JPH11340435A - Manufacture of semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve surface morphology and to suppress island-shaped growth when forming a capacitor electrode. SOLUTION: In the manufacture of a capacitor using a metal oxide as a dielectric film 10 and using a ruthenium film or a ruthenium oxide film as electrodes 8 and 11 for sandwiching the dielectric film, at least one electrode is formed by the CVD method using an organic group ruthenocene where at least one hydrogen out of ruthenocene or cyclopentadienyl ring is substituted for an organic functional group as a feed gas. In that case, for promoting a reaction for decomposing the cyclopentadienyl ring for forming the framework of cyclopentadienyl ring that is the ligand of the feed gas or the cyclopentadienyl with an organic functional group into a group with one carbon and a group with four carbons, or a reaction for decomposing into a group with one carbon and a group with two carbons, a catalyst that is made of a substance containing at least an 8-group or an 1B-group element is formed on the underlying surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method of manufacturing a semiconductor device, and more particularly to the formation of ruthenium or ruthenium oxide used as an electrode of a capacitor.

[0002]

2. Description of the Related Art In recent years, as semiconductor integrated circuits have become more highly integrated, circuit miniaturization has been progressing, and the cell area of capacitors has also become extremely small. As the cell area decreases, the capacitance of the capacitor also decreases. However, there is a demand that the capacitance of the capacitor cannot be reduced so much in terms of sensitivity and soft error. As a method of solving this, a method of forming a capacitor three-dimensionally and increasing the cell area as much as possible to obtain a capacitor capacitance, and a method of using an insulating film having a high dielectric constant as a capacitor insulating film are being studied.

A typical insulating film having a high dielectric constant is (Ba, Sr) TiO ₃ , but when such an oxide dielectric is used, a low dielectric constant is formed at the interface between the electrode and the dielectric film. In order to prevent the formation of the insulating film, it is necessary to use a material which is not oxidized or which exhibits metal conductivity even if oxidized. In recent years, ruthenium (Ru), which exhibits metal conductivity even when oxidized, has been studied as an electrode material of a capacitor having such properties.

FIG. 1 shows an example of a method of forming a capacitor using Ru as an electrode and (Ba, Sr) TiO ₃ as an insulating film.
4 (a) to FIG. 15 (d). First, STI (Shallow) is formed on a p-type Si substrate 1.
After forming the element isolation region 2 by Trench Isolation, a gate insulating film 3a, a gate electrode (word line) 3b, and an n ⁺ diffusion layer 4 constituting the transistor are formed. After that, the interlayer insulating film 5a is deposited and flattened, and then the bit line 6 is formed. Subsequently, the interlayer insulating film 5b
After depositing and flattening, a contact hole is opened to bury the W film 7 and process (FIG. 14A).

Next, after depositing and planarizing the interlayer insulating film 5c, a contact hole is opened (FIG. 14B).
Next, the Ru film 8 is made of Ru (C ₅ H ₅ ) ₂ (cyclopentadienyl ruthenium (common name: ruthenocene);
₅ H ₅ ) is deposited by CVD using Cp, (C ₅ H ₅ ) ₂ is abbreviated as (Cp) ₂ ) and O _2, and then an SOG film 9 is applied on the entire surface, and furthermore, CMP (chemical The SOG film 9 and the Ru film 8 on the interlayer insulating film 5c are removed by a mechanical polishing method (FIG. 14C).

Further, a sufficiently diluted HF aqueous solution or H
After removing all the SOG film 9 by the F vapor, (Ba,
Sr) A TiO ₃ film 10 is deposited by a CVD method. afterwards,
A Ru film 11 is deposited by a CVD method and processed as an upper electrode (FIG. 15D).

In order to increase the capacitance of the capacitor, it is necessary to manufacture a three-dimensional capacitor, and a high dielectric constant (Ba,
Even if Sr) TiO ₃ is used, as described above, CVD
It is necessary to form an electrode and an oxide dielectric by a method.

