JPH11204734A - Electrode, capacitor, memory and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrode for improving characteristics of a part with which an electrode is connected, and a capacitor and a memory using this, and a method for manufacturing them. SOLUTION: A lower electrode 13, dielectric film 13, and upper electrode 15 are sequentially laminated through a joint layer 1,2 on a substrate 11. A first layer 13a made of IrPtRuO (oxygen content 10 atom %) and a second layer 13b made of ItPtRu or IrPtRuO (less than oxygen content 10 atom %) are laminated in the electrode 13, so that the second layer 13b can be arranged at the dielectric film 13. The first layer 13a can prevent diffusion with the dielectric film 14, and the second layer 13b can simplify the growth of crystal in the dielectric film 14 by a little diffusion generated in a boundary with the dielectric film 14. Thus, the crystallization of the dielectric film 14 being a part with which an electrode is connected can be made satisfactory, and characteristics can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrode connected to an electrode connecting portion such as a dielectric film, a capacitor and a memory using the same, and a method of manufacturing the same.

[0002]

2. Description of the Related Art At present, in the field of semiconductor devices,
RAM (Dynamic Random Access Memory) and FeRAM
Various semiconductor devices using a dielectric film such as (Ferroelectric Random Access Memories) have been developed, and various studies have been made on electrodes connected to the dielectric film. Conventionally, as such an electrode, in order to prevent an oxide layer having high electric resistance from being formed at the interface between the dielectric film and the electrode, a metal belonging to the platinum group which is hardly oxidized, Is also ruthenium oxide (R
uO ₂ ) or an oxide composed of lanthanum (La), strontium (Sr), cobalt (Co), and oxygen (O) has been used.

However, in forming a dielectric film, 600
Although heating at a high temperature of about 800 ° C. is usually required, these materials do not have excellent heat resistance, so that heating causes interdiffusion of constituent elements at the interface between the electrode and the dielectric film, There is a problem that a deteriorated layer is formed. Therefore, the thickness of the dielectric film is particularly set to 100
When the thickness was reduced to less than nm, good characteristics could not be obtained. Further, in a semiconductor device, when a capacitor and a transistor are joined by a plug layer made of silicon (Si) or tungsten (W), mutual diffusion of constituent elements and oxidation of the plug layer also occur at the interface between the electrode and the plug layer. Then, there is also a problem that their contact resistance becomes abnormally high.

[0004] In order to solve these problems,
Conventionally, the electrode is made of iridium oxide (IrO) having excellent heat resistance.
₂ ) and platinum oxide (PtO). With this configuration, even when the dielectric film is formed on the surface of the electrode at a high temperature of about 700 to 800 ° C. for about one hour, the interface between the electrode and the dielectric film and the contact between the electrode and the plug layer can be formed. Mutual diffusion of constituent elements at the interface can be prevented.

[0005]

However, with such a structure, the mutual diffusion of the constituent elements does not occur at the interface between the electrode and the dielectric film, and conversely, it is difficult to form a good crystal in the dielectric film. However, there is a problem that good characteristics (ferroelectric or high dielectric properties) cannot be obtained.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an electrode capable of improving the characteristics of a portion to be connected to an electrode, a capacitor and a memory using the same, and a method of manufacturing the same. Is to do.

[0007]

An electrode according to the present invention is connected to an electrode connecting portion, and has a first layer in which the degree of diffusion of constituent elements differs from the electrode connecting portion. And a second layer.

In the capacitor according to the present invention, a pair of electrodes are respectively connected to a dielectric film, and at least one of the pair of electrodes has a degree of diffusion of constituent elements between the dielectric film and the dielectric film. It has a different first layer and second layer.

A memory according to the present invention includes a capacitor having a pair of electrodes connected to a dielectric film, wherein the capacitor is provided between at least one of the pair of electrodes and the dielectric film. It has a first layer and a second layer that differ in the degree of diffusion of elements.

According to a method of manufacturing an electrode according to the present invention, an electrode connected to an electrode-connected portion is manufactured.
The method includes the steps of forming a first layer and a second layer, each of which has a different degree of diffusion of a constituent element between the first electrode and the second electrode.

The method of manufacturing a capacitor according to the present invention is for manufacturing a capacitor in which an electrode is connected to a dielectric film, and includes a first layer and a first layer which differ in the degree of diffusion of constituent elements between the first layer and the dielectric film. The method includes a step of forming an electrode having the second layer, and a step of forming a dielectric film by connecting to the electrode having the first layer and the second layer.

A method of manufacturing a memory according to the present invention is for manufacturing a memory having a capacitor in which an electrode is connected to a dielectric film, wherein the degree of diffusion of constituent elements differs from that of the dielectric film. Forming a capacitor electrode including the first layer and the second layer, and forming a dielectric film of the capacitor by connecting to the electrode including the first layer and the second layer. It is a thing.

[0013] In the electrode according to the present invention, the degree of diffusion between the electrode connecting portion and the first layer is different between the first layer and the second layer.

In the capacitor according to the present invention, when a voltage is applied between the pair of electrodes, polarization occurs in the dielectric film or charges are accumulated. Here, since at least one of the electrodes includes the first layer and the second layer having different degrees of diffusion between the electrode connection portion and the electrode connection portion, the dielectric film has high crystallinity. Even when the dielectric film is made thin, the capacitor shows excellent characteristics.

In the memory according to the present invention, when a voltage is applied between the pair of electrodes of the capacitor, polarization occurs or electric charges are accumulated in the dielectric film, whereby data is stored and read. Here, at least one of the electrodes of the capacitor includes the first layer and the second layer having different degrees of diffusion between the electrode connection portion, and thus the dielectric film has high crystallinity. Therefore, the memory has high performance even when the dielectric film is thinned.

In the method for manufacturing an electrode according to the present invention, a first layer and a second layer having different degrees of diffusion of constituent elements between the electrode connection portion and the electrode connection portion are formed.

In the method for manufacturing a capacitor according to the present invention,
An electrode including a first layer and a second layer having different degrees of diffusion of constituent elements between the dielectric film and the dielectric film is formed, and the dielectric film is formed by being connected to the electrode.

In the method for manufacturing a memory according to the present invention, an electrode including a first layer and a second layer having different degrees of diffusion of constituent elements between the electrode and the dielectric film is formed, and is connected to the electrode. As a result, the capacitor is formed.

[0019]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a configuration of a capacitor having electrodes according to an embodiment of the present invention. This capacitor 10 is formed on a substrate 11 made of, for example, silicon.
For example, if necessary, titanium (Ti) or titanium nitride (T
iN) and the like, and the lower electrode 1
3. The dielectric film 14 and the upper electrode 15 are sequentially laminated. That is, the capacitor 10 is formed by connecting a pair of electrodes (the lower electrode 13 and the upper electrode 15) to the dielectric film 14 which is the electrode connection portion.

