JPH06283606A - Semiconductor device and its manufacture - Google Patents

Abstract

PURPOSE:To control preferential crystal orientation of an upper layer wiring, flatten a wiring layer, realize a wiring of high reliability, and simplify a process, by a method wherein a titanium nitride film which turns to barrier metal, is excellent in coverage, and has specific orientation is formed, while filling connection holes in order to connect a lower layer wiring with the upper layer wiring. CONSTITUTION:In a conductive region on a semiconductor substrate 1 or in a contact part containing connection holes for connecting a lower layer wiring with an upper layer wiring, a titanium nitride film 4 which is excellent in coverage and oriented in (200) is formed with an excellent coverage to the contact part. After that, on the surface of (200) oriented titanium nitride 4, a thin film layer 7 for changing the orientation of TiN from (200) to (111) is formed with a coverage of 50% or larger, and a (111) oriented TiN film 5 is again formed. Thereby an Al based alloy wiring excellent in EM resistance and flatness can be obtained.

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 a method of manufacturing the same, and more particularly, to a semiconductor substrate or a lower layer wiring and a connection hole between the upper layer wiring and the upper layer wiring while controlling the preferential crystal orientation of the upper layer wiring. The present invention relates to a semiconductor device that connects lower layers and a manufacturing method thereof.

[0002]

2. Description of the Related Art Conventionally, in order to connect a semiconductor substrate or a lower layer wiring (hereinafter, typically referred to as a lower layer wiring) and an upper layer wiring, a connection hole (contact hole or viewer) is formed in an interlayer insulating film interposed between both layers. It has been practiced to open and directly bury this connection hole with an upper layer wiring material, or to bury an upper layer wiring after burying with a conductive film. Here, aluminum (Al) is often used as a wiring material.

On the other hand, as semiconductor devices become finer and more highly integrated, problems such as spikes of aluminum, which is a wiring material, in the diffusion layer and deposition of substrate silicon on aluminum wiring have arisen in shallow diffusion layers. Therefore, it is necessary to use 1
%, An aluminum alloy mixed with silicon is used, and a diffusion barrier layer (called a barrier metal) is used to prevent mutual diffusion of aluminum and silicon in a contact portion between the aluminum alloy and the silicon diffusion layer. . This is the same when burying the connection hole, that is, when forming the plug.

Titanium nitride (titanium nitride) is currently considered to be the most promising material for barrier metals.
Is. Titanium nitride (TiN) has not only excellent barrier properties but also relatively low resistance, and titanium silicide, which is the same titanium compound, can easily realize low resistance contact with a silicon substrate for film formation. The reason is that it has continuity and that it has excellent adhesion to tungsten when a tungsten plug is applied to the contact hole.

The electromigration (EM) resistance of aluminum or aluminum alloy wiring is (11)
It is said that the film oriented in 1) is excellent, and as a method therefor, JP-A-3-262127 discloses T film.
A method is disclosed in which the iN film is oriented in (111) and an Al wiring layer having (111) orientation is formed thereon.

On the other hand, as a contact plug for burying a connection hole, a technique of simply burying a CVD-TiN plug instead of a tungsten (W) plug using TiN as a barrier metal is Abstract of the 1991 International.
Conference on Solid State Devices and Materials, Y
okohama, 1991, pp. 210-212.

[0007]

By the way, JP-A-3-
In Japanese Patent Laid-Open No. 262127, a (111) -oriented TiN film, which is a barrier metal having barrier properties and high reliability, is disclosed as follows.
There is a problem that it is not suitable for forming a contact plug because it is formed by directly depositing Ti by sputtering and then nitriding it or by reactive sputtering.

However, when titanium nitride is formed by the conventional CVD method, the film quality that can be used for wiring is obtained when it is oriented in (200).
It has been reported that a titanium nitride film oriented in (111) has a poor function as a diffusion barrier layer which is an essential purpose of a barrier metal.

In the above-mentioned method of filling a contact hole with CVD-TiN, no consideration is given to the orientation of TiN, which is the filling material. Therefore, considering the coating property, the conventional CVD-TiN has a T orientation of (200).
Since it is embedded with iN, the film quality is good and it is suitable for wiring, but the orientation of Al, which is the wiring material in the upper layer, is also (200), and the orientation of (111) does not occur, so the reliability of the wiring is improved. There was a problem of lowering. on the other hand,
When TiN oriented to (111) is formed by the CVD method and the contact hole is filled, CVD-TiN
The film quality of (111) cannot be said to be sufficient, and there was a problem that the wiring resistance increased and the barrier property deteriorated.

That is, the conventional CVD for contact-
The TiN technique has not been a technique that takes into consideration the formability of an alignment film in which Al to be stacked has good EM resistance. This cause is advantageous for the formation of a (111) oriented film of Al.
1) When the oriented CVD-TiN is realized, the covering property generally tends to deteriorate. Therefore, (1
11) It was difficult to achieve good coverage with oriented CVD-TiN.

