JP2926050B2 - Semiconductor device and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device, and more particularly to a semiconductor device provided with a capacitor having a capacitor insulating film made of an insulating metal oxide film such as a ferroelectric film or a high dielectric film, and a method of manufacturing the same. .

[0002]

2. Description of the Related Art In recent years, with the progress of high speed and low power consumption of microcomputers and the like, consumer electronic devices have been further advanced, and the miniaturization of semiconductor devices used for these devices has been rapidly progressing. ing.

With the miniaturization of semiconductor devices, unnecessary radiation, which is electromagnetic noise emitted from electronic equipment, has become a serious problem. One of the means for reducing this unnecessary radiation is to use a ferroelectric film or a high dielectric film. Attention has been paid to a technology for incorporating a large-capacity capacitive element using a dielectric film as a capacitive insulating film in a semiconductor integrated circuit.

[0004] With the high integration of the dynamic RAM, a technique of using a high dielectric film instead of a conventional silicon oxide film or silicon nitride film as a capacitor insulating film has been widely studied.

Further, research and development on ferroelectric films having spontaneous polarization characteristics have been actively pursued with the aim of putting a non-volatile RAM capable of high-speed writing and reading at a low operating voltage to practical use. Note that in a ferroelectric memory using a ferroelectric film as a capacitor insulating film, the amount of charge flowing into and out of a data line of the ferroelectric memory differs depending on whether the spontaneous polarization state of the ferroelectric film is inverted. Utilize the phenomenon.

An important issue for realizing the above-described semiconductor device is to develop a technology capable of realizing high integration of a capacitor without deteriorating the characteristics of the capacitor.

Hereinafter, a conventional semiconductor device will be described with reference to FIG.

FIG. 13 shows a cross-sectional structure of a conventional semiconductor device. As shown in FIG. 13, a lower electrode 2 made of a first platinum film is formed on a semiconductor substrate 1 made of silicon.
A capacitor insulating film 3 made of a ferroelectric film and an upper electrode 4 made of a second platinum film are formed.
A capacitive element is constituted by the capacitive insulating film 3 and the upper electrode 4. An interlayer insulating film 5 made of a silicon oxide film, a silicon nitride film, or the like is deposited over the entire surface of the semiconductor substrate 1 including the capacitive element, and the interlayer insulating film 5 has a lower electrode contact hole 6 and an upper electrode. An electrode contact hole 7 is formed. A titanium film 8a, a first titanium nitride film 8b, an aluminum film 8c, and a second titanium nitride film 8d are formed on the interlayer insulating film 5 including the insides of the lower electrode contact hole 6 and the upper electrode contact hole 7.
Is formed.

A conventional method for manufacturing a semiconductor device will be described below with reference to FIGS.

First, as shown in FIG. 14A, a first platinum film 2A, a ferroelectric film 3A, and a second platinum film 4A are sequentially deposited over the entire surface of a semiconductor substrate 1, and then, FIG.
As shown in (b), the upper electrode 4 is formed by selectively etching the second platinum film 4A. Thereafter, in order to recover and stabilize the crystal structure of the ferroelectric film 3A, heat treatment is performed on the ferroelectric film 3A in an oxygen atmosphere.

Next, as shown in FIG. 14C, the ferroelectric film 3A and the first platinum film 2A are selectively etched to form the capacitor insulating film 3 made of the ferroelectric film 3A and the first platinum film 2A. The lower electrode 2 made of the platinum film 2A is formed. Thereafter, in order to recover and stabilize the crystal structure of the ferroelectric film constituting the capacitor insulating film 3, the capacitor insulating film 3 is subjected to a heat treatment in an oxygen atmosphere.

Next, as shown in FIG. 14D, after an interlayer insulating film 5 made of a silicon oxide film or a silicon nitride film is deposited over the entire surface of the semiconductor substrate 1, the lower portion of the interlayer insulating film 5 is formed. An electrode contact hole 6 and an upper electrode contact hole 7 are formed. Thereafter, in order to recover and stabilize the crystal structure of the ferroelectric film constituting the capacitor insulating film 3, the capacitor insulating film 3 is subjected to a heat treatment in an oxygen atmosphere.

In the above-described heat treatment step for recovering the crystal structure of the ferroelectric film, the lower electrode 2 or the upper electrode 4 reacts with the capacitive insulating film 3 to oxidize the lower electrode 2 or the upper electrode 4. In order to prevent such a situation, a platinum film, which does not easily react with the ferroelectric film 3A constituting the capacitive insulating film 3 during heat treatment and has oxidation resistance even at a high temperature, is used as the lower electrode 2 or the upper electrode 4. I have.

Next, as shown in FIG. 14E, the titanium film 8a and the first film 8a are formed over the entire surface of the semiconductor substrate 1 including the insides of the lower electrode contact hole 6 and the upper electrode contact hole 7. After sequentially depositing a titanium nitride film 8b, an aluminum film 8c, and a second titanium nitride film 8d, the wiring is patterned by photolithography to form the titanium film 8a, the first titanium nitride film 8b, the aluminum film 8c, A metal wiring 8 made of the second titanium nitride film 8d is formed. The titanium film 8a serves as an adhesion layer for improving the adhesion between the aluminum film 8c and the platinum film constituting the upper electrode 4, and the first titanium nitride film 8b allows aluminum of the aluminum film 8c to diffuse into the upper electrode 4. The second titanium nitride film 8 serves as a barrier layer for preventing
d serves as an antireflection film when patterning the wiring by photolithography.

Next, a titanium film 8a constituting the metal wiring 8 is formed.
In order to further improve the adhesion between the metal wiring 8 and the interlayer insulating film 5, a heat treatment is performed on the metal wiring 8.

[0016]

However, in a heat treatment step performed to stabilize the crystal structure of the ferroelectric film, the platinum film forming the upper electrode has a columnar crystal structure, so that the metal wiring and the interlayer insulating film have to be formed. In the heat treatment step performed to improve the adhesion of the metal, the titanium atoms of the titanium film forming the metal wiring diffuse into the capacitor insulating film through the crystal grain boundaries of the columnar crystals of the platinum film forming the upper electrode. .
For this reason, the composition of the ferroelectric film forming the capacitive insulating film changes, and thus there is a problem that the electrical characteristics of the capacitive element deteriorate.