The lower electrode 13 is formed of a first layer 1 which is different from that of the dielectric film 14 in that constituent elements are mutually diffused.
3a and a second layer 13b. First layer 13a
Are for preventing the constituent elements from diffusing with the dielectric film 14, and the diffusion of these elements is unlikely to occur. For example, the first layer 13a is composed of oxygen and at least one of a group consisting of iridium (Ir), platinum (Pt), and ruthenium (Ru). The oxygen content is 10% or more in atomic%.
It is preferable that it is within the range of 0% or less. This is because if the oxygen content is small, the particle diameter does not become too small, and the diffusion of the constituent elements cannot be effectively prevented. Also,
This is because if the oxygen content is large, the resistance value becomes too high. Note that the thickness of the first layer 13a is, for example, 100 nm.

The second layer 13b is formed between the first layer 13a and the dielectric film 14, and is used to make the crystal grow well when the dielectric film 14 is formed. It is. The second layer 13b is different from the first layer 13a in that, for example, at least one of a group consisting of iridium, platinum, and ruthenium so that constituent elements slightly diffuse with the dielectric film 14. Or at least one of them and oxygen. Second
When oxygen is contained in the layer 13b, its content is preferably less than 10% in atomic%. This is because if the oxygen content is large, diffusion of the constituent elements is unlikely to occur. The thickness of the second layer 13b is preferably in the range from 3 nm to 100 nm, and preferably from 5 nm to 50 nm.
It is more preferable if it is within the following range. If the thickness of the second layer 13b is small, the effect of assisting the crystal growth of the dielectric film 14 due to the diffusion of the constituent elements cannot be expected. If the thickness is large, a deteriorated layer is formed due to the diffusion of the constituent elements. Is to be reduced.

The dielectric film 14 contains an appropriate ferroelectric or high dielectric. These ferroelectric or high dielectric substances may be single crystal or polycrystal. As a ferroelectric,
For example, bismuth (Bi) and calcium (Ca), barium (Ba), strontium,
At least one member of the group consisting of lead (Pb) and bismuth and at least one member of the group consisting of iron (Fe), titanium, niobium (Nb), tantalum (Ta) and tungsten as the second element And a layered crystal structure oxide composed of oxygen and an oxide composed of oxygen and at least one of lead, zirconium (Zr) and titanium, and oxygen are preferable.

In particular, in this layered crystal structure oxide, bismuth, at least one of the group consisting of strontium, calcium and barium as the first element, and titanium, tantalum and niobium as the second element At least one of the group consisting of:
The composition formula is Bi _x (Sr, Ca, Ba) _y (Ti, Ta,
Nb) ₂ O ₉ ± _d (where 1.70 ≦ x ≦ 2.50,
0.60 ≦ y ≦ 1.20, 0 ≦ d ≦ 1.00). The crystal structure of this layered crystal structure oxide can be described in terms of stoichiometric composition as [Bi ₂ O
₂ ] ²⁺ and [(Sr, Ca, Ba) ₁ (T
i, Ta, Nb) ₂ O ₇ ] ^2- are alternately stacked.

Examples of the high dielectric substance include group IIa elements magnesium (Mg), calcium, strontium and barium, group IVa element titanium and zirconium, group Va element niobium and tantalum, and group IVb element lead and tin. An oxide comprising two or more elements selected from the group consisting of (Sn) and bismuth of a Vb group element, and oxygen is preferable because it has excellent characteristics. In particular, in this oxide, at least one first element A selected from the group consisting of group IIa elements magnesium, calcium, strontium and barium and group IVb element lead, and group IVa element titanium and zirconium And IV
It comprises at least one kind of second element B selected from the group consisting of group b element tin and oxygen, and has a composition formula of ABO ₃
Is preferably represented by The basic crystal structure of this oxide is a perovskite structure. Most preferred is an oxide composed of at least one of strontium and barium as the first element A, titanium as the second element B, and oxygen.

The upper electrode 15 is made of, for example, one of platinum, iridium, ruthenium, rhodium (Rh) or palladium (Pd), an alloy containing two or more of these, or at least one of these and oxygen and And an oxide containing

In this capacitor 10, the lower electrode 13, the dielectric film 14, and the upper electrode 15 may be formed in a plate shape as shown in FIG. 1, but as shown in FIG. The electrode 13 may have a protruding shape, and the dielectric film 14 and the upper electrode 15 may each have a curved shape so as to cover the same. With this configuration, the capacitor 1
Since the area of the dielectric film 14 can be increased without increasing the overall size of the capacitor 0, the size of the capacitor 10 can be reduced, which is preferable. In this case, the lower electrode 13 is formed such that the protruding first layer 13a has a curved second layer 13a.
Is preferably configured to be covered by the layer 13b. Thereby, the lower electrode 13 is in contact with the dielectric film 14 and the second
This is because a good crystal can be grown in the dielectric film 14 by making contact with the layer 13b.

The capacitor 10 having such a structure operates as follows.

In this capacitor 10, when a voltage is applied between the upper electrode 15 and the lower electrode 13, the dielectric film 1
At 4, polarization occurs or charge is stored. Here, the dielectric film 14 is the second layer 13 b of the lower electrode 13.
, The dielectric film 14 has high crystallinity, and the capacitor 10 exhibits excellent characteristics.

Such a capacitor 10 can be manufactured as follows.

First, a substrate 11 made of, for example, silicon is prepared, and an appropriate bonding layer 12 is formed on one side of the substrate 11 by, for example, a sputtering method.
3a and the second layer 13b are sequentially formed to form the lower electrode 13 (lower electrode forming step). In the formation of the lower electrode 13, for example, both the first layer 13a and the second layer 13b may be formed by a sputtering method (first layer forming step, second layer forming step). At this time, when the first layer 13a and the second layer 13b are composed of at least one of the group consisting of iridium, platinum and ruthenium and oxygen (that is, when they contain oxygen), for example, Reactive sputtering is performed using an inert gas such as an argon (Ar) gas and an oxygen gas. When the second layer 13b is made of at least one of the group consisting of iridium, platinum, and ruthenium (that is, when the second layer 13b does not contain oxygen), for example, an impurity such as argon gas is used. Sputtering is performed using an active gas.

When the lower electrode 13 is formed, for example, after forming the first layer 13a by a reactive sputtering method (first layer forming step), the lower layer 13 is formed in a reducing atmosphere such as a nitrogen atmosphere. The second layer may be formed on the surface of the first layer 13a by heating in the range of 300 ° C. or more and 800 ° C. or less (second layer forming step). For example, after forming the first layer 13a made of at least one member selected from the group consisting of iridium, platinum and ruthenium and oxygen, the first layer 13a is heated in a reducing atmosphere to form the first layer 13a.
3a, a second layer 13 made of at least one selected from the group consisting of iridium, platinum and ruthenium
b or a second layer 13b having a lower oxygen content than the first layer 13a is formed. Further, the lower electrode 13
When forming the first layer 13 a and the second layer 13 a, for example,
Layer 13b together with CVD (Chemical Vapor Deposition:
Chemical vapor deposition).

As described above, this method is preferable because the second layer 13b can be easily formed only by heating in a reducing atmosphere. In addition, the first layer 13a having a high oxygen content is easier to etch than the second layer 13b containing no oxygen or having a low oxygen content. The second layer 13b can be formed by forming the layer 13a of the lower electrode 13 in the shape of the lower electrode 13, and the lower electrode 13 can be easily processed, which is preferable.