An object of the present invention is to eliminate the above-mentioned problems of the prior art and to connect a semiconductor substrate or a lower layer wiring to an upper layer wiring, by filling the connection hole between the upper and lower wiring layers with aluminum or its alloy. By forming a (111) oriented titanium nitride film having good coverage as a barrier metal having both a diffusion barrier property and a high reliability of the wiring as a base of the upper wiring, the preferential crystal orientation of the upper wiring is controlled to It is an object of the present invention to provide a semiconductor device in which a layer is flattened, highly reliable wiring is realized, and a process is simplified, and a manufacturing method thereof.

[0012]

In order to achieve the above-mentioned object, the present inventors diligently studied the orientation and the covering property of titanium nitride used as a barrier metal under the aluminum or its alloy wiring in the upper layer. As a result, in the surface reaction and the supply reaction that control the coating property, even under the process conditions of the surface reaction region, the conventional silicon or silicon oxide has a (200) orientation, but on the Ti (002) ( The present invention has been completed by finding that the (111) orientation is achieved.

That is, the first aspect of the present invention is to form a conductive region on a semiconductor substrate or a connection hole for connecting a lower layer wiring and an upper layer wiring on the conductive region or the lower layer wiring on the bottom surface of the connection hole. (200) oriented first titanium nitride film and a thin film or grain for controlling the crystal orientation of the second titanium nitride film formed on the first titanium nitride film with a surface coverage of 50% or more. And (111) by this thin film or grain laminated on this thin film or grain
A semiconductor device comprising: a second titanium nitride film oriented in a vertical direction; and an aluminum film or an alloy film thereof which composes the upper wiring layer and is laminated on the second titanium nitride film. Is.

In a second aspect of the present invention, the semiconductor substrate or the lower layer wiring and the upper layer wiring are connected through a connection hole between the conductive region or the lower layer wiring on the semiconductor substrate and the upper layer wiring made of aluminum or an alloy thereof. In manufacturing a semiconductor device by connecting with wiring, first, on a conductive region of the semiconductor substrate on the bottom surface of the connection hole or on a lower wiring (200).
(200) oriented titanium nitride under the condition of
Deposited by the VD method to fill the whole of the contact hole or cover the bottom surface and side surface of the contact hole;
0) oriented first titanium nitride film is formed, and then
A second (111) -oriented second film is formed on the first titanium nitride film.
Of the thin film effective for forming the titanium nitride film or the second titanium nitride film scattered on the first titanium nitride film as a nucleus growth center is coated with a surface coverage of 50% or more, and then the CVD method is used. Under the same conditions, after forming a second titanium nitride film oriented to (111) effective for making the orientation of aluminum or its alloy forming the upper wiring layer to be (111), the second titanium nitride film is formed. The present invention provides a method for manufacturing a semiconductor device, which comprises laminating aluminum or an alloy film thereof that constitutes the upper wiring layer on a titanium nitride film.

Further, a third aspect of the present invention is that the semiconductor substrate or the lower layer wiring and the upper layer wiring are connected via a connection hole between the conductive region or the lower layer wiring on the semiconductor substrate and the upper layer wiring made of aluminum or its alloy. In manufacturing a semiconductor device by connecting with wiring, first, on a conductive region of the semiconductor substrate on the bottom surface of the connection hole or on a lower wiring (200).
(200) -oriented titanium nitride is deposited by a CVD method under the condition of orienting to form a first titanium nitride film oriented to (200) beyond the upper edge of the connection hole, and then, After etching back the first titanium nitride film laminated on the upper edge of the contact hole, subsequently, it is effective for forming a (111) -oriented second titanium nitride film on this first titanium nitride film. A thin film or a grain of the second titanium nitride film which is scattered and becomes the nucleus growth center with a surface coverage of 50% or more, and then the orientation of the aluminum or its alloy forming the upper wiring layer is set to (111). Valid for (1
11) A second titanium nitride film oriented to form a second titanium nitride film, and thereafter, aluminum or an alloy film forming the upper wiring is laminated on the second titanium nitride film, and a method of manufacturing a semiconductor device. Is provided.

Here, the thin film or grain, the second titanium nitride film and aluminum or its alloy film are
It is preferably formed by the sputter method. Further, in each of the above aspects, it is preferable that the thin film or grain is titanium.