The upper electrode is not limited to the case where the upper electrode is formed of a platinum film, but also has a columnar crystal structure when the upper electrode is an iridium film, a ruthenium film, a rhodium film, a palladium film or the like. There is a problem that titanium atoms of the titanium film forming the wiring diffuse into the capacitor insulating film through the grain boundaries of the columnar crystals forming the upper electrode.

In view of the above, according to the present invention, in a heat treatment step for a metal wiring having a titanium film provided on a capacitor, titanium atoms of the titanium film are formed by crystal grains of a metal crystal constituting an upper electrode of the capacitor. It is an object of the present invention to prevent a situation of diffusion into a capacitor insulating film through a field.

[0019]

In order to achieve the above object, a semiconductor device according to the present invention comprises a substrate, a capacitor lower electrode provided on the substrate, a capacitor insulating film comprising an insulating metal oxide film, and A capacitor element including a capacitor upper electrode; an interlayer insulating film provided on the capacitor element and having an opening reaching the capacitor upper electrode; and a capacitor upper electrode connected to the capacitor upper electrode through the opening on the interlayer insulating film. Provided to be connected
A metal wiring having a titanium film and a conductive layer provided between the capacitor upper electrode and the metal wiring to prevent titanium atoms forming the titanium film of the metal wiring from passing through the capacitor upper electrode and diffusing into the capacitor insulating film. A diffusion preventing film having a property.

According to the semiconductor device of the present invention, between the capacitor upper electrode and the metal wiring, titanium atoms forming the titanium film of the metal wiring are prevented from passing through the capacitor upper electrode and diffusing into the capacitor insulating film. Because the diffusion prevention film is provided,
In the heat treatment step for the metal wiring, the titanium atoms of the titanium film do not diffuse into the capacitor insulating film through the crystal grain boundaries of the metal crystal forming the capacitor upper electrode.

In the semiconductor device of the present invention, the diffusion preventing film is preferably a conductive metal nitride film or metal oxide film.

In the semiconductor device according to the present invention, the capacitance insulating film is preferably a ferroelectric film or a high dielectric film.

In the semiconductor device of the present invention, the titanium film is an adhesion layer provided below the metal wiring to improve the adhesion between the metal wiring and the upper electrode, and the diffusion prevention film is preferably a titanium nitride film. .

In the semiconductor device of the present invention, it is preferable that the capacitor upper electrode has a crystal structure having a crystal grain boundary.

In the first method of manufacturing a semiconductor device according to the present invention, a capacitive element composed of a capacitive lower electrode, a capacitive insulating film made of an insulating metal oxide film, and a capacitive upper electrode is formed on a substrate. A step of forming an interlayer insulating film having a contact hole reaching the capacitor upper electrode on the capacitive element, and blocking the passage of titanium atoms over the entire surface of the interlayer insulating film including the contact hole. Forming a conductive film, and patterning the conductive film so that at least a portion of the conductive film located inside the contact hole remains to form a diffusion prevention film made of the conductive film. Process, and on the interlayer insulating film,
Forming a metal wiring having a titanium film so as to be electrically connected to the capacitor upper electrode via the diffusion prevention film.

According to a second method of manufacturing a semiconductor device according to the present invention, a first metal film, an insulating metal oxide film,
A step of sequentially depositing a second metal film and a conductive film for preventing passage of titanium atoms, and patterning the second metal film and the conductive film using the same etching mask to form a second metal film and a conductive film. Forming a diffusion prevention film comprising a capacitor upper electrode and a conductive film; patterning an insulating metal oxide film to form a capacitor insulating film; and patterning the first metal film to form a capacitor lower electrode. Forming an interlayer insulating film having a contact hole reaching the capacitor upper electrode on the capacitive element composed of the capacitor lower electrode, the capacitor insulating film, and the capacitor upper electrode. Forming a metal wiring having a titanium film so as to be electrically connected to the capacitor upper electrode via the diffusion preventing film.

A third method of manufacturing a semiconductor device according to the present invention includes a step of forming a capacitor insulating film comprising a capacitor lower electrode and an insulating metal oxide film on a substrate; Depositing an interlayer insulating film having an opening in a region where the capacitor upper electrode is formed on the substrate, and passing a metal film and titanium atoms over the entire surface of the interlayer insulating film including the opening. A step of sequentially forming a conductive film to be blocked, a step of forming a resist pattern at a portion corresponding to the opening on the conductive film, and a step of performing dry etching on the metal film and the conductive film using the resist pattern as a mask. Forming a capacitor upper electrode made of a metal film and a diffusion prevention film made of a conductive film by leaving a portion of the metal film and the conductive film located at the opening, and a resist pattern. After removal of, on the interlayer insulating film, so as to be connected capacitor upper electrode electrically via the diffusion preventing film, and a step of forming a metal wire having a titanium film.

In the first to third methods of manufacturing a semiconductor device, the conductive film is preferably a conductive metal nitride film or metal oxide film.

In the first to third methods of manufacturing a semiconductor device, the capacitance insulating film is preferably a ferroelectric film or a high dielectric film.

In the first to third methods of manufacturing a semiconductor device, the titanium film is provided below the metal wiring and is an adhesion layer for improving the adhesion between the metal wiring and the capacitor upper electrode.
The diffusion prevention film is preferably a titanium nitride film.

In the first to third methods of manufacturing a semiconductor device, the capacitor upper electrode preferably has a crystal structure having a crystal grain boundary.

[0032]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) Hereinafter, a semiconductor device according to a first embodiment of the present invention will be described with reference to FIG.

FIG. 1 shows a sectional structure of a semiconductor device according to the first embodiment. As shown in FIG. 1, a lower electrode made of a first platinum film is formed on a semiconductor substrate 10 made of silicon. 11, a capacitor insulating film 12 made of an insulating metal oxide film such as a ferroelectric film or a high dielectric film and an upper electrode 13 made of a second platinum film are sequentially formed. A capacitance element is constituted by 12 and the upper electrode 13. In this case, the lower electrode 11 is larger than the upper electrode 13 so that the metal wiring electrically connected to the lower electrode 11 passes through the side of the upper electrode 13 and is drawn upward.

An interlayer insulating film 1 made of, for example, a silicon oxide film is formed over the entire surface of the semiconductor substrate 10 including the capacitive element.
In the interlayer insulating film 14, a contact hole 15 for a lower electrode and a contact hole 16 for an upper electrode are formed.

A feature of the first embodiment is that a conductive metal nitride film such as a nitride is formed on the bottom and wall surfaces of the upper electrode contact hole 16 and on the periphery of the upper electrode contact hole 16 on the interlayer insulating film 14. A diffusion preventing conductive film 17 made of a titanium film is formed.