Next, the surface of the lower electrode 13 (that is, the surface of the second layer 13b) is, for example, MOCVD (Meta
l Organic Chemical Vapor Deposition method, laser ablation method, sol-gel method, MOD (Metal Orga
The dielectric film 14 made of the layered crystal structure oxide or the oxide described above is formed by a nic decomposition method or a sputtering method (dielectric film forming step). At this time, since the dielectric film 14 is formed on the surface of the second layer 13b, constituent elements slightly diffuse at the interface between the second layer 13b and the dielectric film 14 during heating, and Crystal growth in the film 14 is assisted, and good crystals grow.

Subsequently, an appropriate upper electrode 15 is formed on the surface of the dielectric film 14 by a sputtering method (upper electrode forming step). After the upper electrode 15 is formed, the crystallinity of the dielectric film 14 may be improved by heating in an oxygen atmosphere as necessary. After that, for example, the capacitor 1 shown in FIG.
0 is formed.

The capacitor 10 shown in FIG.
Is formed, first, the bonding layer 12 is formed on one surface side of the substrate 11, and then the first layer 13a is formed on the surface in the same manner as described above. Next, the first layer 13a and the bonding layer 12 are selectively etched into a predetermined shape by, for example, ion milling. Subsequently, the second layer 13b is formed on the surface in the same manner as described above.
Here, if the second layer 13b is formed by heating in a reducing atmosphere, the step of processing the second layer 13b by etching can be eliminated.
preferable. After forming the second layer 13b, a dielectric film 14 is formed on the surface thereof in the same manner as described above. Here, it is preferable to form by a chemical vapor deposition method such as an MOCVD method or a laser ablation method. This is because a uniform film can be formed even on a surface having irregularities, so that the thickness of the dielectric film 14 can be made uniform. After that, the upper electrode 15 is formed in the same manner as described above, and the capacitor 10 shown in FIG. 2 is formed by performing appropriate etching.

As described above, the lower electrode 1 according to the present embodiment
According to 3 and the capacitor 10, since the first layer 13a and the second layer 13b are provided, it is possible to prevent the formation of a deteriorated layer due to the diffusion of constituent elements between the lower electrode 13 and the dielectric film 14. At the same time, by slightly diffusing constituent elements at the interface, the growth of crystals in the dielectric film 14 is assisted, and excellent crystals can be grown. Therefore, the characteristics of the capacitor 10 can be improved.

According to the method of manufacturing lower electrode 13 and the method of manufacturing capacitor 10 according to the present embodiment, first layer 13a and second layer 13 are formed by sputtering or the like.
Since b is formed, lower electrode 13 and capacitor 10 according to the present embodiment can be easily formed.

If the second layer 13b is formed by heating in a reducing atmosphere after forming the first layer 13a, the second layer 13b can be formed more easily. The lower electrode 13 can be easily etched.

Further, the capacitor 10 according to the present embodiment
According to the manufacturing method described above, since the dielectric film 14 is formed on the surface of the second layer 13b of the lower electrode 13, the structure at the interface between the second layer 13b and the dielectric film 14 during heating By slightly diffusing the elements, crystal growth can be assisted, and the crystallinity of the dielectric film 14 can be improved.

In addition, if the dielectric film 14 is formed by a chemical vapor deposition method, the curved dielectric film 14 can be formed.
Even if it is, it can be formed with a uniform film thickness. Therefore, the size of the capacitor 10 can be reduced.

The capacitor 10 is used, for example, as a part of a memory as follows.

FIG. 3 shows an example of a specific structure of a memory using a capacitor. This memory includes the capacitor 10 according to the present embodiment and a switching transistor 20. Transistor 2
Numeral 0 has a source region 21 made of an n ⁺ layer and a drain region 22 made of an n ⁺ layer formed at intervals on the surface of a substrate 11 made of, for example, p-type silicon. On the surface of the substrate 11 between the source region 21 and the drain region 22, LDD regions 23 and 24 made of n ⁻ layers formed at intervals are formed with the source region 21 and the drain region 22.
Are formed adjacent to each other. Source area 21
A gate electrode 2 as a word line is formed on the surface of the substrate 11 between
6 are formed. A gate side wall 27 made of an insulating material is formed on a side surface of the gate electrode 26. In addition,
A field oxide film 31 for element isolation is formed on the surface of the substrate 11 around the transistor 20.

An interlayer insulating film 3 is formed on the transistor 20.
2, a capacitor 10 is formed. That is, the bonding layer 12 and the lower electrode 1 are interposed via the interlayer insulating film 32.
3. The dielectric film 14 and the upper electrode 15 are sequentially laminated. Source region 21 of transistor 20 and lower electrode 13 (specifically, first layer 13 a) of capacitor 10 are electrically connected via contact hole 32 a provided in bonding layer 12 and interlayer insulating film 32. ing.
A plug layer 33 made of polycrystalline silicon, tungsten, or the like is buried in the contact hole 32a.
Note that an insulating film 34 is formed on the capacitor 10.

This memory uses the dielectric film 1 shown in FIG. 1 as the capacitor 10 according to this embodiment in FIG.
4 has a plate shape, but as shown in FIG. 4, the dielectric film 14 shown in FIG. 2 may have a curved shape.

In the memory having such a configuration, when a voltage is applied to the gate electrode 26 of the transistor 20,
The switch of the transistor 20 is turned “on”, and current flows between the source region 21 and the drain region 22. As a result, a current flows through the capacitor 10 via the plug layer 33, and a voltage is applied between the upper electrode 15 and the lower electrode 13. In the capacitor 10, when a voltage is applied, polarization occurs in the dielectric film 14 or charge is accumulated. As a result, storage or reading of data "1" or "0" is performed. Here, since the dielectric film 14 is formed on the surface of the second layer 13b of the lower electrode 13 in the capacitor 10, the dielectric film 14 has high crystallinity, and the capacitor 10 has excellent characteristics. Show. Therefore, the memory also has high performance.

This memory can be manufactured as follows. First, after the transistor 20 is formed on a suitable surface of the substrate 11 by a suitable method, an interlayer insulating film 32 is formed thereon by a CVD method or the like. Next, the interlayer insulating film 32 is selectively etched to form a contact hole 32a, exposing the source region 21 of the transistor 20. Subsequently, the plug layer 33 is buried in the contact hole 32a, and the plug layer 33 is connected to the source region 21. After that, the plug layer 33
The bonding layer 12, the lower electrode 13, the dielectric film 14, and the upper electrode are formed on the
Is connected to the plug layer 33 via the bonding layer 12. After forming the capacitor 10 in this manner, an insulating film 34 is formed thereon by a CVD method or the like. Thereby, the memory shown in FIG. 3 or FIG. 4 is formed.

As described above, according to this memory, since the lower electrode 13 and the capacitor 10 according to the present embodiment are provided, the same effects as those of the lower electrode 13 and the capacitor 10 according to the present embodiment can be obtained. Since the first layer 13a of the capacitor 10 is connected to the source region 21 of the transistor 20 via the plug layer 33, diffusion of constituent elements between the plug layer 33 and the lower electrode 13 can be prevented, Good electrical connection can be ensured.