However, in general, a metal film or a metal oxide film having metal conductivity formed by a CVD method has poor surface morphology, and when this is used as an electrode of a capacitor, leakage current increases due to electric field concentration. Also, if an attempt is made to form an ultra-thin electrode in order to realize miniaturization, the film will not be connected because of an island shape, and if this is used as a capacitor electrode, the capacitor area cannot be increased, and There is also a problem that the capacity required for the operation cannot be secured.

When a columnar capacitor is formed,
If the Ru film has poor surface morphology, a seam as shown in FIG. 16 is formed at the center of the Ru electrode 8 when the Ru film on the interlayer insulating film 5c is removed by the CMP method. For this reason, when the (Ba, Sr) TiO ₃ film as the capacitor insulating film is deposited, the capacitor insulating film in the seam portion is dented, and there is a problem that an increase in leak current due to electric field concentration occurs.

[0010]

As described above, since the oxide of Ru (ruthenium oxide: RuO ₂ ) also exhibits metal conductivity, the electrode material of a capacitor using (Ba, Sr) TiO ₃ or the like as a dielectric material is used. However, when formed by the CVD method, it is difficult to obtain good surface morphology, and there is a problem that Ru or RuO ₂ is formed in an island shape.

The present invention has been made to solve the above-mentioned conventional problems, and provides a manufacturing method which is excellent in surface morphology and can suppress island-like growth when forming ruthenium or ruthenium oxide serving as a capacitor electrode. The purpose is to do.

[0012]

According to the present invention, there is provided a method of manufacturing a semiconductor device having a capacitor using a metal oxide as a dielectric film and using a ruthenium film or a ruthenium oxide film as an electrode sandwiching the dielectric film. A step of forming at least one electrode by a CVD method using an organic group ruthenocene in which at least one hydrogen of a ruthenocene or cyclopentadienyl ring is substituted by an organic functional group as a source gas, using a ligand of the source gas. Reaction of decomposing a cyclopentadienyl ring forming a skeleton of a cyclopentadienyl group or a cyclopentadienyl group having an organic functional group into one carbon group and four carbon groups, or one carbon group And a condition for accelerating the reaction for decomposing into two groups of two carbons (claim 1).

As a treatment for accelerating the reaction for decomposing into a group of one carbon and four carbons or the reaction for decomposing into a group of one carbon and two groups of two carbons, the process of forming the electrode (Claim 2).

The catalyst formed on the underlayer surface includes a substance containing an element of at least the group 8 or 1B (simple element or compound of the element). The catalyst is 0.5
It preferably has a thickness or a particle size of at least nm. For example, a substance containing a Group 8 or 1B element is formed by a sputtering method, or is immersed in a solution containing a Group 8 or 1B element. It can be formed by a method.

Further, the present invention provides a method of manufacturing a semiconductor device having a capacitor using a metal oxide as a dielectric film and using a ruthenium film or a ruthenium oxide film as an electrode sandwiching the dielectric film. Is formed by a CVD method using, as a source gas, an organic group ruthenocene in which at least one hydrogen of a ruthenocene or cyclopentadienyl ring is substituted with an organic functional group. The method is characterized in that the reaction is performed under conditions that suppress a reaction in which a cyclopentadienyl ring forming a skeleton of a cyclopentadienyl group having an enyl group or an organic functional group is decomposed to form a ruthenium acetylide derivative. ).

The treatment for suppressing the reaction for producing the ruthenium acetylide derivative includes a surface treatment for a base on which the electrode is formed (Claim 5).
In particular, a surface treatment for causing a reaction for giving a negative charge to the constituents of the source gas (claim 6) can be mentioned. Specific surface treatments include exposure to plasma, immersion in a solution containing halogen ions, and immersion in an alkaline solution.

Further, when the invention according to claim 4 is viewed from the viewpoint of the growth rate, for example, at 0.02 nm / min or more, 2
a reaction with a growth rate of less than 2 nm / min
A reaction having a growth rate of min or more occurs stepwise.
Alternatively, it has a characteristic that a reaction having a growth rate of 0.02 nm / min or more and less than 2 nm / min is 15 minutes or less.

