxides, cadmiates, mercury oxides, mercurates or oxide forming salts thereof
• CPC Class Codes: C04B 2235/3293 : Tin oxides, stannates or oxide forming salts thereof, e.g. indium tin oxide [ITO]
• CPC Class Codes: C04B 2235/3296 : Lead oxides, plumbates or oxide forming salts thereof, e.g. silver plumbate
• CPC Class Codes: C04B 2235/80 : Phases present in the sintered or melt-cast ceramic products other than the main phase
• CPC Class Codes: C04B 35/46 : based on titanium oxides or titanates containing also zirconium or hafnium oxides, zirconates or hafnates C04B35/49
• CPC Class Codes: C04B 35/465 : based on alkaline earth metal titanates
• CPC Class Codes: C04B 35/472 : based on lead titanates
• CPC Class Codes: C04B 35/49 : containing also titanium oxides or titanates
• CPC Class Codes: C04B 35/495 : based on vanadium, niobium, tantalum, molybdenum or tungsten oxides or solid solutions thereof with other oxides, e.g. vanadates, niobates, tantalates, molybdates or tungstates
• CPC Class Codes: C04B 35/497 : based on solid solutions with lead oxides
• CPC Class Codes: C04B 35/499 : containing also titanates
• CPC Class Codes: C04B 35/50 : based on rare-earth compounds non-oxide rare earth compounds C04B35/5156
• CPC Class Codes: H01L 21/02186 : the material containing titanium, e.g. TiO2
• CPC Class Codes: H01L 21/02197 : the material having a perovskite structure, e.g. BaTiO3
• CPC Class Codes: H01L 21/022 : the layer being a laminate, i.e. composed of sublayers, e.g. stacks of alternating high-k metal oxides adhesion layers or buffer layers H01L21/02304, H01L21/02362
• CPC Class Codes: H01L 21/31691 : with perovskite structure

Abstract

A dielectric composite material comprising at least two crystal phases of different components with TiO₂ as a first component and a material selected from the group consisting of Ba_1−xSr_xTiO₃ where x is from 0.3 to 0.7, Pb_1−xCa_xTiO₃ where x is from 0.4 to 0.7, Sr_1−xPb_xTiO₃ where x is from 0.2 to 0.4, Ba_1−xCd_xTiO₃ where x is from 0.02 to 0.1, BaTi_1−xZr_xO₃ where x is from 0.2 to 0.3, BaTi_1−xSn_xO₃ where x is from 0.15 to 0.3, BaTi_1−xHf_xO₃ where x is from 0.24 to 0.3, Pb_1−1.3xLa_xTiO_3+0.2x where x is from 0.23 to 0.3, (BaTiO₃)_x(PbFeo_0.5Nb_0.5O₃)_1−x where x is from 0.75 to 0.9, (PbTiO₃)₋(PbCo_0.5W_0.5O₃)_1−x where x is from 0.1 to 0.45, (PbTiO₃)_x(PbMg_0.5W_0.5O₃)_1−x where x is from 0.2 to 0.4, and (PbTiO₃)_x(PbFe_0.5Ta_0.5O₃)_1−x where x is from 0 to 0.2, as the second component is described. The dielectric composite material can be formed as a thin film upon suitable substrates.

Claims

1. A dielectric composite material comprising at least two crystal phases of different components with TiO₂ as a first component and a material selected from the group consisting of Ba₁₋

xSr_xTiO₃ where x is from 0.3 to 0.7, Pb<sub>1−

x</sub>Ca_xTiO₃ where x is from 0.4 to 0.7, Sr<sub>1−

x</sub>Pb_xTiO₃ where x is from 0.2 to 0.4, Ba<sub>1−

x</sub>Cd_xTiO₃ where x is from 0.02 to 0.1, BaTi<sub>1−

x</sub>Zr_xO₃ where x is from 0.2 to 0.3, BaTi<sub>1−

x</sub>Sn_xO₃ where x is from 0.15 to 0.3, BaTi<sub>1−

x</sub>Hf_xO₃ where x is from 0.24 to 0.3, Pb<sub>1−

1.3Lax</sub>TiO_3+0.2x where x is from 0.23 to 0.3, (BaTiO₃)_x(PbFe_0.5Nb_0.5O₃)<sub>1−

x</sub> where x is from 0.75 to 0.9, (PbTiO₃)_x(PbCo_0.5W_0.5O₃)<sub>1−

x</sub> where x is from 0.1 to 0.45, (PbTiO₃)_x(PbMg_0.5W_0.5O₃)<sub>1−

x</sub>where x is from 0.2 to 0.4, and (PbTiO₃)_x(PbFe_0.5Ta_0.5O₃)<sub>1−

x</sub>where x is from 0 to 0.2, as the second component.