According to the method of manufacturing the memory, the method of manufacturing the lower electrode 13 and the method of manufacturing the capacitor 10 according to the present embodiment are included. On the first layer 13
a, the capacitor 10 is formed by connecting the lower electrode 13 and the plug layer 3 by heating during the manufacturing process.
3 can be prevented from being diffused, and this memory can be realized.

[0050]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Further, specific embodiments of the present invention will be described in detail with reference to the drawings.

(First Embodiment) This embodiment will be described with reference to FIG. First, a substrate 11 made of silicon was prepared, and a 30-nm-thick bonding layer 12 made of Ti (titanium) was formed thereon by a sputtering method. continue,
A first layer 13a made of platinum oxide containing 15% by atomic% of oxygen was formed to a thickness of 100 nm on the bonding layer 12 by a reactive sputtering method using oxygen gas. Next, a second layer 13b made of platinum was formed thereon with a thickness of 20 nm by a sputtering method.

Subsequently, a dielectric film having a thickness of 100 nm is formed on the second layer 13b by a layered crystal structure oxide composed of bismuth, strontium, tantalum and oxygen and containing bismuth in excess of the stoichiometric composition. 14 was formed. The MOCVD method was used to form the dielectric film 14.

FIG. 5 shows the MOCVD used in this embodiment.
1 shows a schematic configuration of an apparatus. The MOCVD apparatus includes a liquid material supply device 40 for supplying a liquid organometallic precursor (organic metal material) as a gas, and an organic metal precursor vaporized by the liquid material supply device 40 to oxygen gas (O ₂ ). A gas mixing section 50 to be mixed and a reaction chamber 60 for reacting and thermally decomposing the gas mixed by the gas mixing section 50 to form a thin film on the substrate 11 are provided.

The liquid raw material supply device 40 has a plurality of containers 41 for accommodating a plurality of organometallic precursors, which are raw materials of a thin film to be formed, in a liquid state. Each container 41
Are connected to the liquid mixing valves 43 via the respective on-off valves 42 so that the respective organometallic precursors are mixed at a predetermined ratio. A vaporizing chamber 45 is connected to the liquid mixing valve 43 via a liquid pump 44.

The gas mixing section 50 mixes the organometallic precursor supplied together with the carrier gas (here, argon (Ar) gas) from the vaporization chamber 45 with the oxygen gas and supplies the mixture into the reaction chamber 60. I have. In the reaction chamber 60, a shower nozzle 61 connected to the gas mixing section 50 and a mounting table 62 are provided so as to face the shower nozzle 61. The mounting table 62 is provided with a heater (not shown) so that the substrate 11 can be heated to a predetermined temperature. In the reaction chamber 60, a pump 63 for evacuating the inside of the reaction chamber 60 is provided.

The raw material of bismuth is triphenylbismuth (Bi (C ₆ H ₅ ) ₃ ), and the raw material of strontium is di-2,2,6,6-tetramethyl-
3,5-heptandion strontium (Sr (C ₁₁ H
₁₉ O ₂ ) ₂ ) with tetraglyme (CH ₃ OCH ₂ CH ₂ O)
The compound to which CH ₃ ) has been added is, as a raw material of tantalum, tetra-isopropoxy-2,2,6,6-tetramethyl-3,5-heptanedione tantalum (Ta (O-
iC ₃ H ₇ ) ₄ (C ₁₁ H ₁₉ O ₂ )) was used.

Here, using such a MOCVD apparatus and raw materials, first, each opening / closing valve 42 is appropriately opened / closed, and each organometallic precursor is mixed in a liquid mixing valve 43 at a predetermined ratio. The gas was supplied to the gas mixing section 50 at a gas flow rate of 1000 SCCM including the carrier gas. Next, this raw material gas was mixed with oxygen gas of 1000 SCCM in the gas mixing section 50 and supplied to the reaction chamber 60 to form an amorphous layer made of bismuth, strontium, tantalum and oxygen on the surface of the second layer 13b. . At this time, the substrate 11 is heated to
Heating was performed within a range of 0 ° C. or less. Thereafter, the amorphous layer was crystallized by heating at 750 ° C. for 60 minutes in an oxygen atmosphere to form a dielectric film 14.

After the dielectric film 14 is formed in this manner, an upper electrode 15 made of platinum oxide containing 15% oxygen by atomic% is formed thereon by a reactive sputtering method using oxygen gas. It was formed thick. After forming the upper electrode 15, the crystallinity of the dielectric film 14 was improved by heating at 750 ° C. for 30 minutes in an oxygen atmosphere.
Thereafter, the upper electrode 15, the dielectric film 14, and the lower electrode 13 were selectively etched by ion milling to form the capacitor 10.

After forming an insulating film made of silicon oxide (SiO ₂ ) with a thickness of 300 nm on the capacitor 10, a contact hole is formed in the insulating layer by etching, and the insulating film is formed at 600 ° C. in an oxygen atmosphere. 30
Heated for minutes. After that, an extraction electrode is formed, and the ferroelectric characteristics of the capacitor 10 (dielectric polarization values of 2 Pr and 250
(leakage current when an electric field of kV / cm was applied) was measured. As a result, the dielectric polarization value 2Pr is 18.0 μC / c.
m ² , and the leak current was 1 × 10 ⁻⁸ A / cm ² . Incidentally, in the conventional capacitor in which the second layer 13b is not formed, when the film thickness of the dielectric film 14 is about 100 nm, the crystallinity is poor, so that the leakage current is large and the hysteresis cannot be measured. That is, according to the present example, sufficient characteristics were obtained even when the thickness of the dielectric film 14 was reduced, and it was found that the dielectric film 14 had excellent crystallinity.

(Second Embodiment) In this embodiment as well, FIG.
This will be described with reference to FIG. First, a substrate 11 made of silicon
Was prepared, and a titanium silicide (TiSi) film, a titanium nitride film, and a titanium film were sequentially deposited thereon by a sputtering method to form a bonding layer 12. Next, on top of that, by a reactive sputtering method using oxygen gas,
First iridium oxide containing 20% atomic% of oxygen
Was formed to a thickness of 100 nm. Subsequently, a second layer 13b made of platinum was formed thereon with a thickness of 20 nm by a sputtering method.

After forming the second layer 13b, a dielectric film 14 made of the same layered crystal structure oxide as that of the first embodiment was formed thereon to a thickness of 100 nm. Here, an amorphous layer is formed by the MOCVD method in the same manner as in the first embodiment, and then the amorphous layer is formed in an oxygen atmosphere.
RTA (Rapid Thermal Anneal) by heating at 0 ° C for 30 seconds
ing) treatment and heating at 750 ° C. for 30 minutes in an oxygen atmosphere to crystallize the amorphous layer.

After the dielectric film 14 is formed in this manner, an upper electrode 15 made of iridium oxide containing 20% by atomic% of oxygen is formed thereon by a reactive sputtering method using an oxygen gas. It was formed thick. After forming the upper electrode 15, the upper electrode 15 is formed in an oxygen atmosphere.
By heating at 0 ° C. for 30 minutes, the crystallinity of the dielectric film 14 was improved. Thereafter, the upper electrode 15, the dielectric film 14, and the lower electrode 13 were selectively etched by ion milling to form the capacitor 10.