Hereinafter, the growth mechanism of the Ru film for showing the effectiveness of the present invention will be described. When the growth of the Ru film was examined in detail, it was found that the growth of Ru occurred after a certain time (introduction time) had elapsed. When the film was formed at 230 ° C,
It was found that there was an introduction time of 20 minutes or more. W and Ti
When a metal film used for an LSI such as N is formed by a CVD method, such an introduction time on the order of several tens of minutes is not seen, and it is understood that Ru CVD is very peculiar. Further, as a result of further detailed investigation of the Ru film thickness with respect to the introduction time and the growth time, as shown in FIG. 13, Ru grew at a very low growth rate during the introduction time, and a certain thickness or grain size (0 (About 1.5-1.5 nm), it was found that the growth rate sharply increased.

The reaction process during the introduction time was examined using a quadrupole mass spectrometer (Q-Mass).
₂ is decomposed into RuCp and Cp, RuCp becomes Ru
When RuCp is decomposed into a reaction decomposed into Cp and
Cp is decomposed into two carbon groups and three carbon groups,
It has been found that there is a reaction in which these groups are combined with Ru to form ruthenium methylacetylide (RuC≡CCH ₃ ) (see FIG. 11).

Further, when the reaction was examined in more detail,
During the introduction time, the raw material Ru is consumed in the reaction for generating ruthenium methyl acetylide, the amount of Ru used in the reaction in which RuCp is decomposed into Ru and Cp is small, and ruthenium methyl acetylide volatilizes to form Ru on the wafer. Therefore, it was found that the Ru film formation rate was extremely slow and the density was low. FIG. 20 shows a cross-sectional SEM image of the Ru film formed by such a reaction. It can be seen that the surface morphology is very poor due to the low initial nuclear density.

Therefore, several layers of Ru are formed densely as a catalyst before the CVD of Ru, and then Ru is formed by a CVD method.
It was found that a Ru film having a very smooth surface was obtained. In this case, no introduction time was observed, and it was found that the Ru film was growing immediately. This is because Ru functions as a catalyst and the Cp ring is decomposed into one carbon group and four carbon groups (or one carbon group and two two carbon groups) when the source gas is supplied. This is for accelerating the reaction. In addition, it has been found that a simple substance or a compound containing at least one group 8 or 1B element other than Ru as the catalyst is also effective.

When the underlayer was treated so that the initial nuclei were formed as densely as possible during the introduction time, the introduction time and the growth time were observed as in the case where the underlayer was not treated. It is shorter than when the substrate is not processed,
It was also found that the formed Ru film had a very good surface morphology. This is because by performing the base treatment, a negative charge is provided to the Ru (Cp) group and the like, and the reaction of generating a ruthenium acetylide derivative is suppressed.

From the above, as the capacitor electrode, R
When forming a film of u or RuO ₂ by the CVD method, a catalyst for accelerating the CVD reaction is densely formed on the base surface, so that the growth reaction of Ru or RuO ₂ occurs quickly, and the formed film is formed. Can have a smooth surface morphology (claim 1-3).

Further, by performing a base treatment for suppressing the formation of the ruthenium methylacetylide derivative generated during the introduction time, it is possible to increase the initial nucleation rate and increase the initial nucleus density. Surface morphology can be smoothed (claim 4-6).

[0025]

Embodiments of the present invention will be described below with reference to the drawings. (1) First Embodiment First, a manufacturing process of a capacitor according to a first embodiment of the present invention will be described with reference to FIGS. 1 (a) to 3 (g).

First, after an element isolation region 2 having an STI structure is formed on a p-type Si substrate 1, a gate insulating film 3a,
A MOS transistor including a gate electrode 3b (to be a word line) and a source / drain diffusion layer (n ⁺ diffusion layer) 4 is formed. After that, the interlayer insulating film 5a is deposited and flattened, and then the bit line 6 is formed. Thereafter, an interlayer insulating film 5b is further deposited and planarized, and then a contact hole is opened (FIG. 1A).