2. The dielectric composite material of claim 1 wherein said dielectric composite material is a thin film and is characterized as epitaxial upon a substrate selected from the group consisting of lanthanum aluminum oxide, magnesium oxide, and neodymium gadolinium oxide.

3. The dielectric composite material of claim 1 wherein said dielectric composite material is a thin film and is characterized as amorphous, polycrystalline or nanocrystalline upon a substrate selected from the group consisting of semiconductors, insulators, metals and metal alloys.

4. The dielectric composite material of claim 3 wherein said substrate is selected from the group consisting of silicon, sapphire and steel.

5. The dielectric composite material of claim 1 wherein said dielectric composite material includes from about 45 percent by weight to about 55 percent by weight of TiO₂ and from about 45 percent by weight to about 55 percent by weight of Ba₁₋

xSr_xTiO₃.

6. The dielectric composite material of claim 1 wherein said dielectric composite material includes from about 7 percent by weight to about 40 percent by weight of TiO₂ and from about 60 percent by weight to about 93 percent by weight of Ba₁₋

xSr_xTiO₃ and said dielectric composite material is characterized as a tunable dielectric material.

7. The dielectric composite material of claim 1 wherein said dielectric composite material includes about 10 percent by weight of TiO₂ and about 90 percent by weight of Ba₁₋

xSr_xTiO₃ and said dielectric composite material is characterized as a tunable dielectric material.

8. The dielectric composite material of claim 1 wherein said dielectric composite material includes about 50 percent by weight of TiO₂ and about 50 percent by weight of Ba₁₋

xSr_xTiO₃ and said dielectric composite material is characterized as having a dielectric loss of 0.001 or less.

9. A dielectric composite material comprising at least two crystal phases of different components, formed at high temperatures from TiO₂ and a material selected from the group consisting of Ba₁₋

xSr_xTiO₃ where x is from 0.3 to 0.7, Pb<sub>1−

x</sub>Ca_xTiO₃ where x is from 0.4 to 0.7, Sr<sub>1−

x</sub>Pb_xTiO₃ where x is from 0.2 to 0.4, Ba<sub>1−

x</sub>Cd_xTiO₃ where x is from 0.02 to 0.1, BaTi<sub>1−

x</sub>Zr_xO₃ where x is from 0.2 to 0.3, BaTi<sub>1−

x</sub>Sn_xO₃ where x is from 0.15 to 0.3, BaTi<sub>1−

x</sub>Hf_xO₃ where x is from 0.24 to 0.3, Pb<sub>1−

1.3x</sub>La_xTiO_3+0.2x wherei x is from 0.23 to 0.3, (BaTiO₃)_x(PbFe_0.5Nb_0.5O₃)<sub>1−

x</sub> where x is from 0.75 to 0.9, (PbTiO₃)_x(PbCo_0.5W_0.5O₃)<sub>1−

x</sub> where x is from 0.1 to 0.45, (PbTiO₃)_x(PbMg_0.5W_0.5O₃)<sub>1−

x</sub> where x is from 0.2 to 0.4, and (PbTiO₃)_x(PbFe_0.5Ta_0.5O₃)<sub>1−

x</sub> where x is from 0 to 0.2.

10. The dielectric composite material of claim 9 wherein said dielectric composite material is a thin film and is characterized as epitaxial upon a substrate selected from the group consisting of lanthanum aluminum oxide, magnesium oxide, and neodymium gadolinium oxide.

11. The dielectric composite material of claim 9 wherein said dielectric composite material is a thin film and is characterized as amorphous, polycrystalline or nanocrystalline upon a substrate selected from the group consisting of semiconductors, insulators, metals and metal alloys.

12. The dielectric composite material of claim 11 wherein said substrate is selected from the group consisting of silicon, sapphire and steel.