After an insulating film made of tantalum oxide is formed on the capacitor 10 to a thickness of 50 nm,
A contact hole was formed in the insulating film by etching, and heated at 600 ° C. for 30 minutes in an oxygen atmosphere. After that, a lead electrode is formed and the capacitor 1
0 ferroelectric properties (dielectric polarization value 2 Pr and 250 kV / cm
(Leakage current when the electric field was applied) was measured. As a result, the dielectric polarization value 2Pr was 18.0 μC / cm ² , and the leak current was 1 × 10 ⁻⁸ A / cm ^2, which was the same result as in the first embodiment. That is, it was found that sufficient characteristics were obtained also in this example, and that the dielectric film 14 had excellent crystallinity.

(Third Embodiment) This embodiment will be described with reference to FIG. First, a substrate 11 made of silicon was prepared, and a titanium silicide film and a titanium nitride film were sequentially deposited thereon by a sputtering method to form a bonding layer 12. Next, a first layer 13a of iridium oxide containing 30% by atomic% of oxygen was formed with a thickness of 100 nm thereon by a reactive sputtering method using oxygen gas. Subsequently, the first layer 13a and the bonding layer 12 were each etched by ion milling to be processed into a protruding shape. After that, a second layer 13b made of an alloy of iridium and platinum was formed with a thickness of 10 nm on the surface by a sputtering method.

After forming the second layer 13b, a dielectric film 14 made of the same layered crystal structure oxide as that of the first embodiment was formed thereon to a thickness of 100 nm. Here, an amorphous layer is formed by the MOCVD method in the same manner as in the first embodiment, and then the amorphous layer is formed in an oxygen atmosphere.
RTA treatment was performed by heating at 0 ° C. for 30 seconds, and further heating at 750 ° C. for 1 hour in an oxygen atmosphere to crystallize the amorphous layer.

After the dielectric film 14 is formed in this manner, 40% of platinum, 40% of iridium and 40% of iridium are contained on the dielectric film 14 by a reactive sputtering method using oxygen gas. The upper electrode 15 made of an oxide containing 20% by atomic% was formed with a thickness of 100 nm. After forming the upper electrode 15, the upper electrode 15 is formed in an oxygen atmosphere.
By heating at 0 ° C. for 30 minutes, the crystallinity of the dielectric film 14 was improved. After that, the upper electrode 15 and the dielectric film 14 were selectively etched by ion milling to form the capacitor 10.

After forming an insulating film made of silicon dioxide (SiO ₂ ) with a thickness of 300 nm on the capacitor 10, a contact hole is formed in the insulating film by etching, and at 600 ° C. in an oxygen atmosphere. 3
Heated for 0 minutes. After that, the extraction electrode is formed,
Ferroelectric characteristics of the capacitor 10 (dielectric polarization values 2Pr and 25
(Leakage current when an electric field of 0 kV / cm was applied) was measured. As a result, the dielectric polarization value 2Pr was 18.0 μC /
cm ² , and the leak current was 1 × 10 ⁻⁸ A / cm ^2, which was the same as that of the first embodiment. That is, it was found that sufficient characteristics were obtained also in this example, and that the dielectric film 14 had excellent crystallinity.

(Fourth Embodiment) This embodiment will be described with reference to FIG. First, a substrate 11 made of silicon was prepared, and a titanium silicide film, a titanium nitride film, and a titanium film were sequentially deposited thereon by a sputtering method to form a bonding layer 12. Next, oxygen was added thereon in an amount of 20 atomic% by a reactive sputtering method using oxygen gas.
% Of the first layer 13a made of iridium oxide containing 100%.
It was formed with a thickness of nm. Subsequently, a second layer 13b made of iridium is formed thereon by a sputtering method.
It was formed with a thickness of nm.

After forming the second layer 13b, a dielectric film 14 having a thickness of 80 nm is formed thereon by an oxide composed of lead, zinc, titanium and oxygen and containing more lead than the stoichiometric composition. Was formed. This dielectric film 14 was formed by MOCVD in the same manner as in the first embodiment. In addition,
Di-2,2,6,6-tetramethyl-
3,5-heptanedione lead _{(Pb (C 11 H 19 O} 2) 2)
, And zinc di-2,2,6,6-tetramethyl-3,5-heptanedione (Zn (C ₁₁ H ₁₉ O)
_{2) 2),} as a raw material of titanium di - isopropoxy - di-2,2,6,6-tetramethyl-3,5-heptane dione titanium _{(Ti (O-iC 3 H} 7) 2 (C 11 H ₁₉
O ₂ ) ₂ ) were used. After this, an amorphous layer is formed.
The amorphous layer was crystallized by heating for 0 minutes.

After the dielectric film 14 is formed in this manner, an upper electrode 15 made of iridium oxide containing 20% of atomic% of oxygen is formed thereon by a reactive sputtering method using oxygen gas. It was formed thick. After the upper electrode 15 is formed, the upper electrode
By heating at 0 ° C. for 10 minutes, the crystallinity of the dielectric film 14 was improved. Thereafter, the upper electrode 15, the dielectric film 14, and the lower electrode 13 were selectively etched by ion milling to form the capacitor 10.

An insulating film made of titanium oxide (TiO ₂ ) having a thickness of 10 nm is formed on the capacitor 10, and an insulating film made of silicon dioxide (SiO ₂ ) is formed on the insulating film having a thickness of 300 nm.
After forming each with a film thickness of nm, a contact hole was formed in this insulating film by etching and heated at 500 ° C. for 30 minutes in an oxygen atmosphere. After that, an extraction electrode was formed, and the ferroelectric characteristics (leakage current when a dielectric polarization value of 2 Pr and an electric field of 250 kV / cm were applied) of the capacitor 10 were measured. As a result, the dielectric polarization value 2
Pr is 18.0 μC / cm ² , and leak current is 1 × 10 ^−7.
A good result of A / cm ² was obtained. That is, it was found that sufficient characteristics were obtained also in this example, and that the dielectric film 14 had excellent crystallinity.

(Fifth Embodiment) In this embodiment as well, FIG.
This will be described with reference to FIG. First, a substrate 11 made of silicon
And a titanium silicide film and a titanium nitride film are sequentially deposited thereon by sputtering to form a bonding layer 12.
Was formed. Next, a first layer 13a of iridium oxide containing 20% of atomic% of oxygen was formed with a thickness of 50 nm thereon by a reactive sputtering method using oxygen gas. Subsequently, a second layer 13b made of ruthenium was formed thereon with a thickness of 5 nm by a sputtering method.