The interlayer insulating film 1 including the insides of the lower electrode contact hole 15 and the upper electrode contact hole 16
4, a titanium film 18a, a first titanium nitride film 18
b, aluminum film 18c and second titanium nitride film 18
A metal wiring 18 made of d is formed. in this case,
One metal wiring 18 is provided in the lower electrode contact hole 15.
Is electrically connected directly to the lower electrode 15 inside, and the other metal wiring 18 is electrically connected to the lower electrode 15 via the upper electrode 13 and the diffusion preventing conductive film 17 inside the upper electrode contact hole 16. It is connected.

The titanium film 18a serves as an adhesion layer for improving the adhesion between the interlayer insulating film 14 and the metal wiring 18 and also improving the adhesion between the aluminum film 18c and the lower electrode 11 or the upper electrode 13. Titanium nitride film 18b
The aluminum of the aluminum film 18c is the upper electrode 13
The second titanium nitride film 18d becomes an anti-reflection film when patterning the wiring by photolithography.

Hereinafter, a method for manufacturing a semiconductor device according to the first embodiment of the present invention will be described with reference to FIGS. 6 (a) to 6 (c) and 7 (a) to 7 (c).

First, as shown in FIG. 6A, a first platinum film 11A, a ferroelectric film 12A and a second platinum film 13A are sequentially deposited on the entire surface of the semiconductor substrate 10.

Next, as shown in FIG. 6B, after the upper electrode 13 is formed by selectively etching the second platinum film 13A, the ferroelectric film 12A and the first platinum film 11A are removed. By selectively etching, the capacitance insulating film 12 made of the ferroelectric film 12A and the lower electrode 11 made of the first platinum film 11A are formed. In this case, the ferroelectric film 12A and the first
It is preferable to etch the platinum film 11A using the same mask because mask displacement can be prevented, but the ferroelectric film 12A and the first platinum film 11A may be separately etched using different masks. . Thereafter, the capacitor insulating film 12 is selectively etched to form a region from which a metal wiring electrically connected to the lower electrode 11 is drawn upward, and then the ferroelectric material forming the capacitor insulating film 12 is formed. In order to recover and stabilize the crystal structure of the body film, heat treatment is performed on the capacitive insulating film 12 in an oxygen atmosphere.

Next, as shown in FIG. 6C, after an interlayer insulating film 14 made of a silicon oxide film is deposited over the entire surface of the semiconductor substrate 10, the interlayer insulating film 14 is selected. By etching, a contact hole 15 for the lower electrode and a contact hole 16 for the upper electrode are formed. Thereafter, in order to recover and stabilize the crystal structure of the ferroelectric film constituting the capacitor insulating film 12, the capacitor insulating film 1
2 is subjected to a heat treatment in an oxygen atmosphere.

Next, as shown in FIG. 7A, a titanium nitride film 17A is deposited over the entire surface of the semiconductor substrate 10 including the insides of the lower electrode contact hole 15 and the upper electrode contact hole 16. After that, the titanium nitride film 17
A resist pattern 19 is formed on A at a position corresponding to the upper electrode contact hole 16 and its peripheral portion.

Next, as shown in FIG. 7 (b), dry etching is performed on the titanium nitride film 17A using the resist pattern 19 as a mask to form the titanium nitride film 17A. Then, a diffusion preventing conductive film 17 is formed to cover the wall surface and the peripheral portion of the upper electrode contact hole 16 on the upper surface of the interlayer insulating film 14.

Next, as shown in FIG. 7C, a titanium film 18 is formed on the diffusion preventing conductive film 17 and the interlayer insulating film 14.
a, first titanium nitride film 18b, aluminum film 18c
After sequentially depositing the second titanium nitride film 18d and patterning the wiring by photolithography,
The metal wiring 18 is formed.

Next, the titanium film 1 forming the metal wiring 18
In order to further improve the adhesion between 8a and interlayer insulating film 14, heat treatment is performed on metal wiring 18.

According to the first embodiment, the bottom and wall surfaces of the upper electrode contact hole 16 and the interlayer insulating film 14 are formed.
The peripheral portion of the upper electrode contact hole 16 on the upper surface is covered with a diffusion preventing conductive film 17 made of a titanium nitride film 17A having no crystal grain boundaries and a dense crystal structure. Does not pass through the conductive film 17 for preventing diffusion. Therefore, in the heat treatment step for the metal wiring 18, it is possible to prevent the titanium atoms of the titanium film 18 a from diffusing into the capacitor insulating film 12 through the crystal grain boundaries of the metal crystal forming the upper electrode 13. Therefore, according to the first embodiment, a semiconductor device having a highly reliable capacitor can be realized.

According to the first embodiment, not only the inside of the contact hole 16 for the upper electrode but also the peripheral portion of the contact hole 16 for the upper electrode on the upper surface of the interlayer insulating film 14 is covered by the conductive film 17 for diffusion prevention. As a result, even if the mask for patterning the titanium nitride film 17A is slightly displaced, the bottom surface of the upper electrode contact hole 16 can be reliably covered with the diffusion preventing conductive film 17.

Hereinafter, evaluation of the semiconductor device according to the first embodiment will be described.

Table 1 shows a comparison result between the characteristics of the capacitor in the semiconductor device according to the first embodiment and the characteristics of the capacitor in the conventional semiconductor device.

[0050]

[Table 1]

As can be seen from Table 1, in the first embodiment, the insulation resistance of the capacitance element is 40 V, which is twice the insulation resistance of the conventional capacitance element. Also,
The data retention period is 10 years, which is about 10 times that of the conventional capacitor.

Second Embodiment Hereinafter, a semiconductor device according to a second embodiment of the present invention will be described with reference to FIG.

FIG. 2 shows a sectional structure of a semiconductor device according to the second embodiment. As shown in FIG. 2, a lower electrode made of a first platinum film is formed on a semiconductor substrate 20 made of silicon. 21, a capacitor insulating film 22 made of an insulating metal oxide film such as a ferroelectric film or a high dielectric film, and an upper electrode 23 made of a second platinum film are sequentially formed. A capacitor is formed by the film 22 and the upper electrode 23.

An interlayer insulating film 2 made of, for example, a silicon oxide film is formed over the entire surface of the semiconductor substrate 20 including the capacitive element.
4 are formed, and a contact hole 25 for a lower electrode and a contact hole 26 for an upper electrode are formed in the interlayer insulating film 24.