Next, after the W film 7 is deposited on the entire surface, the W film 7 on the interlayer insulating film 5b is removed by an etch-back method or a CMP method and buried only in the contact hole (FIG. 1B). Subsequently, after the interlayer insulating film 5c is deposited and planarized, a contact hole is opened (FIG. 1C).

Next, the substrate is immersed in an ethylene glycol solution of RuCl ₃ or a plating solution of Ru.
Ru8 of 5 nm or more is formed on the entire surface (FIG. 2D).
Thereafter, a substrate temperature of 180-400 ° C. and a pressure of 0.01-1.
Ru (Cp) with Ar gas as carrier at 0 Torr
₂ and O ₂ (O ₂ concentration of 40% or less in the atmosphere) are introduced into the chamber, and a Ru film 8 is deposited on the entire surface (FIG. 2E).
Next, after applying an SOG film (not shown) on the entire surface, the CM
The SOG film and the Ru film on the interlayer insulating film 5c are removed by the P method, and the SOG film remaining in the contact hole is removed by HF vapor to form a lower electrode made of the Ru film 8 (FIG. 2).
(F)).

Next, the (Ba, Sr) TiO ₃ film 10 is
It is deposited on the entire surface by the VD method. Thereafter, a substrate temperature of 100-2
The substrate was exposed to a mixed gas of Ru (Cp) ₂ and O ₂ using Ar gas as a carrier at 00 ° C. and a pressure of 1-100 Torr to form an initial nucleus.
Ru (Cp) ₂ and O ₂ (Ar atmosphere O ₂ concentration 40) using Ar gas as a carrier at a temperature of 0.01 ° C. and a pressure of 0.01-10 Torr.
% Or less) is introduced into the chamber, and a Ru film 11 is deposited on the entire surface and processed as an upper electrode (FIG. 3G).

As described above, immediately before performing Ru CVD, R
immersion in a solution containing u
The above-mentioned Ru nuclei can be densely provided. The reaction process of the Ru film in this case was examined in detail using a quadrupole mass spectrometer, and as a result, RuCp was found to have one carbon group and four carbon groups (or one carbon group and two carbon atoms). To the group of
It was found that the growth of Ru occurred in the reaction for producing u (see FIG. 12). Further, the Ru nucleus of 0.5 nm or more functions as a catalyst, and immediately after supplying the raw material gas,
A reaction in which the p-ring is decomposed into one carbon group and four carbon groups (or one carbon group and two two carbon groups) can be promoted, and a Ru film having a smooth surface can be obtained. Can be.

In the above example, the immersion treatment was performed in a solution containing Ru, but instead of Ru, Pt, Au, Ir, R
h, etc., when immersed in a solution containing an element of Group 8 or 1B, and a simple substance or a compound containing these elements is used as a nucleus,
A similar effect can be obtained by a similar catalytic action.

(2) Second Embodiment Next, a manufacturing process of a capacitor according to a second embodiment of the present invention will be described with reference to FIGS. 4 (a) to 6 (h).

First, after an element isolation region 2 having an STI structure is formed on a p-type Si substrate 1, a gate insulating film 3a,
A MOS transistor including the gate electrode 3b and the source / drain diffusion layer (n ⁺ diffusion layer) 4 is formed. After that, the interlayer insulating film 5a is deposited and flattened, and then the bit line 6 is formed. Thereafter, an interlayer insulating film 5b is further deposited and planarized, and then a silicon nitride film 5d is deposited, and a contact hole is opened (FIG. 4A).

Next, after a W film 7 is deposited on the entire surface, the W film 7 on the silicon nitride film 5d is etched back by an etch-back method or a CMP method.
It is removed by a method and buried only inside the contact hole (FIG. 4B). Subsequently, after an interlayer insulating film 5c is deposited and planarized, a contact hole is opened (FIG. 4).
(C)).