A fourth aspect of the present invention is that the semiconductor substrate or the lower layer wiring and the upper layer wiring are connected via a connection hole between the conductive region or the lower layer wiring on the semiconductor substrate and the upper layer wiring made of aluminum or an alloy thereof. In manufacturing a connection semiconductor device with wiring, first, titanium nitride oriented in (200) is CVD on a conductive region of the semiconductor substrate on the bottom surface of the connection hole or on lower wiring under the condition of (200) orientation.
To form a (200) -oriented first titanium nitride film that is deposited by a method to fill the entire connection hole or cover the bottom surface and side surface of the connection hole, and then form the first titanium nitride film. A titanium film effective for forming a (111) -oriented second titanium nitride film is formed on the film, and then a part of the titanium film is subjected to a nitriding treatment to form a (111) -oriented second nitride film. A method for manufacturing a semiconductor device is provided, which comprises forming a titanium film and then laminating aluminum or its alloy film forming the upper wiring layer on the second titanium nitride film.

[0018]

According to the semiconductor device and the method of manufacturing the same of the present invention, in the contact region including the conductive region on the semiconductor substrate or the connection hole for connecting the lower wiring and the upper wiring,
After forming a (200) oriented titanium nitride (TiN) film having excellent covering properties on the contact portion with good covering properties, a thin film layer for changing the TiN orientation property to (111) is formed once, and again, A semiconductor device having a wiring connection structure formed by forming a TiN (111) orientation film to fill a contact portion and form an upper layer aluminum (Al) or its alloy (hereinafter referred to as Al alloy) wiring It is a manufacturing method. At this time, since the Al-based alloy wiring is oriented in (111), excellent EM resistance can be realized. The thin film layer for changing the orientation of TiN may be thin film titanium as long as the surface coverage is 50% or more, or titanium particles (atoms) may be scattered and deposited. The present invention can be applied not only to the contact with the semiconductor substrate but also between the multilayer metal wirings. Similar effects can be obtained even when the surface of the semiconductor substrate is silicidized.

In the method of manufacturing a semiconductor device according to the second aspect of the present invention, a part or all of the contact portion is formed by CVD.
Thin film layer that changes the orientation of TiN after being coated or embedded with TiN (200) by the CVD method at a surface coverage of 50% or more, and again by the CVD method under the same conditions.
11) An alignment film is formed, and an upper Al-based alloy wiring layer is formed by, for example, a CVD method or a sputtering method. Also,
In the third aspect of the present invention, the contact portion is entirely filled with TiN (200) by a CVD method, and then etched back to be flattened, and the TiN orientation control thin film layer, TiN ( 111) and an Al-based alloy wiring layer are formed. Furthermore, in the fourth aspect of the present invention, TiN (20
After depositing (0), a Ti film is laminated, a part of the front surface side of the Ti film is nitrided to form TiN (111), and then an Al-based alloy wiring layer is deposited.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A semiconductor device and a method of manufacturing the same according to the present invention will be described in detail with reference to the preferred embodiments shown in the accompanying drawings.

1 (a), (b), (c) and (d)
3A and 3B are schematic cross-sectional structure diagrams illustrating examples of the semiconductor device according to the first aspect of the present invention. In the following examples, the first conductivity type silicon substrate as the lower semiconductor substrate,
Titanium (Ti) as the material of the thin film that changes the orientation of TiN to (111), and aluminum (Al) as the upper wiring.
The case of using is described as a representative example, but it goes without saying that the present invention is not limited to this.

The structure of the contact portion of one embodiment of the semiconductor device of the present invention shown in FIG. 1A is obtained by the method of manufacturing a semiconductor device of the second aspect of the present invention. , There is a high-concentration diffusion layer region 2 of the opposite conductivity type formed on the first-conductivity-type silicon substrate 1, and an interlayer insulating film (for example, BPSG) 3 on this high-concentration diffusion layer region 2 is opened. Aluminum 6 and titanium nitride (11
1) There is a connection hole for electrically connecting the high-concentration diffusion layer 2 and the upper wiring layer having the elements 5, 5, 7 and titanium nitride (200) 4. The silicon high-concentration diffusion layer 2 on the bottom surface of the connection hole, the side surface, and the peripheral surface of the insulating film 3 have good coverage, good film quality, and effective barrier properties (2
00) Oriented titanium nitride 4 is coated and laminated. Further, this connection hole is mainly filled with titanium nitride 5 preferentially oriented in (111), and the insulating film 3 is formed from the connection hole portion.
It is formed over. Aluminum 6 having a (111) orientation is formed on the titanium nitride 5. Also, on the (200) oriented titanium nitride 4, titanium nitride 5
At least titanium 7, which is effective for promoting the (111) preferential orientation of titanium nitride, exists on the surface of the (200) oriented titanium nitride 4 at a coverage of at least 50% or more. Although the high-concentration diffusion layer 2 is shown here,
Similar effects can be obtained even if the substrate surface is silicidized in advance. Further, when the titanium layer 7 is a continuous film, the (002) crystal orientation has the effect of further promoting the (111) crystal orientation of titanium nitride.