As a feature of the second embodiment, the inside of the upper electrode contact hole 26 is filled with a diffusion preventing conductive film 27 made of a titanium nitride film.

On the interlayer insulating film 24 including the inside of the lower electrode contact hole 25, a metal wiring 28 composed of a titanium film 28a, a first titanium nitride film 28b, an aluminum film 28c and a second titanium nitride film 28d. Are formed. In this case, one metal wiring 28 is directly electrically connected to the lower electrode 21 inside the lower electrode contact hole 25, and the other metal wiring 28
Above the upper electrode contact hole 26, the upper electrode 23 is electrically connected to the upper electrode 23 via a diffusion preventing conductive film 27. That is, since the other metal wiring 28 is electrically connected to the upper electrode 23 without bending in the vertical direction, the electrical connection between the other metal wiring 28 and the upper electrode 23 is ensured.

Hereinafter, a semiconductor device according to a modification of the second embodiment of the present invention will be described with reference to FIG.

FIG. 3 shows a cross-sectional structure of a semiconductor device according to a modification of the second embodiment.
Only the points different from the above embodiment will be described.

As a feature of the modification of the second embodiment, a diffusion preventing conductive film 27 made of, for example, a titanium nitride film is provided only in the lower portion inside the upper electrode contact hole 26.
Has been deposited. Therefore, the metal wiring 28 including the titanium film 28a, the first titanium nitride film 28b, the aluminum film 28c, and the second titanium nitride film 28d enters the inside of the upper electrode contact hole 26. Therefore, one metal wiring 28 is directly electrically connected to the lower electrode 21 inside the lower electrode contact hole 25, and the other metal wiring 28 is connected to the upper electrode inside the upper electrode contact hole 26. It is electrically connected to the electrode 23 via the diffusion preventing conductive film 27.

Hereinafter, a method for manufacturing a semiconductor device according to the second embodiment of the present invention will be described with reference to FIGS. 8 (a) to 8 (c) and 9 (a) to 9 (c).

First, as shown in FIG. 8A, a first platinum film 21A, a ferroelectric film 22A and a second platinum film 23A are sequentially deposited on the entire surface of a semiconductor substrate 20.

Next, as shown in FIG. 8B, after the second platinum film 23A is selectively etched to form the upper electrode 23, the ferroelectric film 22A and the first platinum film 21A are removed. By selectively etching, a capacitance insulating film 22 made of a ferroelectric film 22A and a lower electrode 21 made of a first platinum film 21A are formed. Thereafter, the capacitor insulating film 22 is selectively etched to form a region from which a metal wiring electrically connected to the lower electrode 21 is drawn upward, and then the ferroelectric material forming the capacitor insulating film 22 is formed. In order to recover and stabilize the crystal structure of the body film, heat treatment is performed on the capacitive insulating film 22 in an oxygen atmosphere.

Next, as shown in FIG. 8C, after an interlayer insulating film 24 made of a silicon oxide film is deposited over the entire surface of the semiconductor substrate 20, the interlayer insulating film 24 is selected. The lower electrode contact hole 25 and the upper electrode contact hole 26 are formed by etching. Thereafter, in order to recover and stabilize the crystal structure of the ferroelectric film constituting the capacitor insulating film 22, the capacitor insulating film 2
2 is subjected to a heat treatment in an oxygen atmosphere.

Next, as shown in FIG. 9A, after a titanium nitride film 27A is deposited over the entire surface of the semiconductor substrate 10, a contact hole 26 for the upper electrode is formed on the titanium nitride film 27A. A resist pattern 29 is formed at a corresponding portion.

Next, as shown in FIG. 9B, after the titanium nitride film 27A is dry-etched using the resist pattern 29 as a mask, the resist pattern 2
By removing 9, a diffusion preventing conductive film 27 made of a titanium nitride film 27 </ b> A is formed only inside the upper electrode contact hole 26.

Next, as shown in FIG. 9C, a titanium film 28 is formed on the diffusion preventing conductive film 27 and the interlayer insulating film 24.
a, first titanium nitride film 28b, aluminum film 28c
After the formation of the metal wiring 28 made of the second titanium nitride film 28d, a heat treatment is performed on the metal wiring 28 in order to further improve the adhesion between the titanium film 28a constituting the metal wiring 28 and the interlayer insulating film 24. Perform

According to the second embodiment or its modification,
A titanium nitride film 27A having no crystal grain boundaries and a dense crystal structure inside the upper electrode contact hole 26
Since the diffusion preventing conductive film 27 made of
The titanium atoms of the titanium film 28 a constituting the metal wiring 28 do not pass through the diffusion preventing conductive film 27. Therefore, in the heat treatment step for the metal wiring 28, the titanium film 28a
Can be prevented from being diffused into the capacitor insulating film 22 through the crystal grain boundaries of the metal crystals constituting the upper electrode 23. Therefore, according to the second embodiment or its modification, a semiconductor device having a highly reliable capacitor can be realized.

According to the second embodiment, the conductive film 27 for preventing diffusion is formed inside the contact hole 26 for the upper electrode.
Is filled, the metal wiring 28 is not bent at the portion of the upper electrode contact hole 26,
The contact between the metal wiring 28 and the upper electrode 23 is good.

Hereinafter, evaluation of the semiconductor device according to the second embodiment will be described.

Table 2 shows a comparison result between the characteristics of the capacitor in the semiconductor device according to the second embodiment and the characteristics of the capacitor in the conventional semiconductor device.

[0071]

[Table 2]

As can be seen from Table 2, in the second embodiment, the insulation resistance of the capacitor is 40 V, which is twice the insulation resistance of the conventional capacitor. Also,
The data retention period is 10 years, which is about 10 times that of the conventional capacitor.

Third Embodiment Hereinafter, a semiconductor device according to a third embodiment of the present invention will be described with reference to FIG.

FIG. 4 shows a sectional structure of a semiconductor device according to the third embodiment. As shown in FIG. 4, a lower electrode made of a first platinum film is formed on a semiconductor substrate 30 made of silicon. A capacitor insulating film 32 made of an insulating metal oxide film such as a ferroelectric film or a high dielectric film, and an upper electrode 33 made of a second platinum film are sequentially formed. A capacitive element is constituted by the film 32 and the upper electrode 33.

An interlayer insulating film 34 made of a silicon oxide film or a silicon nitride film is deposited over the entire surface of the semiconductor substrate 30 including the capacitor element.
Are formed with a contact hole 35 for a lower electrode and a contact hole 36 for an upper electrode.