13. The dielectric composite material of claim 9 wherein said dielectric composite material includes from about 45 percent by weight to about 55 percent by weight of TiO₂ and from about 45 percent by weight to about 55 percent by weight of Ba₁₋

xSr_xTiO_3.

14. The dielectric composite material of claim 9 wherein said dielectric composite material includes from about 7 percent by weight to about 40 percent by weight of TiO₂ and from about 60 percent by weight to about 93 percent by weight of Ba₁₋

xSr_xTiO₃ and said dielectric composite material is characterized as a tunable dielectric material.

15. The dielectric composite material of claim 9 wherein said dielectric composite material includes about 10 percent by weight of TiO₂ and about 90 percent by weight of Ba₁₋

xSr_xTiO₃ and said dielectric composite material is characterized as a tunable dielectric material.

16. The dielectric composite material of claim 9 wherein said dielectric composite material includes about 50 percent by weight of TiO₂ and about 50 percent by weight of Ba₁₋

xSr_xTiO₃ and said dielectric composite material is characterized as having a dielectric loss of 0.001 or less.

17. A process of forming a thin film dielectric composite material including at least two crystal phases of different components with TiO₂ as a first component and a material selected from the group consisting of Ba₁₋

xSr_xTiO₃ where x is from 0.3 to 0.7, Pb<sub>1−

x</sub>Ca_xTiO₃ where x is from 0.4 to 0.7, Sr<sub>1−

x</sub>Pb_xTiO₃ where x is from 0.2 to 0.4, Ba<sub>1−

x</sub>Cd_xTiO₃ where x is from 0.02 to 0.1, BaTi<sub>1−

x</sub>Zr_xO₃ where x is from 0.2 to 0.3, BaTi<sub>1−

x</sub>Sn_xO₃ where x is from 0.15 to 0.3, BaTi<sub>1−

x</sub>Hf_xO₃ where x is from 0.24 to 0.3, Pb<sub>1−

1.3x</sub>La_xTiO_3+0.2x where x is from 0.23 to 0.3, (BaTiO₃)_x(PbFe_0.5Nb_0.5O₃)<sub>1−

x</sub> where x is from 0.75 to 0.9, (PbTiO₃)_x(PbCo_0.5W_0.5O₃)<sub>1−

x</sub> where x is from 0.1 to 0.45, (PbTiO₃)_x(PbMg_0.5W_0.5O₃)<sub>1−

x</sub> where x is from 0.2 to 0.4, and (PbTiO₃)_x(PbFe_0.5Ta_0.5O₃)<sub>1−

x</sub> where x is from 0 to 0.2, as the second component comprising;

forming a starting material including a mixture of TiO₂ and the material selected from the group consisting of Ba<sub>1−

x</sub>Sr_xTiO₃, Pb<sub>1−

x</sub>Ca_xTiO₃, Sr<sub>1−

x</sub>Pb_xTiO₃, Ba<sub>1−

x</sub>Cd_xTiO₃, BaTi<sub>1−

x</sub>Zr_xO₃, BaTi<sub>1−

x</sub>Sn_xO₃, BaTi<sub>1−

x</sub>Hf_xO₃, Pb<sub>1−

1.3x</sub>La_xTiO_3+0.2x, (BaTiO₃)_x(PbFe_0.5Nb_0.5O₃)<sub>1−

x</sub>, (PbTiO₃)_x(PbCo_0.5W_0.5O₃)<sub>1−

x</sub>, (PbTiO₃)_x(PbMg_0.5W_0.5O₃)<sub>1−

x</sub>, and (PbTiO₃)_x(PbFe_0.5Ta0.5O₃)<sub>1−

x</sub>;

depositing a thin film of the starting material on a substrate; and

,

heating the thin film of starting material for time and at temperatures sufficient to form said thin film dielectric composite material including at least two crystal phases of different components.

18. The process of claim 17 wherein said substrate is selected from the group consisting of lanthanum aluminum oxide, magnesium oxide, and neodymium gadolinium oxide.

19. The process of claim 17 wherein said substrate is selected from the group consisting of semiconductors, insulators, metals and metal alloys.

20. The process of claim 17 wherein said substrate is selected from the group consisting of silicon, sapphire and steel.