Next, a thin Ru film 8 is formed by sputtering to a thickness of 0.5 nm or more.
(D)). Then, Ru (EtCp) ₂ (Et represents an ethyl group) and O _{2 using} Ar gas as a carrier at a substrate temperature of 180 to 400 ° C. and a pressure of 0.01 to 10 Torr.
(O ₂ concentration of 40% or less in the atmosphere) is introduced into the chamber, and a Ru film 8 is deposited on the entire surface (FIG. 5E). afterwards,
The Ru film 8 on the interlayer insulating film 5c is removed by the CMP method to bury the Ru film 8 in the contact hole (FIG. 5).
(F)). Further, the interlayer insulating film 5c is formed by wet etching or reactive ion etching with a dilute HF aqueous solution.
To form a lower electrode made of the Ru film 8 (FIG. 6).
(G)).

Next, the (Ba, Sr) TiO ₃ film 10 is
It is deposited on the entire surface by the VD method. Thereafter, a Ru film 11 is deposited on the entire surface in the same manner as in the case of the lower Ru electrode, and is processed as an upper electrode (FIG. 6 (h)).

As described above, by forming an ultra-thin Ru film of 0.5 nm or more immediately before performing Ru CVD,
Ru nuclei can be densely attached to the underlayer surface, and R
A catalytic action that promotes the reaction of immediately decomposing the Cp ring serving as the skeleton of EtCp into one carbon group and four carbon groups (or one carbon group and two two carbon groups) during u-CVD. As a result, as shown in the SEM image of FIG. 17, a Ru film having a smooth surface can be obtained.

In the above example, Ru is used by sputtering.
, But instead of Ru, Pt, Au, Ir,
Even when a nucleus is a simple substance or a compound containing a Group 8 or 1B element such as Rh, a catalytic action is similarly produced and the same effect can be obtained.

(3) Third Embodiment Next, a manufacturing process of a capacitor according to a third embodiment of the present invention will be described with reference to FIGS. 7 (d) to 7 (f). Since the steps up to the middle are the same as the steps shown in the first embodiment (the steps of FIGS. 1A to 1C), the first embodiment is referred to for these steps. The subsequent steps will be described.

After the step shown in FIG. 1C, the substrate is exposed to O ₂ plasma or Ar plasma.
At 00-450 ° C. under a pressure of 0.01-10 Torr, Ar
Ru (EtCp) ₂ and O ₂ (O ₂ concentration of 40% or less in the atmosphere) with a gas as a carrier are introduced into the chamber, and Ru is introduced.
The film 8 is deposited on the entire surface (FIG. 7D). Then, SOG
After a film (not shown) is applied on the entire surface, the SOG film and the Ru film 8 on the interlayer insulating film 5c are removed by a CMP method, and the SOG film remaining in the contact hole is removed by HF vapor to remove Ru.
A lower electrode made of the film 8 is formed (FIG. 7E).

Next, the (Ba, Sr) TiO ₃ film 10 is
It is deposited on the entire surface by the VD method. After that, as in the case of the lower Ru electrode 8, the substrate is exposed to O ₂ plasma or Ar plasma, and then a Ru film 11 is deposited by a CVD method and processed as an upper electrode (FIG. 7F).

As described above, by subjecting the substrate to plasma treatment before forming the lower and upper Ru electrodes, the source gas is easily adsorbed due to micro damage, and the nucleus density is increased. In addition, when a dangling bond is generated, electrons are donated to the Ru (EtCp) group, the acetylidation reaction of Ru is suppressed, and the reaction of generating metal Ru is promoted. For this reason, initial nuclei are easily formed, island growth and surface morphology deterioration can be prevented, and a capacitor having excellent characteristics can be realized.

Incidentally, although in the above example were treated with O ₂ plasma or an Ar plasma before the formation of Ru, N ₂
In plasma, Ne plasma, HCl, BCl ₃ ,
Cl _2, be treated in a plasma containing a halogen F ₂ or the like can increase the initial nucleus density, it is possible to form a good capacitor.

As a plasma generation method, a parallel plate type, a helicon type, an ECR type, an inductive coupling type, or the like can be used. Further, when the plasma treatment and the film formation of Ru are continuously performed without breaking vacuum using, for example, a cluster type CVD apparatus, a smoother Ru film can be obtained.

