JP2912776B2 - 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 incorporating a large-capacitance element using a dielectric thin film having a high dielectric constant (hereinafter, referred to as a high dielectric thin film) as a capacitance insulating film, and a method of manufacturing the same.

[0002]

2. Description of the Related Art In recent years, high dielectric thin films have characteristics such as spontaneous polarization and high dielectric constant.
Access Memory) and highly integrated DRAM (Dynamic Random A)
Active research is being conducted with the aim of application as a capacitive insulating film on ccessMemory). A commonly used high dielectric thin film is formed of a sintered body of a metal oxide and contains a large amount of highly reactive oxygen. When a capacitive element is formed using such a high dielectric thin film, a platinum thin film that is stable against an oxidation reaction is indispensable as an upper electrode and a lower electrode.

Hereinafter, a conventional semiconductor device will be described. FIG. 5 is a sectional view of a main part of a conventional semiconductor device. FIG.
In the above, 1 is a supporting substrate, 2 is a first titanium thin film having a thickness of 10 to 100 nm, and 3 is a first titanium thin film having a thickness of 100 to 300 nm.
4 is a high dielectric thin film having a thickness of 100 to 300 nm, 5 is a second platinum thin film having a thickness of 100 to 300 nm, 7
Is a silicon oxide film as an interlayer insulating film, 8 is a contact hole, and 9 is an aluminum wiring.

As described above, in a conventional semiconductor device, a first platinum thin film 3 is an upper electrode, a high dielectric thin film 4 is a capacitor insulating film, and a first platinum thin film 4 is a capacitor insulating film on a supporting substrate 1 on which a semiconductor element or an integrated circuit is formed. A capacitive element using the platinum thin film 5 as a lower electrode is formed.

[0005]

However, in the above conventional structure, since the adhesion between the platinum thin film and the silicon oxide film is generally poor, the platinum thin film constituting the upper electrode occupying most of the area of the capacitor and the interlayer insulating film. However, there is a problem that separation easily occurs between the silicon oxide films.

An object of the present invention is to provide a semiconductor device having a capacitor element having improved adhesion between a platinum thin film and a silicon oxide film, and a method of manufacturing the same, which solves the above-mentioned conventional problems.

[0007]

In order to achieve this object, a semiconductor device according to the first aspect of the present invention comprises a semiconductor device and a semiconductor device.
Or a lower electrode and a capacitor on a support substrate on which an integrated circuit is formed.
High dielectric thin film to be an insulating film and upper electrode made of a platinum film
Is formed, and the capacitor is formed on the capacitor.
An insulating film made of a silicon oxide film is formed on
Through the contact hole formed in the insulating film.
Metal wiring is connected to the electrode and the lower electrode, respectively.
Between the upper electrode and the insulating film.
Metal oxide film is formed
Things. A semiconductor device according to claim 2 of the present invention.
Manufacturing method, a semiconductor element or an integrated circuit is formed
Forming a first metal thin film and a high dielectric thin film on a supporting substrate;
Forming the high dielectric thin film in an oxidizing atmosphere.
Heat treatment and heat treatment on the high dielectric thin film
A second metal thin film made of platinum and gold mainly containing titanium
Forming a metal oxide film sequentially; and
Metal oxide film, second platinum film, and high dielectric substance
Selectively leave the thin film capacitive element and leave the other parts
Removing and forming the upper electrode and the capacitor insulating film;
Removing the other portion while leaving the first metal thin film selectively
Step of forming a capacitive element by forming a lower electrode
Forming an insulating film over the entire surface of the capacitive element;
Of the insulating film and the metal oxide film containing titanium as a main component.
Forming a contact hole in a predetermined region;
Connect the contact hole to the upper electrode and the lower electrode
Forming a metal wiring,
Things.