The feature of the third embodiment is that the upper electrode 3
On 3, a diffusion preventing conductive film 37 having the same planar shape as the upper electrode 33 and made of a titanium nitride film is formed.

The interlayer insulating film 3 including the insides of the lower electrode contact hole 35 and the upper electrode contact hole 36
4, a titanium film 38a and a first titanium nitride film 38
b, aluminum film 38c and second titanium nitride film 38
A metal wiring 38 made of d is formed. in this case,
One metal wiring 38 is formed in the lower electrode contact hole 35.
Is electrically connected directly to the lower electrode 35 inside, and the other metal wiring 38 is electrically connected via the upper electrode 33 and the diffusion preventing conductive film 37 above the upper electrode contact hole 36. It is connected.

Hereinafter, a method for manufacturing a semiconductor device according to the third embodiment of the present invention will be described with reference to FIGS.

First, as shown in FIG. 10A, a first platinum film 31A, a ferroelectric film 32A, a second platinum film 33A and a titanium nitride film 3 are formed on the entire surface of a semiconductor substrate 30.
7A is sequentially deposited.

Next, as shown in FIG. 10B, the titanium nitride film 37A and the second platinum film 33A are patterned using the same etching mask to prevent the diffusion of the titanium nitride film 37A. Conductive film 37 and second
After the upper electrode 33 made of the platinum film 33A is formed, a heat treatment is performed on the ferroelectric film 32A in an oxygen atmosphere in order to recover and stabilize the crystal structure of the ferroelectric film 32A.

Next, as shown in FIG. 10C, the ferroelectric film 32A and the first platinum film 31A are patterned to form a capacitor insulating film 3 made of the ferroelectric film 32A.
After forming the lower electrode 31 composed of the second and first platinum films 31A, the lower electrode 31 is selectively formed on the capacitive insulating film 32 in order to form a region for drawing out a metal wiring electrically connected to the lower electrode 31 upward. Is etched. Thereafter, in order to recover and stabilize the crystal structure of the ferroelectric film constituting the capacitive insulating film 32, a heat treatment is performed on the capacitive insulating film 32 in an oxygen atmosphere.

Next, as shown in FIG. 10D, an interlayer insulating film 34 made of a silicon oxide film is deposited over the entire surface of the semiconductor substrate 30 and then selected for the interlayer insulating film 34. The lower electrode contact hole 35 and the upper electrode contact hole 36 are formed by etching. Thereafter, in order to recover and stabilize the crystal structure of the ferroelectric film forming the capacitance insulating film 32, the heat treatment is performed on the capacitance insulating film 12 in an oxygen atmosphere.

Next, as shown in FIG. 10E, a titanium film 3 is formed on the diffusion preventing conductive film 37 and the interlayer insulating film 34.
8a, first titanium nitride film 38b, aluminum film 38
metal wiring 38 composed of c and second titanium nitride film 38d
Is formed, and then a titanium film 38a constituting the metal wiring 38 is formed.
To further improve the adhesion between the substrate and the interlayer insulating film 34,
Heat treatment is performed on the metal wiring 38.

According to the third embodiment, a diffusion-preventing conductive film 37 made of a titanium nitride film 37A having no crystal grain boundaries and having a dense crystal structure is formed inside the upper electrode contact hole 36. Therefore, the titanium atoms of the titanium film 38 a constituting the metal wiring 38 do not pass through the diffusion preventing conductive film 37. For this reason, in the heat treatment step for the metal wiring 38, it is possible to prevent the titanium atoms of the titanium film 38 a from diffusing into the capacitor insulating film 32 through the crystal grain boundaries of the metal crystal forming the upper electrode 33. Therefore, according to the third embodiment, a semiconductor device having a highly reliable capacitive element can be realized.

Hereinafter, evaluation of the semiconductor device according to the third embodiment will be described.

Table 3 shows a comparison result between the characteristics of the capacitor in the semiconductor device according to the third embodiment and the characteristics of the capacitor in the conventional semiconductor device.

[0087]

[Table 3]

As can be seen from Table 3, in the third embodiment, the insulation resistance of the capacitor is 40 V, which is twice the insulation resistance of the conventional capacitor. Also,
The data retention period is 10 years, which is about 10 times that of the conventional capacitor.

(Fourth Embodiment) Hereinafter, a semiconductor device according to a fourth embodiment of the present invention will be described with reference to FIG.

FIG. 5 shows a sectional structure of a semiconductor device according to the fourth embodiment. As shown in FIG. 5, a lower electrode made of a first platinum film is formed on a semiconductor substrate 40 made of silicon. 41, a capacitor insulating film 42 made of an insulating metal oxide film such as a ferroelectric film or a high dielectric film, and an upper electrode 43 made of a second platinum film are sequentially formed. A capacitor is formed by the film 42 and the upper electrode 43.

An interlayer insulating film 44 made of a silicon oxide film or a silicon nitride film is deposited on the entire surface of the semiconductor substrate 40 including the capacitor element.
Are formed with a contact hole 45 for a lower electrode and a contact hole 46 for an upper electrode.

As a feature of the fourth embodiment, a diffusion preventing conductive film 47 made of, for example, a titanium nitride film is deposited only in the lower portion inside the lower electrode contact hole 45 and the upper electrode contact hole 46.

The interlayer insulating film 4 including the insides of the lower electrode contact hole 45 and the upper electrode contact hole 46
4, a titanium film 48a and a first titanium nitride film 48
b, aluminum film 48c and second titanium nitride film 48
A metal wiring 48 made of d is formed. in this case,
One metal wiring 48 is provided with a lower electrode contact hole 45.
Is electrically connected to the lower electrode 41 through the conductive film 47 for preventing diffusion,
Numeral 8 is electrically connected to the upper electrode 43 via a diffusion preventing conductive film 47 inside the upper electrode contact hole 46.

Hereinafter, a method of manufacturing a semiconductor device according to the fourth embodiment of the present invention will be described with reference to FIGS. 11 (a) to 11 (c) and FIGS. 12 (a) to 12 (c).

First, as shown in FIG. 11A, a first platinum film 41A and a ferroelectric film 42A are sequentially deposited on the entire surface of a semiconductor substrate 40.