(4) Fourth Embodiment Next, a manufacturing process of a capacitor according to a fourth embodiment of the present invention will be described with reference to FIGS. 8 (d) to 9 (g). Note that the steps up to the middle are the same as the steps shown in the second embodiment (the steps of FIGS. 4A to 4C), and therefore these steps are referred to the second embodiment. The subsequent steps will be described.

After the step of FIG. 4C, an aqueous NH ₄ F solution
HCl aqueous solution or tetramethylammonium hydroxide ((CH ₃ ) ₄ NOH) aqueous solution, and then a substrate temperature of 180-400 ° C. and a pressure of 0.0
Ru at 1-10 Torr using Ar gas as a carrier
(Cp) ₂ and O ₂ (O ₂ concentration of 40% or less in the atmosphere) are introduced into the chamber, and a Ru film 8 is deposited on the entire surface (FIG. 8).
(D)). Then, Ru on the interlayer insulating film 5c is formed by the CMP method.
The film 8 is removed and the Ru film 8 is buried inside the contact hole (FIG. 8E). Further, the interlayer insulating film 5c is removed by wet etching using a dilute HF aqueous solution or reactive ion etching to form a lower electrode made of the Ru film 8 (FIG. 9F).

Further, a (Ba, Sr) TiO ₃ film 10 is deposited on the entire surface by the CVD method. Thereafter, a Ru film 11 is deposited on the entire surface as in the case of the lower Ru electrode, and processed as an upper electrode (FIG. 9G).

In this way, by performing the treatment in a solution containing a halogen ion or in an alkaline solution before forming the Ru electrode, electrons are supplied to the Ru (Cp) group from the anions adsorbed on the base surface, The acetylidation reaction of Ru is suppressed, and the reaction for generating metal Ru is promoted.
For this reason, initial nuclei are easily formed, island growth and surface morphology deterioration can be prevented, and a capacitor having excellent characteristics can be realized.

As described above, when the underlayer was processed so that the initial nuclei were formed as densely as possible during the introduction time, the introduction time and the growth time were observed as in the case where the underlayer was not processed. The time is shorter than when the base is not processed (in the case of the substrate temperature of 230 ° C., the time was 23 minutes without the processing, but now becomes 14 minutes by performing the processing).
Further, as shown in the SEM image of FIG. 18, it was found that the formed Ru film had a very good surface morphology. As described above, if the acetylidation reaction of Ru is suppressed so that the introduction time until the initial nucleus becomes large enough to cause the catalytic action is reduced, the R formed on the base surface can be reduced.
The amount of u increases, and the initial nuclear density acting as a catalyst can be improved. After a detailed investigation, by processing the groundwork so that the introduction time is within 15 minutes,
It has been found that a smooth Ru film can be obtained.

(5) Fifth Embodiment Next, a manufacturing process of a capacitor according to a fifth embodiment of the present invention will be described with reference to FIGS. 10 (d) to 10 (f). Since the steps up to the middle are the same as the steps shown in the first embodiment (the steps of FIGS. 1A to 1C), the first embodiment is referred to for these steps. The subsequent steps will be described.

After the step of FIG. 1C, the substrate temperature is set to 200 ° C.
The substrate is exposed to Cl ₂ gas or F ₂ gas diluted to 5% with a substrate temperature of 200 to 450 ° C. and a pressure of 0.01.
Ru (M) using Ar gas as a carrier at −10 Torr
eCp) ₂ (Me represents a methyl group) and O ₂ (O ₂ concentration of 40% or more in the atmosphere) were introduced into the chamber, and RuO was introduced.
_Two films 12 are deposited on the entire surface (FIG. 10D). afterwards,
After applying an SOG film (not shown) on the entire surface, the SOG film and the RuO ₂ film 12 on the interlayer insulating film 5c are removed by the CMP method, and the SOG film remaining in the contact hole is removed by HF vapor. A lower electrode made of the RuO ₂ film 12 is formed (FIG. 10E).

