Ferroelectric film containing a perovskite structure oxide and method for manufacturing a ferroelectric film
A method for manufacturing a ferroelectric film including the steps of forming a burnable material film containing hydrogen of not less than 1% by weight on a substrate; forming an amorphous thin film including a ferroelectric material on the burnable material film; and oxidizing and crystallizing the amorphous thin film while supplying hydrogen to the amorphous thin film by burning the burnable material film through heating of the burnable material film and the amorphous thin film in an oxygen atmosphere, to thereby form a first ferroelectric film on the substrate.
1. A method for manufacturing a ferroelectric film, comprising the steps of:
forming a burnable material film containing hydrogen of not less than 1% by weight on a substrate;
forming an amorphous thin film including a ferroelectric material on said burnable material film; and
oxidizing and crystallizing said amorphous thin film while supplying hydrogen to said amorphous thin film by burning said burnable material film through heating of said burnable material film and said amorphous thin film in an oxygen atmosphere, to thereby form a first ferroelectric film on said substrate, wherein:
said first ferroelectric film includes a perovskite structure oxide;
said first ferroelectric film is oriented in any of (001), (001)+(110), (110), (110)+(111), and (111), when said amorphous thin film is heated in an oxygen atmosphere, by increase in an oxygen supply amount, as a pressurized oxygen atmosphere;
a pressure of the pressurized oxygen atmosphere when said first ferroelectric film is oriented in (001) is lower than a pressure of the pressurized oxygen atmosphere when said first ferroelectric film is oriented in (001)+(110);
a pressure of the pressurized oxygen atmosphere when said first ferroelectric film is oriented in (001)+(110) is lower than a pressure of the pressurized oxygen atmosphere when said first ferroelectric film is oriented in (110);
a pressure of the pressurized oxygen atmosphere when said first ferroelectric film is oriented in (110) is lower than a pressure of the pressurized oxygen atmosphere when said first ferroelectric film is oriented in (110)+(111); and
a pressure of the pressurized oxygen atmosphere when said first ferroelectric film is oriented in (110)+(111) is lower than a pressure of the pressurized oxygen atmosphere when said first ferroelectric film is oriented in (111).
2. The method for manufacturing a ferroelectric film according to claim 1 , wherein said burnable material film is a C x N y H z film, a carbon film or a DLC film, and x, y and z satisfy following Formulae (i) and (ii):
0.1 ≦z (i)
x+y+z= 1 (ii).
3. The method for manufacturing a ferroelectric film according to claim 1 , wherein
said first ferroelectric film includes at least one of:
perovskite or a bismuth layered structure oxide represented by ABO 3 or (Bi 2 O 2 ) 2+ (A m−1 B m O 3m+1 ) 2− (wherein A is at least one kind selected from the group consisting of Li, Na, K, Rb, Pb, Ca, Sr, Ba, Bi, La and Hf, B is at least one kind selected from the group consisting of Ru, Fe, Ti, Zr, Nb, Ta, V, W and Mo, and m is a natural number of not more than 5;
a superconductive oxide represented by LanBa 2 Cu 3 O 7 , Trm 2 Ba 2 Ca n−1 Cu n O 2n+4 or TrmBa 2 Ca n−1 Cu n O 2+3 (wherein Lan is at least one kind selected from the group consisting of Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu, Trm is at least one kind selected from the group consisting of Bi, Tl and Hg, and n is a natural number of not more than 5;
a tungsten bronze structure oxide represented by A 0.5 BO 3 (tetragonal bronze structure) or A 0.3 BO 3 (hexagonal bronze structure) (wherein A is at least one kind selected from the group consisting of Li, Na, K, Rb, Cs, Pb, Ca, Sr, Ba, Bi and La, and B is at least one kind selected from the group consisting of Ru, Fe, Ti, Zr, Nb, Ta, V, W and Mo;
a material of at least one kind selected from the group consisting of CaO, BaO, PbO, ZnO, MgO, B 2 O 3 , Al 2 O 3 , Y 2 O 3 , La 2 O 3 , Cr 2 O 3 , Bi 2 O 3 , Ga 2 O 3 , ZrO 2 , TiO 2 , HfO 2 , NbO 2 , MoO 3 , WO 3 and V 2 O 5 ;
a material including SiO 2 in the at least one kind of material; and
a material including SiO 2 and GeO 2 in the at least one kind of material.