After the formation of the second layer 13b, a dielectric film 14 having a thickness of 80 nm was formed on the second layer 13b using an oxide composed of barium, strontium, titanium and oxygen. This dielectric film 14 was formed by MOCVD in the same manner as in the first embodiment. In addition, as a raw material of barium, di-2,2,6,6-tetramethyl-3,5-heptanedione barium (Ba (C ₁₁ H ₁₉ O ₂ ) ₂ ) was used.
Di-2,2,6,6-tetramethyl-3,5-heptandion strontium (Sr (C ₁₁ H ₁₉ O ₂ ) ₂ ) is used as a raw material of strontium, and di-isopropoxydi is used as a raw material of titanium. −2,2,6,6-tetramethyl-3,5-heptanedione titanium (Ti (O-iC ₃
H ₇ ) ₂ (C ₁₁ H ₁₉ O ₂ ) ₂ ) was used. Further, the heating temperature of the substrate 11 was in the range of 400 ° C. or more and 700 ° C. or less. After the formation of the amorphous layer, the amorphous layer was crystallized by heating at 650 ° C. for 30 minutes in an oxygen atmosphere.

After the dielectric film 14 was formed in this manner, an upper electrode 15 made of ruthenium was formed thereon with a thickness of 100 nm by a sputtering method. After the upper electrode 15 is formed,
Heat at 0 ° C. for 30 minutes. Thereafter, the upper electrode 15, the dielectric film 14, and the lower electrode 13 were selectively etched by ion milling to form the capacitor 10.

After an insulating film made of silicon dioxide (SiO ₂ ) having a thickness of 300 nm is formed on the capacitor 10, a contact hole is formed in the insulating film by etching, and the film is placed in a nitrogen atmosphere at 600 ° C. for 30 minutes. After heating, an extraction electrode was formed, and the characteristics of the capacitor 10 (current-voltage characteristics and leakage current when an electric field of 250 kV / cm was applied) were measured. as a result,
Good current-voltage characteristics are obtained, and leakage current is 2 × 10
A good result of ^-8 A / cm ² was obtained. That is, it was found that sufficient characteristics were obtained also in this example, and that the dielectric film 14 had excellent crystallinity.

(Sixth Embodiment) This embodiment will be described with reference to FIG. First, a substrate 11 made of silicon was prepared, and a titanium silicide film and a titanium nitride film were sequentially deposited thereon by a sputtering method to form a bonding layer 12. Next, a first layer 13a of iridium oxide (IrO ₂ ) was formed thereon to a thickness of 200 nm by a reactive sputtering method using oxygen gas. Subsequently, the first layer 13a and the bonding layer 12 were each etched by ion milling to be processed into a protruding shape. After that, the substrate was heated at 700 ° C. for 30 minutes in a nitrogen atmosphere, so that the surface of the first layer 13 a was formed into a second layer 13 b of iridium with a thickness of 10 nm.

After the formation of the second layer 13b, a layered crystal structure oxide comprising bismuth, strontium, tantalum, niobium and oxygen and containing bismuth in excess of the stoichiometric composition has a thickness of 100 nm. Was formed. This dielectric film 14 was formed by MOCVD in the same manner as in the first embodiment. In addition, as a raw material of niobium, tetra-isopropoxy-2,2,2
6,6-tetramethyl-3,5-heptane dione niobium _{(Nb (O-iC 3 H} 7) 4 (C 11 H 19 O 2)) was used. After forming an amorphous layer by this, RTA treatment was performed by heating at 750 ° C. for 30 seconds in an oxygen atmosphere, and further heating at 750 ° C. for 1 hour in an oxygen atmosphere to crystallize the amorphous layer.

After the dielectric film 14 is formed in this manner, 40% of platinum, 40% of iridium and 40% of iridium are contained thereon by a reactive sputtering method using an oxygen gas. The upper electrode 15 made of an oxide containing 20% by atomic% was formed with a thickness of 100 nm. After forming the upper electrode 15, the upper electrode 15 is formed in an oxygen atmosphere.
By heating at 0 ° C. for 30 minutes, the crystallinity of the dielectric film 14 was improved. After that, the upper electrode 15 and the dielectric film 14 were selectively etched by ion milling to form the capacitor 10.

After an insulating film made of tantalum oxide is formed on the capacitor 10 to a thickness of 50 nm,
A contact hole was formed in the insulating film by etching, and heated at 600 ° C. for 30 minutes in an oxygen atmosphere. After that, a lead electrode is formed and the capacitor 1
0 ferroelectric properties (dielectric polarization value 2 Pr and 250 kV / cm
(Leakage current when the electric field was applied) was measured. As a result, good results were obtained with a dielectric polarization value of 2Pr of 20.0 μC / cm ² and a leak current of 3 × 10 ⁻⁸ A / cm ² . That is, it was found that sufficient characteristics were obtained also in this example, and that the dielectric film 14 had excellent crystallinity.

(Seventh Embodiment) In this embodiment as well, FIG.
This will be described with reference to FIG. First, a substrate 11 made of silicon
And a titanium silicide film and a titanium nitride film are sequentially deposited thereon by sputtering to form a bonding layer 12.
Was formed. Next, iridium oxide (Ir) was formed thereon by a reactive sputtering method using oxygen gas.
A first layer 13a made of O ₂ ) was formed with a thickness of 100 nm. Subsequently, the first layer 13a and the bonding layer 1
Sample No. 2 was etched by ion milling, and processed into a protruding shape. After that, the surface is subjected to a reactive sputtering method using oxygen gas to make oxygen 5% by atomic%.
A second layer 13b of platinum oxide was formed to a thickness of 20 nm.

After forming the second layer 13b, a dielectric film 14 made of the same layered crystal structure oxide as that of the sixth embodiment was formed on the second layer 13b to a thickness of 100 nm. Here, after forming an amorphous layer by MOCVD in the same manner as in the first embodiment, the amorphous layer is formed in an oxygen atmosphere.
RTA treatment was performed by heating at 0 ° C. for 30 seconds, and further heating at 700 ° C. for 1 hour in an oxygen atmosphere to crystallize the amorphous layer.

After the dielectric film 14 is formed in this manner, an upper electrode 15 made of platinum oxide containing 5% of atomic% of oxygen is formed thereon by a reactive sputtering method using an oxygen gas. It was formed thick. Upper electrode 1
After the formation of 5, at 700 ° C. in an oxygen atmosphere, 3
By heating for 0 minutes, the crystallinity of the dielectric film 14 was improved. After that, the upper electrode 15 and the dielectric film 14 were selectively etched by ion milling to form the capacitor 10.

After forming an insulating film made of silicon dioxide to a thickness of 100 nm on the capacitor 10, a contact hole was formed in the insulating film by etching and heated at 600 ° C. for 30 minutes in an oxygen atmosphere. . After that, an extraction electrode is formed, and the ferroelectric characteristics of the capacitor 10 (dielectric polarization value 2 Pr and 250 kV / c
m when an electric field of m was applied. As a result, good results were obtained with a dielectric polarization value of 2Pr of 20.0 μC / cm ² and a leak current of 3 × 10 ⁻⁸ A / cm ² . That is, it was found that sufficient characteristics were obtained also in this example, and that the dielectric film 14 had excellent crystallinity.

(Eighth Embodiment) In this embodiment, FIG.
This will be described with reference to FIG. First, a substrate 11 made of silicon
And a titanium silicide film and a titanium nitride film are sequentially deposited thereon by sputtering to form a bonding layer 12.
Was formed. Next, ruthenium oxide (Ru) was formed thereon by a reactive sputtering method using oxygen gas.
A first layer 13a made of O ₂ ) was formed with a thickness of 100 nm. Subsequently, the first layer 13a and the bonding layer 1
Sample No. 2 was etched by ion milling, and processed into a protruding shape. After that, the surface is subjected to a reactive sputtering method using oxygen gas to make oxygen 5% by atomic%.
A second layer 13b of platinum oxide was formed to a thickness of 20 nm.