Next, the (Ba, Sr) TiO ₃ film 10 is
It is deposited on the entire surface by the VD method. Then, after treating with a halogen gas as in the case of forming the lower RuO ₂ electrode, RuO ₂
A film 13 is deposited on the entire surface and processed as an upper electrode (FIG. 1).
0 (f)).

As described above, by performing the treatment in an atmosphere containing halogen before forming the RuO ₂ electrode, the electrons adsorbed from the halogen adsorbed on the surface of the underlayer become Ru (MeCp).
It is provided to the group, suppresses the acetylidation reaction of Ru, promotes the production reaction of metal Ru, and promotes the reaction in which Ru and oxygen are combined to form RuO ₂ . For this reason, initial nuclei are easily formed, island growth and surface morphology deterioration can be prevented, and a capacitor having excellent characteristics can be realized.

Although the embodiments of the present invention have been described above, a Ru film having good surface morphology can be obtained by using the present invention. FIG. 19 shows Ru at 20 nm.
5 shows an SEM image when the film is made thinner. Despite the thin film thickness of 20 nm, no island-shaped growth was observed, and it was found that Ru with a very smooth surface was conformally formed.

The present invention is not limited to the above embodiments, but can be implemented with various modifications. In the above embodiment, the O ₂ gas is introduced into the chamber when Ru or RuO _{2 is} formed, but O ₃ or O radicals may be used instead of O ₂ . For example, when O radicals are used, O radicals generated by microwave discharge may be introduced into the chamber.

In the above embodiment, (Ba, Sr) TiO ₃ was used for the capacitor insulating film.
T, STO, Ta ₂ O ₅ , BTO, SBT or the like may be used. Further, a Ti film, a TiN film, or a laminated film of these may be deposited as an adhesion layer under the W film.

Further, Ru (Cp) ₂ , Ru (MeCp)
_The present invention can be applied to the case where the skeleton is a ligand of a Cp ring other than Ru (EtCp) ₂ . A similar effect can be obtained with metallocene derivatives of metals other than Ru.

In the description of the reaction mechanism, the case where Ru (Cp) ₂ is used as a raw material has been described in order to explain the reaction in an easy-to-understand manner, but one or more hydrogen atoms of the Cp group are replaced with a methyl group, an ethyl group or a propyl group. Even when a raw material substituted with an organic functional group such as a group is used, the Cp ring serving as the skeleton is decomposed as described above. In this case, for example, when the Cp ring of a methylcyclopentadienyl group (CH ₃ Cp group) is decomposed into one carbon and four carbon groups, the one carbon group has a methyl group, If reacted, acetaldehyde (CH ₃ CHO) or acetic acid (CH
₃ COOH) will produce a and formic acid (HCOOH) occurs (Formaldehyde (HCHO in the case of similar reactions Cp group only)). In addition, the present invention can be variously modified and implemented without departing from the spirit thereof.

[0059]

According to the present invention, by forming ruthenium or ruthenium oxide under predetermined conditions, island-like growth of ruthenium or ruthenium oxide is suppressed, and a smooth surface morphology can be obtained. Therefore, a highly reliable capacitor having excellent characteristics can be realized.

[Brief description of the drawings]

FIG. 1 is a process cross-sectional view showing a part of a manufacturing process according to a first embodiment of the present invention.

FIG. 2 is a process cross-sectional view showing a part of the manufacturing process according to the first embodiment of the present invention.

FIG. 3 is a process cross-sectional view showing a part of the manufacturing process according to the first embodiment of the present invention.

FIG. 4 is a process cross-sectional view showing a part of a manufacturing process according to a second embodiment of the present invention.

FIG. 5 is a process cross-sectional view showing a part of the manufacturing process according to the second embodiment of the present invention.

FIG. 6 is a process cross-sectional view showing a part of the manufacturing process according to the second embodiment of the present invention.

FIG. 7 is a process cross-sectional view showing a part of a manufacturing process according to a third embodiment of the present invention.

FIG. 8 is a process sectional view showing a part of a manufacturing process according to a fourth embodiment of the present invention.