4. The method for manufacturing a ferroelectric film according to claim 1 , wherein:
said first ferroelectric film includes a perovskite structure oxide; and
said first ferroelectric film is oriented in any of (001), (001)+(110), (110), (110)+(111) and (111) by increasing a thickness of said burnable material film.
5. The method for manufacturing a ferroelectric film according to claim 4 , wherein:
a thickness of said burnable material film when said first ferroelectric film is oriented in (001) is smaller than a thickness of said burnable material film when said first ferroelectric film is oriented in (001)+(110);
a thickness of said burnable material film when said first ferroelectric film is oriented in (001)+(110) is smaller than a thickness of said burnable material film when said first ferroelectric film is oriented in (110);
a thickness of said burnable material film when said first ferroelectric film is oriented in (110) is smaller than a thickness of said burnable material film when said first ferroelectric film is oriented in (110)+(111); and
a thickness of said burnable material film when said first ferroelectric film is oriented in (110)+(111) is smaller than a thickness of said burnable material film when said first ferroelectric film is oriented in (111).
6. The method for manufacturing a ferroelectric film according to claim 4 , wherein
said burnable material film is a DLC film having a thickness of 0.1 nm to 300 nm.
7. The method for manufacturing a ferroelectric film according to claim 1 , wherein
said first ferroelectric film is a PZT film.
8. The method for manufacturing a ferroelectric film according to claim 1 , wherein:
an electrode is formed on said substrate; and
said first ferroelectric film is formed on said electrode.
9. The method for manufacturing a ferroelectric film according to claim 1 , wherein
a thickness of said amorphous thin film is 5 nm to 450 nm.
10. The method for manufacturing a ferroelectric film according to claim 1 , furthermore comprising, after the step of forming said first ferroelectric film on a substrate, the step of forming an amorphous thin film including a ferroelectric material on said first ferroelectric film, and oxidizing and crystallizing said amorphous thin film by heating said amorphous thin film in an oxygen atmosphere, to thereby form a second ferroelectric film on said first ferroelectric film.
11. A ferroelectric film manufactured by the method for manufacturing a ferroelectric film according to claim 1 ,
wherein the ferroelectric film comprises a perovskite structure oxide, and wherein
a half-value width of the strongest peak in measurement results of any of (001), (110) and (111) orientations by X-ray diffraction is not more than 1.5°.
12. The method for manufacturing a ferroelectric film according to claim 1 , wherein
said first ferroelectric film includes at least one of:
perovskite or a bismuth layered structure oxide represented by ABO 3 or (Bi 2 O 2 ) 2+ (A m−1 B m O 3m+1 ) 2− , wherein A is at least one kind selected from the group consisting of Li, Na, K, Rb, Pb, Ca, Sr, Ba, Bi, La and Hf, B is at least one kind selected from the group consisting of Ru, Fe, Ti, Zr, Nb, Ta, V, W and Mo, and m is a natural number of not more than 5;
a superconductive oxide represented by LanBa 2 Cu 3 O 7 , Trm 2 Ba 2 Ca n−1 Cu n O 2n+4 or TrmBa 2 Ca n−1 Cu n O 2n+3 , wherein Lan is at least one kind selected from the group consisting of Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu, Trm is at least one kind selected from the group consisting of Bi, Tl and Hg, and n is a natural number of not more than 5;
a tungsten bronze structure oxide represented by A 0.5 BO 3 (tetragonal bronze structure) or A 0.3 BO 3 (hexagonal bronze structure), wherein A is at least one kind selected from the group consisting of Li, Na, K, Rb, Cs, Pb, Ca, Sr, Ba, Bi and La, and B is at least one kind selected from the group consisting of Ru, Fe, Ti, Zr, Nb, Ta, V, W and Mo;
a material of at least one kind selected from the group consisting of CaO, BaO, PbO, ZnO, MgO, B 2 O 3 , Al 2 O 3 , Y 2 O 3 , La 2 O 3 , Cr 2 O 3 , Bi 2 O 3 , Ga 2 O 3 , ZrO 2 , TiO 2 , HfO 2 , NbO 2 , MoO 3 , WO 3 and V 2 O 5 ;
a material including SiO 2 in the at least one kind of material; and
a material including SiO 2 and GeO 2 in the at least one kind of material.