After forming the second layer 13b, a dielectric film 14 made of the same layered crystal structure oxide as that of the sixth embodiment was formed thereon to a thickness of 100 nm. Here, after forming an amorphous layer by MOCVD in the same manner as in the first embodiment, the amorphous layer is formed in an oxygen atmosphere.
RTA treatment was performed by heating at 0 ° C. for 30 seconds, and further heating at 700 ° C. for 1 hour in an oxygen atmosphere to crystallize the amorphous layer.

After the dielectric film 14 is formed in this manner, an upper electrode 15 made of platinum oxide containing 5% of atomic% of oxygen is formed thereon by a reactive sputtering method using an oxygen gas. It was formed thick. Upper electrode 1
After the formation of 5, at 600 ° C. in an oxygen atmosphere, 3
By heating for 0 minutes, the crystallinity of the dielectric film 14 was improved. After that, the upper electrode 15 and the dielectric film 14 were selectively etched by ion milling to form the capacitor 10.

After an insulating film made of silicon dioxide was formed to a thickness of 100 nm on the capacitor 10, a contact hole was formed in the insulating film by etching and heated at 600 ° C. for 30 minutes in an oxygen atmosphere. . After that, an extraction electrode is formed, and the ferroelectric characteristics of the capacitor 10 (dielectric polarization value 2 Pr and 250 kV / c
m when an electric field of m was applied. As a result, good results were obtained with a dielectric polarization value of 2Pr of 20.0 μC / cm ² and a leak current of 3 × 10 ⁻⁸ A / cm ² . That is, it was found that sufficient characteristics were obtained also in this example, and that the dielectric film 14 had excellent crystallinity.

In each of the embodiments described above, some specific examples have been described. However, with the capacitor 10 of the present invention, the same results as in the above embodiments can be obtained. That is, the first layer 13a is made of at least one member selected from the group consisting of iridium, platinum, and ruthenium and oxygen, and the oxygen content is set to 10% or more in atomic%, and Forming a layer 13b of at least one of the group consisting of iridium, platinum and ruthenium;
Alternatively, if the second layer 13b is composed of one kind thereof and oxygen and the content of oxygen is set to be less than 10% in atomic% and the thickness of the second layer 13b is set to 3 nm or more and 100 nm or less,
The crystallinity of the dielectric film 14 can be improved, and the dielectric film 1
Even if the thickness of No. 4 is reduced, good characteristics can be obtained.

Although the present invention has been described with reference to the embodiment and each example, the present invention is not limited to the embodiment and each example, and can be variously modified. For example, in the above-described embodiment and each example, only the case where the lower electrode 13 includes the first layer 13a and the second layer 13b has been described. And the second layer, and the upper electrode 15 in addition to the lower electrode 13 may include the first layer and the second layer.

Further, in the above-described embodiment and each example, only the case where the electrode connection portion is the dielectric film 14 has been described, but the electrode of the present invention is connected to various electrode connection portions. It can be applied when it is done. In particular, this is effective when a crystal is grown on the surface of the electrode to form the electrode connection portion.

Further, in the above embodiment, the substrate 1
Capacitor 10 and transistor 2 perpendicular to 1
Although the memory in which 0 is formed has been described, the present invention can also be applied to a memory in which a capacitor and a transistor are formed side by side in a direction parallel to a substrate.

In the above embodiment, the case where the capacitor 10 is used for one memory has been described. However, the present invention provides an LSI (Larg) in which a plurality of memories are integrated.
e Scale Integrated Circuit) The same applies to memories.

[0093]

As described above, according to the electrode of the present invention, the first layer and the second layer having different degrees of diffusion between the electrode connection portion are provided. The effect of preventing the formation of a degraded layer due to the diffusion of the constituent element between the electrode and the connected part of the electrode and the diffusion of the constituent element at the interface can assist, for example, the growth of the crystal at the connected part of the electrode. To play.

Further, according to the capacitor or the memory of the present invention, at least one electrode has the first layer and the second layer having different degrees of diffusion with the dielectric film. In addition to preventing the formation of a deteriorated layer due to the diffusion of the constituent elements between the electrode and the dielectric film,
The diffusion of the constituent elements at the interface assists the growth of crystals in the dielectric film, thereby improving the crystallinity of the dielectric film. Therefore, there is an effect that excellent characteristics can be obtained even when the thickness of the dielectric film is reduced.

Further, according to the method of manufacturing an electrode according to the present invention, the first layer and the second layer having different degrees of diffusion between the electrode connection portion are formed, respectively. The electrode of the present invention can be easily manufactured, and the electrode of the present invention can be easily realized.

According to the method for manufacturing a capacitor or the method for manufacturing a memory according to the present invention, an electrode including a first layer and a second layer having different degrees of diffusion between a dielectric film and a dielectric film is formed. Then, since a dielectric film is formed by connecting to the electrode, the formation of a degraded layer between the electrode and the dielectric film due to heating is prevented, and the constituent elements are slightly reduced at the interface between them. By diffusing, it is possible to assist the growth of crystals, and it is possible to improve the crystallinity of the dielectric film.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a capacitor including an electrode according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a modification of the electrode and the capacitor illustrated in FIG.

3 is a cross-sectional view illustrating a configuration of a memory using the capacitor illustrated in FIG.

4 is a cross-sectional view illustrating a configuration of a memory using the capacitor illustrated in FIG.

FIG. 5 is a configuration diagram illustrating a MOCVD apparatus used in an embodiment of the present invention.

[Explanation of symbols]

11: substrate, 12: bonding layer, 13: lower electrode, 13a ...
1st layer, 13b ... 2nd layer, 14 ... dielectric film, 15 ...
Upper electrode, 20: transistor, 21: source region, 2
2 ... drain region, 23, 24 ... LDD region, 25 ... gate oxide film, 26 ... gate electrode, 27 ... gate side wall, 3
DESCRIPTION OF SYMBOLS 1 ... Field oxide film, 32 ... Interlayer insulating film, 32a ... Contact hole, 33 ... Plug layer, 34 ... Insulating film, 40
... Liquid raw material supply device, 41 ... Container, 42 ... On-off valve, 43
... liquid mixing valve, 44 ... liquid pump, 45 ... vaporization chamber,
50: gas mixing section, 60: reaction chamber, 61: shower nozzle, 62: mounting table, 63: pump

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Chiharu Isobe 6-7-35 Kita Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation

Claims (33)

