Ferroelectric capacitor, method of manufacturing same, and semiconductor memory device
AssigneeNEC Electronics Corporation
InventorTakashi Hase
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Abstract
Disclosed is a ferroelectric capacitor in which polarization of a ferroelectric thin film can readily be reversed and polarization-reversal charge increased. The ferroelectric capacitor has a bottom electrode, a ferroelectric thin film and a top electrode. The top electrode comprises Ru1-xOx (where X is equal to or greater than 0.005 and equal to or less than 0.05, that is, the oxygen content in the Ru metal is 0.5 to 5 atm %) and has an Ru metal crystalline phase.
Claims28
A ferroelectric capacitor having a bottom electrode, a ferroelectric thin film provided on the bottom electrode, and a top electrode provided on the ferroelectric thin film, wherein
- said top electrode comprises Ru1-xOx (where X is equal to or greater than 0.005 and equal to or less than 0.05) and has an Ru metal crystalline phase.
A ferroelectric capacitor having a bottom electrode, a ferroelectric thin film provided on the bottom electrode, and a top electrode provided on the ferroelectric thin film, wherein
- either one or both of said top electrode and bottom electrode comprises Ru1-xOx (where X is equal to or greater than 0.005 and equal to or less than 0.05) and has an Ru metal crystalline phase.
A ferroelectric capacitor having a bottom electrode, a ferroelectric thin film provided on the bottom electrode, and a top electrode provided on the ferroelectric thin film, wherein
- said top electrode comprises a metal that has a metal crystalline phase, contains oxygen and is devoid of a metal oxide crystalline phase.
A ferroelectric capacitor having first and second electrodes, and a ferroelectric thin film arranged between said first and second electrodes, wherein
- at least one of said first and second electrodes comprises a metal that has a metal crystalline phase, contains oxygen and is devoid of a metal oxide crystalline phase.
A method of manufacturing a ferroelectric capacitor, said method comprising:
- a step of forming a bottom electrode;
- a step of forming a ferroelectric thin film on the bottom electrode;
- and
- a step of forming a top electrode on the ferroelectric thin film,
- said method further comprising a step of controlling flow-rate ratio of inert gas to oxygen gas, when an electrode layer of at least one of said bottom electrode and said top electrode is formed by sputtering an Ru metal target in an atmosphere that contains oxygen, to set the oxygen content X in Ru1-xOx, which is formed as the electrode layer, to a value equal to or greater than 0.005 and equal to or less than 0.05.
A method of manufacturing a ferroelectric capacitor, said method comprising:
- a step of forming a bottom electrode;
- a step of forming a ferroelectric thin film on the bottom electrode;
- and
- a step of forming a top electrode on the ferroelectric thin film,
- said method further comprising a step of controlling flow-rate ratio of inert gas to oxygen gas, when an electrode layer of at least one of said bottom electrode and said top electrode is formed by sputtering of a metal target in an atmosphere that contains oxygen, to control the oxygen content of a metal thin film formed as the electrode layer.
A method of manufacturing a ferroelectric capacitor, said method comprising:
- a step of forming a bottom electrode;
- a step of forming a ferroelectric thin film on the bottom electrode;
- and
- a step of forming a top electrode on the ferroelectric thin film,
- said method further comprising a step of controlling supplied amount of oxidizing gas, when an electrode layer of at least one of said bottom electrode and said top electrode is formed by causing a gaseous 10 phase reaction between supplied organic metal material and oxidization gas, to control the oxygen content of a metal thin film formed as the electrode layer.
Dependencies are inferred from the claim text.