[0008]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a main part of a capacitive element according to a first embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a support substrate on which an integrated circuit is formed, 2 denotes a Ti film having a thickness of 10 to 100 nm formed on the support substrate 1, and 3 denotes a Ti film.
Lower electrode having a thickness of 100 to 300 nm formed on the film 2
A Pt electrode 4 and a (Ba _x Sr _1-x ) TiO ₃ film having a thickness of 20 to 300 nm formed on the first Pt electrode 3,
5 is Pt which is a second upper electrode having a thickness of 100 to 300 nm.
Electrode , 6 is an insulating protective film, 7 is a contact hole provided in the insulating protective film 6, 8 is a metal wiring film made of an Al (1% Si-0.5% Cu) alloy, and 9 is a portion including the contact hole 7. Is a titanium tungsten (hereinafter abbreviated as TiW) film having a thickness of 5 to 150 nm.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A semiconductor device according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a main part of a semiconductor device according to a first embodiment of the present invention.
In FIG. 1, the same parts as those in the conventional example shown in FIG. The present embodiment differs from the conventional example shown in FIG. 5 in that a titanium thin film 6 is formed between a second platinum thin film 5 as an upper electrode and a silicon oxide film 7 as an interlayer insulating film. is there. As described above, the second platinum thin film 5 and the silicon oxide film 7 are in contact with each other via the titanium thin film 6 having good adhesion, so that peeling of the silicon oxide film 7 can be prevented.

Although the titanium thin film 6 is used in this embodiment, the same effect can be obtained by using a metal thin film containing titanium as a main component or a metal oxide film containing titanium as a main component.
There is no problem even if the silicon oxide film 7 of this embodiment contains an additive such as phosphorus or boron. Further, when an integrated circuit is formed on the support substrate 1 of the present embodiment, the silicon oxide film 7 is left only in a region for protecting the capacitive element, and is removed in other regions, thereby integrating with the aluminum wiring 9. A contact hole for connecting to a circuit can be easily formed. When an integrated circuit is formed on the support substrate 1, the support substrate 1 is, of course, a semiconductor substrate, and an interlayer insulating film is formed below the first titanium thin film 2.

Next, a manufacturing method for forming a semiconductor device according to a first embodiment of the present invention will be described with reference to the drawings.

FIGS. 2A to 2D are process sectional views of a method of manufacturing a semiconductor device according to a first embodiment of the present invention.
First, as shown in FIG. 2A, a first titanium thin film 2 is formed on a supporting substrate 1 on which an integrated circuit is formed by sputtering.
And a first platinum thin film 3 are sequentially formed. Next, a solution containing the constituent elements of the high dielectric thin film 4 is spin-coated by a sol-gel method, heated and dried in a nitrogen atmosphere at 200 to 400 ° C. for 1 to 5 minutes, and then dried in an oxygen atmosphere at 650 to 750 ° C. Baking at a high temperature for about 1 hour to form a high dielectric thin film 4. Further, a second platinum thin film 5 and a second titanium thin film 6 are sequentially formed by a sputtering method. Next, as shown in FIG.
Unnecessary portions of the second titanium thin film 6, the second platinum thin film 5, and the high dielectric thin film 4 are removed by using an ion milling method.
Next, as shown in FIG. 2C, the first platinum thin film 3 and the first titanium thin film take a larger area than the second titanium thin film 6, the second platinum thin film 5, and the high dielectric thin film 4. The unnecessary portion 2 is removed by using an ion milling method. Next, FIG.
As shown in (d), normal pressure CVD (Chemical Vapor Dep.
The silicon oxide film 7 is formed by an osition method. FIG. 2
(D) Although the subsequent steps are omitted, a contact hole 8 is further formed, and an aluminum wiring 9 is formed to obtain the semiconductor device shown in FIG.

Although an example in which the first titanium thin film 2, the first platinum thin film 3, the second platinum thin film 5, and the second titanium thin film 6 are formed by a sputtering method in the manufacturing process shown in FIG. 2, has been described. , EB vapor deposition method.

Next, a second embodiment of the present invention will be described with reference to the drawings. FIG. 3 is a sectional view of a main part of a semiconductor device according to a second embodiment of the present invention. In FIG. 3, the same parts as those in the conventional example shown in FIG. This embodiment is different from the conventional example shown in FIG. 5 in that the silicon oxide film 7 of the conventional example is
0 and the silicon oxide film 7. As described above, the first platinum thin film 3 and the second platinum thin film 5 are in contact with the silicon oxide film 7 via the titanium oxide film 10 having good adhesion, so that the silicon oxide film 7 can be prevented from peeling.