[Claims] 1. An electrode connected to an electrode-connected portion, comprising a first layer and a second layer having different degrees of diffusion of constituent elements between the electrode-connected portion. Electrode. 2. The first layer has a smaller degree of diffusion of a constituent element between the first layer and the electrode connection part than the second layer, and is connected to the electrode connection part via the second layer. The electrode according to claim 1, wherein: 3. The first layer comprises at least one member selected from the group consisting of iridium (Ir), platinum (Pt) and ruthenium (Ru) and oxygen (O), and contains 10% of oxygen by atomic%. 2. The electrode according to claim 1, wherein said second layer comprises at least one member selected from the group consisting of iridium, platinum and ruthenium. 4. The first layer comprises at least one member selected from the group consisting of iridium, platinum and ruthenium and oxygen and contains oxygen in an amount of 10% or more by atomic%, and the second layer comprises iridium, platinum and ruthenium. The electrode according to claim 1, comprising oxygen and at least one member of the group consisting of platinum and ruthenium, and containing less than 10% by atomic% of oxygen. 5. The second layer has a thickness of at least 3 nm and at least 10 nm.
2. The electrode according to claim 1, wherein the thickness is within a range of 0 nm or less. 6. The second layer has a thickness of not less than 5 nm and not more than 50 nm.
2. The electrode according to claim 1, wherein the diameter is within the range of nm or less. 7. A capacitor in which a pair of electrodes are respectively connected to a dielectric film, wherein at least one of the pair of electrodes has a different degree of diffusion of a constituent element between the first electrode and the dielectric film. And a second layer. 8. The first layer has a smaller degree of diffusion of constituent elements between the first layer and the dielectric film than the second layer, and is connected to the dielectric film via the second layer. The capacitor according to claim 7, wherein: 9. The first layer comprises at least one member selected from the group consisting of iridium, platinum and ruthenium and oxygen and contains oxygen in an amount of 10% or more by atomic%, and the second layer comprises iridium, platinum and ruthenium. The capacitor according to claim 7, comprising at least one member from the group consisting of platinum and ruthenium. 10. The first layer comprises at least one member selected from the group consisting of iridium, platinum and ruthenium and oxygen, and contains at least 10% by atom of oxygen.
8. The capacitor according to claim 7, wherein said second layer comprises at least one member selected from the group consisting of iridium, platinum and ruthenium and oxygen, and contains less than 10% of oxygen in atomic%. 11. The second layer has a thickness of 3 nm or more and 1
8. The structure according to claim 7, wherein the thickness is within a range of not more than 00 nm.
A capacitor as described. 12. The second layer has a thickness of not less than 5 nm and not more than 5 nm.
8. The capacitor according to claim 7, wherein the value is within a range of 0 nm or less. 13. The method according to claim 1, wherein the dielectric film is made of bismuth (Bi).
And at least one of the group consisting of calcium (Ca), barium (Ba), strontium (Sr), lead (Pb) and bismuth as a first element, and iron (Fe) as a second element , Titanium (Ti), niobium (N
8. The capacitor according to claim 7, comprising a layered crystal structure oxide composed of oxygen and at least one selected from the group consisting of b), tantalum (Ta) and tungsten (W). 14. The dielectric film is made of bismuth, at least one of a group consisting of strontium, calcium and barium as a first element, and a group consisting of titanium, tantalum and niobium as a second element. And a layered crystal structure oxide composed of oxygen, and the layered crystal structure oxide has a composition formula of Bi
_x (Sr, Ca, Ba) _y (Ti, Ta, Nb) ₂ O ₉
± _d (However, 1.70 ≦ x ≦ 2.50, 0.60 ≦ y ≦
8. The capacitor according to claim 7, wherein 1.20, 0 ≦ d ≦ 1.00). 15. The capacitor according to claim 7, wherein the dielectric film contains an oxide composed of lead, at least one of zirconium (Zr) and titanium, and oxygen. 16. The capacitor according to claim 7, wherein said dielectric film contains an oxide composed of at least one of barium and strontium, titanium, and oxygen. 17. A memory having a capacitor in which a pair of electrodes are respectively connected to a dielectric film, wherein the capacitor diffuses a constituent element between at least one of the pair of electrodes and the dielectric film. A memory comprising: a first layer and a second layer having different degrees of operation. 18. The first layer has a smaller degree of diffusion of constituent elements between itself and a dielectric film than the second layer, and is connected to the dielectric film via the second layer. The memory of claim 17, wherein: 19. The first layer comprises at least one member selected from the group consisting of iridium, platinum, and ruthenium and oxygen, and contains at least 10% by atomic% of oxygen.
The memory of claim 17, wherein the second layer comprises at least one of the group consisting of iridium, platinum, and ruthenium. 20. The first layer, comprising at least one member selected from the group consisting of iridium, platinum and ruthenium and oxygen, containing at least 10% by atomic% of oxygen,
18. The memory of claim 17, wherein said second layer comprises at least one member of the group consisting of iridium, platinum, and ruthenium and oxygen and contains less than 10 atomic percent oxygen. 21. The second layer has a thickness of not less than 3 nm and not more than 1 nm.
3. The thickness is within a range of not more than 00 nm.
0 described memory. 22. The second layer has a thickness of not less than 5 nm and not more than 5 nm.
21. The range of not more than 0 nm.
The described memory. 23. The memory according to claim 17, further comprising a transistor connected to said capacitor via a plug layer. 24. The memory according to claim 22, wherein the plug layer is made of silicon (Si) or tungsten (W). 25. A method of manufacturing an electrode to be connected to an electrode-connected portion, comprising: a first layer and a second layer having different degrees of diffusion of constituent elements between the electrode-connected portion. A method for manufacturing an electrode, comprising a step of forming each. 26. The method according to claim 24, wherein the first layer and the second layer are respectively formed by a sputtering method. 27. A step of forming a first layer, and heating the first layer in a reducing atmosphere.
26. The method according to claim 25, further comprising: forming a second layer on the surface of the first layer. 28. The method according to claim 28, wherein in the step of forming the first layer, a first layer made of oxygen and at least one member selected from the group consisting of iridium, platinum, and ruthenium is formed,
In the step of forming the second layer, a second layer made of at least one of a group consisting of iridium, platinum, and ruthenium or a second layer having a lower oxygen content than the first layer is formed. The method for manufacturing an electrode according to claim 27, wherein: 29. The method according to claim 27, wherein, in the step of forming the second layer, the first layer is heated in a nitrogen atmosphere within a range of 300 ° C. to 800 ° C. . 30. A method for manufacturing a capacitor in which an electrode is connected to a dielectric film, comprising: a first layer and a second layer having different degrees of diffusion of constituent elements between the dielectric film and the dielectric film. A method for manufacturing a capacitor, comprising: a step of forming an electrode; and a step of forming a dielectric film by connecting to an electrode including a first layer and a second layer. 31. The method according to claim 30, wherein in the step of forming the dielectric film, the dielectric film is formed by a chemical vapor deposition method. 32. A method for manufacturing a memory having a capacitor in which an electrode is connected to a dielectric film, comprising: a first layer and a second layer having different degrees of diffusion of constituent elements between the first layer and the second layer; Forming an electrode of a capacitor provided with a first layer and a step of forming a dielectric film of the capacitor by connecting to an electrode provided with a first layer and a second layer. Method. 33. A method of manufacturing a memory comprising a transistor connected to a capacitor via a plug layer, the method comprising: forming a transistor; forming a plug layer by connecting to the transistor; 33. The method according to claim 32, further comprising the step of connecting the electrodes to form a capacitor.