13. A method for manufacturing a ferroelectric film, comprising the steps of:
forming, on a substrate, an amorphous thin film including a burnable material containing hydrogen of not less than 1% by weight and a ferroelectric material; and
oxidizing and crystallizing said amorphous thin film while supplying hydrogen to said amorphous thin film by burning said burnable material through heating of said amorphous thin film in an oxygen atmosphere, to thereby form a first ferroelectric film on said substrate, wherein:
said first ferroelectric film includes a perovskite structure oxide;
said first ferroelectric film is oriented in any of (001), (001)+(110), (110), (110)+(111), and (111), when said amorphous thin film is heated in an oxygen atmosphere, by increase in an oxygen supply amount, as a pressurized oxygen atmosphere;
a pressure of the pressurized oxygen atmosphere when said first ferroelectric film is oriented in (001) is lower than a pressure of the pressurized oxygen atmosphere when said first ferroelectric film is oriented in (001)+(110);
a pressure of the pressurized oxygen atmosphere when said first ferroelectric film is oriented in (001)+(110) is lower than a pressure of the pressurized oxygen atmosphere when said first ferroelectric film is oriented in (110);
a pressure of the pressurized oxygen atmosphere when said first ferroelectric film is oriented in (110) is lower than a pressure of the pressurized oxygen atmosphere when said first ferroelectric film is oriented in (110)+(111); and
a pressure of the pressurized oxygen atmosphere when said first ferroelectric film is oriented in (110)+(111) is lower than a pressure of the pressurized oxygen atmosphere when said first ferroelectric film is oriented in (111).
14. The method for manufacturing a ferroelectric film according to claim 13 , wherein said burnable material is a carbon powder that supports hydrogen.
15. The method for manufacturing a ferroelectric film according to claim 13 , wherein
said first ferroelectric film is a PZT film.
16. The method for manufacturing a ferroelectric film according to claim 13 , wherein:
an electrode is formed on said substrate; and
said first ferroelectric film is formed on said electrode.
17. The method for manufacturing a ferroelectric film according to claim 13 , wherein
a thickness of said amorphous thin film is 5 nm to 450 nm.
18. The method for manufacturing a ferroelectric film according to claim 13 , furthermore comprising, after the step of forming said first ferroelectric film on a substrate, the step of forming an amorphous thin film including a ferroelectric material on said first ferroelectric film, and oxidizing and crystallizing said amorphous thin film by heating said amorphous thin film in an oxygen atmosphere, to thereby form a second ferroelectric film on said first ferroelectric film.
19. A ferroelectric film manufactured by the method for manufacturing a ferroelectric film according to claim 13 ,
wherein the ferroelectric film comprises a perovskite structure oxide, and wherein a half-value width of the strongest peak in measurement results of any of (001), (110) and (111) orientations by X-ray diffraction is not more than 1.5.
20. A ferroelectric film comprising a perovskite structure oxide, wherein
a half-value width of the strongest peak in measurement results of any of (001), (110) and (111) orientations by X-ray diffraction is not more than 1.5°.
21. An electronic component using said ferroelectric film according to claim 20 .