Next, a manufacturing method for forming a semiconductor device according to a second embodiment of the present invention will be described with reference to the drawings. FIGS. 4A to 4D are process cross-sectional views of a method of manufacturing a semiconductor device according to a second embodiment of the present invention. First, as shown in FIG. 4A, a first titanium thin film 2 and a first platinum thin film 3 are sequentially formed on a support substrate 1 in which an integrated circuit is formed by a sputtering method. Next, a solution containing the constituent elements of the high dielectric thin film 4 is spin-coated by a sol-gel method, dried by heating at 200 to 400 ° C. for 1 to 5 minutes in a nitrogen atmosphere, and dried at a high temperature of 650 to 750 ° C. in an oxygen atmosphere. For about 1 hour to form a high dielectric thin film 4. Further, a second platinum thin film 5 is formed by a sputtering method. Next, FIG.
As shown in (b), unnecessary portions of the first titanium thin film 6, the second platinum thin film 5, and the high dielectric thin film 4 are removed by using an ion milling method. Next, as shown in FIG. 4 (c), an unnecessary area of the first platinum thin film 3 and the first titanium thin film 2 is ion-milled by taking a larger area than the second platinum thin film 5 and the high dielectric thin film 4. Then, a second titanium thin film 10a is formed thereon by sputtering. Next, as shown in FIG.
Oxidized at a high temperature of 0 ° C. for about 30 minutes to form a second titanium thin film 10 a
Is converted into a titanium oxide film 10, and a silicon oxide film 7 is formed thereon by a normal pressure CVD method. Although the steps after FIG. 2D are omitted, a contact hole 8 is further formed,
By forming the aluminum wiring 9, the semiconductor device shown in FIG. 3 is obtained.

In this embodiment, the titanium oxide film 10 is formed by thermal oxidation after forming the second titanium thin film 10a by the sputtering method.
After forming a, the titanium oxide film 10 may be formed by thermal oxidation, or the titanium oxide film 10 may be formed directly by a CVD method.

[0017]

As described above, the present invention utilizes the property of titanium, which has good adhesion to both platinum and an insulating film, to form an insulating film on an upper electrode made of a platinum thin film via a titanium thin film. By forming the semiconductor device, a highly reliable semiconductor device which prevents separation at the interface between the platinum thin film and the insulating film and a method for manufacturing the same can be realized.

[Brief description of the drawings]

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

FIGS. 2A to 2D are process cross-sectional views of a method for manufacturing a semiconductor device according to a first embodiment of the present invention;

FIG. 3 is a sectional view of a main part of a semiconductor device according to a second embodiment of the present invention;

FIGS. 4A to 4D are process cross-sectional views of a method for manufacturing a semiconductor device according to a second embodiment of the present invention;

FIG. 5 is a sectional view of a main part of a semiconductor device in a conventional example.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 support substrate 3 first platinum thin film (lower electrode) 4 high dielectric thin film 5 second platinum thin film (upper electrode) 6 second titanium thin film (titanium thin film) 7 silicon oxide film (insulating film) 8 contact hole 9 Aluminum wiring (metal wiring)

Continuing on the front page (72) Inventor Yasuhiro Shimada 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture Inside Matsushita Denshi Kogyo Co., Ltd. References JP-A-3-54828 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01L 27/04 H01L 21/822 H01G 4/33 H01G 4/40

Claims (2)

(57) [Claims] 1. A semiconductor device or the lower electrode on a supporting substrate on which an integrated circuit is formed, and the capacitance element consisting of upper electrode made of a high dielectric thin film and platinum film serving as the capacitor insulating film is formed, the capacitor <br/> insulating film made of a silicon oxide film is formed on the element, and the metal wires are connected to each of the upper electrode and the lower electrode through the contact hole formed in the insulating film, the upper Electrodes and
A metal oxide film composed mainly of titanium is formed between the edge film
Semiconductor devices that are. 2. A step of forming a first metal thin film and a high dielectric thin film on a support substrate on which a semiconductor element or an integrated circuit is formed, and a step of heating the high dielectric thin film in an oxidizing atmosphere. And on the heat treated high dielectric thin film
A second metal thin film made of platinum and gold mainly containing titanium
Forming a metal oxide film sequentially; and
Metal oxide film, and forming the second metal thin film and the upper electrode and the capacitor insulating film said high a portion to be a capacitor dielectric thin film selectively left by removing the other portions, the first A step of forming a capacitive element by selectively removing the other metal thin film and removing the other part to form a lower electrode; and a step of forming an insulating film over the entire surface of the capacitive element .
The insulating film and the metal oxide film containing titanium as a main component
Forming a contact hole in a predetermined region of
The contact hole passes through the upper electrode and the lower electrode.
Forming a metal wiring .