Next, as shown in FIG. 11B, the ferroelectric film 42A and the first platinum film 41A are selectively etched to form a capacitor insulating film 42 made of the ferroelectric film 42A. And lower electrode 41 made of first platinum film 41A
Is formed, the lower electrode 41 is
Etching is selectively performed in order to form a region from which a metal wiring electrically connected to the semiconductor device is drawn upward. afterwards,
In order to recover and stabilize the crystal structure of the ferroelectric film constituting the capacitor insulating film 42, the capacitor insulating film 42 is subjected to a heat treatment in an oxygen atmosphere.

Next, as shown in FIG. 11C, after an interlayer insulating film 44 is deposited over the entire surface of the semiconductor substrate 40, a contact hole for a lower electrode is formed on the interlayer insulating film 44. A first resist pattern 49 having an opening in the region and the upper electrode contact hole forming region is formed. Thereafter, patterning is performed on the interlayer insulating film 44 using the first resist pattern 49 as an etching mask, and a contact hole 45 for a lower electrode and a contact hole 46 for an upper electrode are formed in the interlayer insulating film 44.

Next, as shown in FIG. 12A, after removing the first resist pattern 49, the first resist pattern 49 is removed over the entire surface including the insides of the lower electrode contact hole 45 and the upper electrode contact hole. A second platinum film 43A and a titanium nitride film 47A are sequentially deposited. Thereafter, a second resist pattern 50 is formed on the titanium nitride film 47A at a position corresponding to the upper electrode contact hole 46.

Next, as shown in FIG. 12B, dry etching is performed on the second platinum film 43A and the titanium nitride film 47A using the second resist pattern 50 as a mask. By removing the pattern 50, the upper electrode 43 made of the second platinum film 43A and the conductive film 47 for preventing diffusion made of the titanium nitride film 47A are formed inside the contact hole 46 for forming the upper electrode.

Next, as shown in FIG. 12C, a titanium film 4 is formed on the diffusion preventing conductive film 47 and the interlayer insulating film 44.
8a, first titanium nitride film 48b, aluminum film 48
metal wiring 48 composed of c and second titanium nitride film 48d
Is formed, a titanium film 48a forming the metal wiring 48 is formed.
To further improve the adhesion between the substrate and the interlayer insulating film 44,
Heat treatment is performed on the metal wiring 48.

According to the fourth embodiment, a diffusion-preventing conductive film 47 made of a titanium nitride film 47A having no crystal grain boundaries and having a dense crystal structure is formed inside the upper electrode contact hole 46. Therefore, the titanium atoms of the titanium film 48 a constituting the metal wiring 48 do not pass through the diffusion preventing conductive film 47. Therefore, in the heat treatment step for the metal wiring 48, it is possible to prevent the titanium atoms of the titanium film 48a from diffusing into the capacitor insulating film 42 through the crystal grain boundaries of the metal crystal forming the upper electrode 43. Therefore, according to the fourth embodiment, a semiconductor device having a highly reliable capacitive element can be realized.

Hereinafter, evaluation of the semiconductor device according to the fourth embodiment will be described.

Table 4 shows a comparison result between the characteristics of the capacitor in the semiconductor device according to the fourth embodiment and the characteristics of the capacitor in the conventional semiconductor device.

[0104]

[Table 4]

As can be seen from Table 4, in the fourth embodiment, the insulation resistance of the capacitor is 40 V, which is twice the insulation resistance of the conventional capacitor. Also,
The data retention period is 10 years, which is about 10 times that of the conventional capacitor.

In the first to fourth embodiments, the titanium nitride film is used as the diffusion preventing conductive films 17, 27, 37, and 47. Instead, tungsten, iridium, tantalum, and rhodium are used. A metal film made of at least one element selected from the group consisting of palladium, zirconium, niobium and vanadium, and at least one element selected from the group consisting of tungsten, tantalum, zirconium, niobium and vanadium. May be used, or a metal oxide film of at least one element selected from the group consisting of iridium, rhodium, palladium, osmium and ruthenium may be used. These metal films, metal nitride films, and metal oxide films have no crystal grain boundaries and have a dense crystal structure.
The passage of titanium atoms in the titanium films constituting 8, 48 is prevented.

The diffusion preventing conductive films 17, 27, 3
When the above-mentioned metal oxide film is used as 7 and 47, since the metal oxide film has conductivity in an oxide state, the crystal of the ferroelectric film forming the capacitance insulating films 12, 22, 32 and 42 is formed. Even if heat treatment is performed in an oxygen atmosphere to recover and stabilize the structure, the conductivity is not impaired.

Further, the diffusion preventing conductive films 17, 27, 3
As the layers 7 and 47, a laminate including at least two of the above-described metal films, metal nitride films and metal oxide films may be used.

In the first to fourth embodiments, the lower electrodes 11, 21, 31, 41 or the upper electrodes 13, 23, 3
As the layers 3 and 43, a multilayer film containing a platinum film and iridium oxide may be used instead of the platinum film.

In the third or fourth embodiment, the upper electrodes 33 and 43 having a small thickness and the conductive film 37 for preventing diffusion are provided.
47 may be alternately stacked by a plurality of layers. This makes it possible to obtain a stable upper electrode without deformation due to thermal expansion.

In the first to fourth embodiments, the ferroelectric films constituting the capacitance insulating films 12, 22, 32, and 42 are made of a perovskite ferroelectric material such as barium titanate or lead zirconate titanate. A film or a bismuth layered perovskite-type ferroelectric film such as SrBi ₂ Ta ₂ O ₉ may be used.

Further, the capacitance insulating films 12, 22, 32, 42
When an insulating metal oxide film other than a ferroelectric film, for example, a high dielectric film is used, the capacitive element can be applied to a dynamic RAM.

In the first to fourth embodiments, as the interlayer insulating films 14, 24, 34, and 44, a silicon nitride film or a silicon nitride oxide film may be used instead of the silicon oxide film. Further, the semiconductor substrates 10, 20, 30, 40
For example, an insulating substrate such as a glass substrate, a conductive substrate, or a semiconductor substrate on which a transistor or the like is formed may be used.

[0114]

According to the semiconductor device of the present invention, since the diffusion preventing film is provided between the capacitor upper electrode and the metal wiring, the titanium atom of the titanium film forming the metal wiring is formed in the heat treatment step for the metal wiring. Does not diffuse into the capacitor insulating film through the crystal grain boundary of the metal crystal constituting the capacitor upper electrode, and thus a semiconductor device having a highly reliable capacitor can be realized.