FIG. 9 is a process cross-sectional view showing a part of a manufacturing process according to a fourth embodiment of the present invention.

FIG. 10 is a process sectional view showing a part of a manufacturing process according to a fifth embodiment of the present invention.

FIG. 11 is a diagram showing a difference spectrum between a mass spectrum at an introduction time at a substrate temperature of 230 ° C. and a mass spectrum at a room temperature.

FIG. 12 is a diagram showing a difference spectrum between a mass spectrum during Ru growth at a substrate temperature of 230 ° C. and a mass spectrum at room temperature.

FIG. 13 is a diagram schematically showing a relationship between a Ru film thickness and a gas supply time.

FIG. 14 is a process cross-sectional view showing a part of a manufacturing process according to a conventional technique.

FIG. 15 is a process cross-sectional view showing a part of a manufacturing process according to a conventional technique.

FIG. 16 is a diagram showing an example of a problem of the related art.

FIG. 17 is a micrograph showing an SEM image when Ru is formed into a film after forming a catalyst.

FIG. 18 illustrates a case where Ru is deposited after performing a base treatment.
A micrograph showing an EM image.

FIG. 19 is a micrograph showing an SEM image when Ru is thinned by the method of the present invention.

FIG. 20 is a micrograph showing an SEM image of a Ru film when the initial nuclear density is low.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Si substrate 2 ... Element isolation region 3a ... Gate insulating film 3b ... Gate electrode 4 ... S / D diffusion layer 5a, 5b, 5c ... Interlayer insulating film 5d ... Silicon nitride film 6 ... Bit line 7 ... W film 8,11 ... Ru film 9 ... SOG film 10 ... (Ba, Sr) TiO 3 film 12, 13 ... RuO ₂ film

Claims (6)

[Claims] In a method of manufacturing a semiconductor device having a capacitor using a metal oxide as a dielectric film and using a ruthenium film or a ruthenium oxide film as an electrode sandwiching the dielectric film, at least one of the electrodes is formed of ruthenocene or cyclo-oxide. The step of forming by a CVD method using an organic group ruthenocene in which at least one hydrogen of a pentadienyl ring is substituted by an organic functional group as a source gas is performed by using a cyclopentadienyl group as a ligand of the source gas or an organic group. Reaction of decomposing a cyclopentadienyl ring forming a skeleton of a cyclopentadienyl group having a functional group into one carbon group and four carbon groups, or one carbon group and two carbon two groups A method for manufacturing a semiconductor device, characterized in that the method is performed under conditions that promote a reaction for decomposing into a semiconductor device. 2. A process for accelerating the reaction for decomposing into one carbon group and four carbon groups or the reaction for decomposing into one carbon group and two two carbon groups, 2. The method for manufacturing a semiconductor device according to claim 1, wherein a treatment for forming a catalyst is performed on a surface of the formed base. 3. The method for manufacturing a semiconductor device according to claim 2, wherein the catalyst formed on the base surface is a substance containing at least an element of Group 8 or Group 1B. 4. A method for manufacturing a semiconductor device having a capacitor using a metal oxide as a dielectric film and a ruthenium film or a ruthenium oxide film as an electrode sandwiching the dielectric film, wherein at least one of the electrodes is made of ruthenocene or cycloalkyl. The step of forming by a CVD method using an organic group ruthenocene in which at least one hydrogen of a pentadienyl ring is substituted by an organic functional group as a source gas is performed by using a cyclopentadienyl group as a ligand of the source gas or an organic group. A method for manufacturing a semiconductor device, characterized in that the method is carried out under conditions that suppress a reaction in which a cyclopentadienyl ring forming a skeleton of a cyclopentadienyl group having a functional group is decomposed to generate a ruthenium acetylide derivative. 5. The semiconductor device according to claim 4, wherein a surface treatment is performed on a base on which the electrode is formed as a treatment for suppressing a reaction for producing the ruthenium acetylide derivative. Method. 6. The method of manufacturing a semiconductor device according to claim 5, wherein the surface treatment for the base is a treatment for causing a reaction for giving a negative charge to the constituents of the source gas.