Ferroelectric capacitor device
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsToru Nasu, Shinichiro Hayashi
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Abstract
The ferroelectric capacitor device includes a bottom electrode, a capacitor insulating film formed of a ferroelectric film, and a top electrode. The ferroelectric film has a bismuth layer structure including a plurality of bismuth oxide layers and a plurality of perovskite-like layers alternately put on top of each other. The plurality of bismuth oxide layers are formed of Bi2O2, and the plurality of perovskite-like layers include two or more kinds of layers represented by a general formula: Am−1BmO3m+α (where A is a univalent, divalent or trivalent metal, B is a tetravalent, pentavalent or hexavalent metal, m is an integer equal to or more than 1, at least one of A being Bi if m is an integer of 2 or more, and 0<α<1) and different in the value of m.
Claims14
A ferroelectric capacitor device comprising a bottom electrode, a capacitor insulating film formed of a ferroelectric film, and a top electrode,
- wherein the ferroelectric film has a bismuth layer structure including a plurality of bismuth oxide layers and a plurality of perovskite-like layers alternately put on top of each other,
- the plurality of bismuth oxide layers are formed of Bi2O2, and
- the plurality of perovskite-like layers includes two or more kinds of layers represented by general formula (1):
- Am−1BmO3m+α (where A is a univalent, divalent or trivalent metal, B is a tetravalent, pentavalent or hexavalent metal, m is an integer equal to or more than 1, at least one of A being Bi if m is an integer equal to or more than 2, and 0≦α≦1) and different in the value of m from each other.
A ferroelectric capacitor device comprising a bottom electrode, a capacitor is insulating film formed of a ferroelectric film, and a top electrode,
- wherein the ferroelectric film has a bismuth layer structure including a plurality of bismuth oxide layers and a plurality of perovskite-like layers alternately put on top of each other,
- the plurality of bismuth oxide layers are formed of Bi2O2, and
- the plurality of perovskite-like layers include at least one first layer represented by general formula (2):
- BO3+α (where B is a tetravalent, pentavalent or hexavalent metal and 0<α<1) and at least one second layer represented by general formula (3):
- Am−1BmO3m+1 (where A is a univalent, divalent or trivalent metal, and m is an integer equal to or more than 2, at least one of A being Bi).
A ferroelectric capacitor device comprising a bottom electrode, a capacitor insulating film formed of a ferroelectric film, and a top electrode,
- wherein the ferroelectric film has a bismuth layer structure including a plurality of bismuth oxide layers and a plurality of perovskite-like layers alternately put on top of each other,
- the plurality of bismuth oxide layers are formed of Bi2O2, and
- the plurality of perovskite-like layers include at least one first layer represented by general formula (4):
- BO7/2 (where B is a pentavalent metal) and at least one second layer represented by general formula (5):
- (A1−xBi2x/3)B2O7 (where A is a divalent metal, B is a pentavalent metal, and 0<x<1).
A ferroelectric capacitor device comprising a bottom electrode, a capacitor insulating film formed of a ferroelectric film, and a top electrode,
- wherein the ferroelectric film has a bismuth layer structure including a plurality of bismuth oxide layers and a plurality of perovskite-like layers alternately put on top of each other,
- the plurality of bismuth oxide layers are formed of Bi2O2, and
- the plurality of perovskite-like layers include at least one first layer represented by general formula (6):
- B1O7/2 (where B1 is a pentavalent metal) and at least one second layer represented by general formula (7):
- (Al-xBix)B12−xB2xO7 (where A is a divalent metal, B1 is a pentavalent metal, B2 is a tetravalent metal, and 0<x<1).
A ferroelectric capacitor device comprising a bottom electrode, a capacitor insulating film formed of a ferroelectric film, and a top electrode,
- wherein the ferroelectric film has a bismuth layer structure including a plurality of bismuth oxide layers and a plurality of perovskite-like layers alternately put on top of each other,
- the plurality of bismuth oxide layers are formed of Bi2O2, and the plurality of perovskite-like layers include at least one first layer represented by general formula (8):
- BO3 (where B is a tetravalent metal) and at least one second layer represented by general formula (9):
- (A1−xBix)2B3O10 (where A is a trivalent metal, B is a tetravalent metal, and 0<x<1).
A ferroelectric capacitor device comprising a bottom electrode, a capacitor insulating film formed of a ferroelectric film, and a top electrode,
- wherein the ferroelectric film has a bismuth layer structure including a plurality of bismuth oxide layers and a plurality of perovskite-like layers alternately put on top of each other,
- the plurality of bismuth oxide layers are formed of Bi2O2, and
- the plurality of perovskite-like layers include at least one first layer represented by general formula (10):
- (A1−xBix)B2O7 (where A is a trivalent metal, B is a tetravalent metal, and 0<x<1) and at least one second layer represented by general formula (11):
- (A1−xBix)2B3O10 (where A is a trivalent metal, B is a tetravalent metal, and 0<x<1).
Dependencies are inferred from the claim text.