In the semiconductor device of the present invention, if the diffusion prevention film is a conductive metal nitride film or metal oxide film,
Since the conductive metal nitride film or metal oxide film has no crystal grain boundaries and has a dense crystal structure, the passage of titanium atoms can be reliably prevented. In particular, when the diffusion prevention film is a conductive metal oxide film, the metal oxide film has conductivity in an oxide state, so that the oxygen is recovered to restore the crystal structure of the ferroelectric film constituting the capacitive insulating film. Even if heat treatment is performed in an atmosphere, conductivity is not impaired.

In the semiconductor device according to the present invention, when the capacitance insulating film is a ferroelectric film, a highly reliable nonvolatile memory can be obtained. When the capacitance insulating film is a high dielectric film, A highly reliable dynamic memory can be obtained.

In the semiconductor device of the present invention, when the titanium film is an adhesion layer for improving the adhesion between the metal wiring and the upper electrode, the adhesion between the metal wiring and the upper electrode can be improved and the diffusion can be improved. If the anti-diffusion film is a titanium nitride film, by-products are not formed when the anti-diffusion film is deposited, and even if the titanium of the titanium film slightly diffuses into the anti-diffusion film, the properties of the anti-diffusion film do not change. Characteristics are stabilized.

In the semiconductor device of the present invention, if the capacitor upper electrode has a crystal structure having a crystal grain boundary, titanium atoms can easily pass through the capacitor upper electrode, but titanium atoms can be diffused by the diffusion preventing film. Since it is prevented from reaching the electrode, it does not diffuse into the capacitor insulating film.

According to the first method for manufacturing a semiconductor device, after a conductive film for preventing passage of titanium atoms is deposited on an interlayer insulating film having a contact hole formed on a capacitor, the conductive film is formed. Patterning the
A portion of the conductive film located inside the contact hole is left, and then a metal wiring having a titanium film is formed.
It is possible to reliably provide a diffusion prevention film for preventing titanium atoms from passing through the capacitor upper electrode and diffusing into the capacitor insulating film.

According to the second method for manufacturing a semiconductor device, the first metal film, the insulating metal oxide film, the second metal film, and the conductive film for preventing passage of titanium atoms are sequentially deposited. After patterning the second metal film and the conductive film to form a capacitor upper electrode and a diffusion prevention film, a metal wiring having a titanium film is formed via an interlayer insulating film having a contact hole. An anti-diffusion film for preventing titanium atoms from passing through the capacitor upper electrode and diffusing into the capacitor insulating film can be reliably provided between the upper electrode and the metal wiring.

According to the third method of manufacturing a semiconductor device, a metal film and titanium atoms are prevented from passing over an interlayer insulating film formed on a capacitor insulating film and having an opening in a region where a capacitor upper electrode is formed. After sequentially depositing a conductive film to be formed, dry etching is performed on the metal film and the conductive film using a resist pattern formed at a portion corresponding to the opening as a mask, thereby forming a capacitor upper electrode made of a metal film and a conductive film. Since a capacitor insulating film made of a film is formed, and then a metal wiring having a titanium film is formed, titanium atoms pass through the capacitor upper electrode between the upper electrode of the capacitor element and the metal wiring to form the capacitor insulating film. It is possible to reliably provide a diffusion prevention film for preventing diffusion.

Therefore, according to the first to third methods for manufacturing a semiconductor device, the semiconductor device according to the present invention can be reliably manufactured.

[Brief description of the drawings]

FIG. 1 is a sectional view of a semiconductor device according to a first embodiment of the present invention.

FIG. 2 is a sectional view of a semiconductor device according to a second embodiment of the present invention.

FIG. 3 is a cross-sectional view of a semiconductor device according to a modification of the second embodiment of the present invention.

FIG. 4 is a sectional view of a semiconductor device according to a third embodiment of the present invention.

FIG. 5 is a sectional view of a semiconductor device according to a fourth embodiment of the present invention.

FIGS. 6A to 6C are cross-sectional views illustrating respective steps of a method for manufacturing a semiconductor device according to the first embodiment of the present invention.

FIGS. 7A to 7C are cross-sectional views illustrating respective steps of a method for manufacturing a semiconductor device according to the first embodiment of the present invention.

FIGS. 8A to 8C are cross-sectional views illustrating respective steps of a method for manufacturing a semiconductor device according to a second embodiment of the present invention.

FIGS. 9A to 9C are cross-sectional views illustrating steps of a method for manufacturing a semiconductor device according to a second embodiment of the present invention.

FIGS. 10A to 10E are cross-sectional views illustrating respective steps of a method for manufacturing a semiconductor device according to a third embodiment of the present invention.

FIGS. 11A to 11C are cross-sectional views illustrating steps of a method for manufacturing a semiconductor device according to a fourth embodiment of the present invention.

FIGS. 12A to 12C are cross-sectional views illustrating steps of a method for manufacturing a semiconductor device according to a fourth embodiment of the present invention.

FIG. 13 is a sectional view of a conventional semiconductor device.

FIGS. 14A to 14E are cross-sectional views showing respective steps of a conventional method for manufacturing a semiconductor device.

[Explanation of symbols]

 Reference Signs List 10 semiconductor substrate 11 lower electrode 11A first platinum film 12 capacitance insulating film 12A ferroelectric film 13 upper electrode 13A second platinum film 14 interlayer insulating film 15 lower electrode contact hole 16 upper electrode contact hole 17 for diffusion prevention Conductive film 17A Titanium nitride film 18 Metal wiring 18a Titanium film 18b First titanium nitride film 18c Aluminum film 18d Second titanium nitride film 19 Resist pattern 20 Semiconductor substrate 21 Lower electrode 21A First platinum film 22 Capacitive insulating film 22A Strong Dielectric film 23 Upper electrode 23A Second platinum film 24 Interlayer insulating film 25 Lower electrode contact hole 26 Upper electrode contact hole 27 Diffusion preventing conductive film 27A Titanium nitride film 28 Metal wiring 28a Titanium film 28b First titanium nitride Film 28c aluminum film 28 Second titanium nitride film 29 Resist pattern 30 Semiconductor substrate 31 Lower electrode 31A First platinum film 32 Capacitive insulating film 32A Ferroelectric film 33 Upper electrode 33A Second platinum film 34 Interlayer insulating film 35 Lower electrode contact hole 36 Upper electrode contact hole 37 Diffusion preventing conductive film 37A Titanium nitride film 38 Metal wiring 38a Titanium film 38b First titanium nitride film 38c Aluminum film 38d Second titanium nitride film 40 Semiconductor substrate 41 Lower electrode 41A First platinum film 42 Capacitance insulating film 42A Ferroelectric film 43 Upper electrode 43A Second platinum film 44 Interlayer insulating film 45 Lower electrode contact hole 46 Upper electrode contact hole 47 Diffusion preventing conductive film 47A Titanium nitride film 48 Metal wiring 48a Titanium film 48b First titanium nitride film 48c Aluminum film 48d Second titanium nitride film 49 First resist pattern 50 Second resist pattern

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toyoji Ito 1-1, Sachimachi, Takatsuki-shi, Osaka Prefecture Inside Matsushita Electronics Corporation (72) Inventor Takumi Mikawa 1-1, Sachimachi, Takatsuki-shi, Osaka Matsushita Matsushita Electronics Corporation (72) Inventor Toru Nasu 1-1, Sachimachi, Takatsuki-shi, Osaka Prefecture Matsushita Electronics Corporation (72) Inventor Nohisa 1-1, Sachimachi, Takatsuki-shi, Osaka Prefecture (72) Inventor Keisuke Tanaka 1-1, Sachicho, Takatsuki-shi, Osaka Matsushita Electronics Corporation (72) Inventor Tomoe Kutsui 1-1, Sachimachi, Takatsuki-shi, Osaka Matsushita Electronics (56) References JP-A-9-97883 (JP, A) JP-A-8-17759 (JP, A) JP-A-8-264481 (JP, A) JP-A-8-288239 (JP, A A) JP-A-9-45877 (JP, A) (58) ) Field surveyed (Int.Cl. ⁶ , DB name) H01L 27/04 H01L 21/822 H01L 27/10 451

Claims (12)

(57) [Claims] A capacitor provided on the substrate, the capacitor including a capacitor lower electrode, a capacitor insulating film including an insulating metal oxide film, and a capacitor upper electrode; and a capacitor provided on the capacitor. An interlayer insulating film having an opening reaching the capacitor upper electrode; and a titanium film provided on the interlayer insulating film so as to be electrically connected to the capacitor upper electrode via the opening. A metal wiring, provided between the capacitor upper electrode and the metal wiring, for preventing titanium atoms forming a titanium film of the metal wiring from passing through the capacitor upper electrode and diffusing into the capacitor insulating film; A semiconductor device, comprising: a diffusion barrier film having conductivity. 2. The method according to claim 1, wherein the diffusion preventing film is a metal nitride film or a metal oxide film having conductivity.
3. The semiconductor device according to claim 1. 3. The semiconductor device according to claim 1, wherein the capacitance insulating film is a ferroelectric film or a high dielectric film. 4. The titanium film is provided below the metal wiring, is an adhesion layer for improving the adhesion between the metal wiring and the upper electrode, and the diffusion prevention film is a titanium nitride film. The semiconductor device according to claim 1, wherein: 5. The semiconductor device according to claim 1, wherein the capacitor upper electrode has a crystal structure having a crystal grain boundary. 6. A step of forming, on a substrate, a capacitive element composed of a capacitive lower electrode, a capacitive insulating film composed of an insulating metal oxide film, and a capacitive upper electrode; and forming the capacitive element on the capacitive element. Forming an interlayer insulating film having a contact hole reaching the upper electrode; and depositing a conductive film for preventing passage of titanium atoms over the entire surface of the interlayer insulating film including the contact hole. Patterning the conductive film so that at least a portion of the conductive film located inside the contact hole remains, forming a diffusion prevention film made of the conductive film; on the interlayer insulating film such that said diffusion barrier layer through the connected the capacitive upper electrode and electrically comprises a step of forming a metal wire having a titanium film, before Diffusion preventing film constitutes a titanium film of the metal wiring
Titanium atoms pass through the capacitor upper electrode and the capacitor insulation
A method for manufacturing a semiconductor device, comprising preventing diffusion into a film . 7. A step of sequentially depositing a first metal film, an insulating metal oxide film, a second metal film, and a conductive film for preventing passage of titanium atoms on a substrate; Patterning the metal film and the conductive film using the same etching mask to form a capacitor upper electrode made of the second metal film and a diffusion prevention film made of the conductive film; Patterning a film to form a capacitive insulating film, and patterning the first metal film to form a capacitive lower electrode; a capacitive element comprising the capacitive lower electrode, a capacitive insulating film, and a capacitive upper electrode Forming an interlayer insulating film having a contact hole reaching the capacitor upper electrode, and electrically connecting to the capacitor upper electrode via the diffusion preventing film on the interlayer insulating film. Like, And a step of forming a metal wiring having a down film, the diffusion barrier layer forms a titanium film of the metal wiring
Titanium atoms pass through the capacitor upper electrode and the capacitor insulation
A method for manufacturing a semiconductor device, comprising preventing diffusion into a film . 8. A step of forming a capacitor insulating film comprising a capacitor lower electrode and an insulating metal oxide film on a substrate, and forming a capacitor upper electrode on the substrate including the capacitor insulating film. Depositing an interlayer insulating film having an opening in a region to be formed, and over the entire surface of the interlayer insulating film including the opening,
A step of sequentially forming a metal film and a conductive film for preventing passage of titanium atoms; a step of forming a resist pattern on a portion of the conductive film corresponding to the opening; and a step of forming the metal film and the conductive film. The capacitor upper electrode and the conductive film made of the metal film are formed by performing dry etching using the resist pattern as a mask to leave a portion of the metal film and the conductive film located at the opening. Forming a diffusion prevention film consisting of: a titanium film on the interlayer insulating film after removing the resist pattern so as to be electrically connected to the capacitor upper electrode via the diffusion prevention film; Forming a metal wiring having the following formula : wherein the diffusion prevention film forms a titanium film of the metal wiring.
Titanium atoms pass through the capacitor upper electrode and the capacitor insulation
A method for manufacturing a semiconductor device, comprising preventing diffusion into a film . 9. The conductive film according to claim 6, wherein the conductive film is a metal nitride film or a metal oxide film having conductivity.
9. The method for manufacturing a semiconductor device according to claim 8. 10. The method according to claim 6, wherein the capacitor insulating film is a ferroelectric film or a high dielectric film. 11. The titanium film is provided below the metal wiring, is an adhesion layer for improving the adhesion between the metal wiring and the capacitor upper electrode, and the diffusion prevention film is a titanium nitride film. The method for manufacturing a semiconductor device according to claim 6, wherein: 12. The method according to claim 6, wherein the capacitor upper electrode has a crystal structure having a crystal grain boundary.