The structure of the contact portion of the semiconductor device of the present invention shown in FIG. 1B is obtained by the method of manufacturing a semiconductor device according to the second and fourth aspects of the present invention. In this embodiment, There is a high-concentration diffusion layer region 2 of the opposite conductivity type formed on a first-conductivity-type silicon substrate 1. An insulating film 3 on this high-concentration diffusion layer region 2 is opened to form aluminum 6 and titanium nitride ( 111) 5, titanium 7 and titanium nitride (200) 4 are provided as connection holes for electrically connecting the upper wiring layer and the high concentration diffusion layer 2. The (200) oriented titanium nitride 4 having good coverage, good film quality, and effective barrier properties is coated and laminated on the silicon high-concentration diffusion layer 2 on the bottom surface of the connection hole, the side surface, and the peripheral surface of the insulating film 3. ing. The connection hole is mainly filled with (6 1 1) -oriented aluminum 6 and is formed from the connection hole portion to the insulating film 3. Titanium nitride 5 having a (111) orientation is formed on the base of this aluminum 6. Further, at least titanium 7, which is effective for promoting the (111) preferred orientation of titanium nitride, is present on the surface of the titanium nitride 5 on the surface of the (200) oriented titanium nitride 4 at a coverage of at least 50% or more. . Here, the high-concentration diffusion layer 2 is shown, but in advance,
Similar effects can be obtained even if the substrate surface is silicidized. Further, when the titanium layer 7 is a continuous film, the (002) crystal orientation has the effect of further promoting the (111) crystal orientation of titanium nitride.

The structure of the contact portion shown in FIG.
It is obtained by the method for manufacturing a semiconductor device according to the second and fourth aspects of the present invention, and in this embodiment, a high-concentration diffusion layer region of the opposite conductivity type formed on the silicon substrate 1 of the first conductivity type. 2 and the interlayer insulating film (for example, BPS) 3 on this high-concentration diffusion layer region 2 is opened to form aluminum 6, titanium nitride (111) 5, titanium 7, and titanium nitride (200) 4. There is a connection hole for electrically connecting the upper wiring layer as an element and the high-concentration diffusion layer 2, and the coverage on the surface of the silicon high-concentration diffusion layer 2 on the bottom surface and the side surface and the peripheral insulating film 3 is high. Well, it is completely filled with (200) oriented titanium nitride 4 having good film quality and effective barrier property, and is formed from the connection hole portion to the insulating film 3. In addition, titanium nitride (20
0) 4 is at least titanium 7 effective as a base of titanium nitride (111) 5 for promoting the (111) preferential orientation of titanium nitride, and at least 50% of titanium 7 on the surface of (200) oriented titanium nitride 4. It exists with the above coverage.
The titanium nitride 5 preferentially oriented in (111) is formed on the titanium 7, and the aluminum 6 oriented in (111) is formed on the titanium nitride (111) 5. Although the high-concentration diffusion layer is shown here, in advance,
Similar effects can be obtained even if the substrate surface is silicidized. Further, when the titanium layer 7 is a continuous film, the (002) crystal orientation has the effect of further promoting the (111) crystal orientation of titanium nitride.

Next, specific examples of the manufacturing method for each example of the semiconductor device of the present invention having the contact portion structure shown in FIGS. 1 (a), 1 (b), 1 (c) and 1 (d) will be described. 2, which will be specifically described with reference to the process charts shown in FIGS.

2A to 2D and 2E are shown in FIG.
FIG. 6 is a schematic sectional view of a contact portion showing each step in one embodiment of the method for manufacturing a semiconductor device according to the second aspect of the present invention for obtaining the contact portion structure shown in FIG. As shown in FIG. 2A, a high-concentration diffusion layer region 2 of the opposite conductivity type is formed on the silicon substrate 1 of the first conductivity type.
Had been formed. Interlayer insulating film 3 made of silicon oxide
Is formed on the substrate 1 to a thickness of about 1 μm, and the high concentration diffusion layer region 2 is formed.
After the upper insulating film 3 was patterned, it was removed by dry etching, and a 0.2 μm diameter connection hole was opened.

Next, as shown in FIG. 2B, CVD
Titanium nitride 4 oriented to (200) by the method is formed on the surface of the high-concentration diffusion layer 2 on the bottom surface of the connection hole and on the side surface of the insulation film 3 on the side surface of the connection hole and on the upper surface of the insulation film 3 outside the connection hole.
Only the thickness of 02 μm was formed. At this time, the film formation conditions of the titanium nitride 5 are as follows: vacuum degree 0.1 Torr, substrate heating temperature 650 ° C., T
The iCl ₄ vapor was 2 sccm, and the flow rates of ammonia gas and hydrogen gas were both 10 sccm. This condition was a condition that the preferential crystal orientation of titanium nitride 4 was (200) when formed on silicon or silicon oxide. (20
0) The coverage of the oriented titanium nitride 4 was good. By the way, the film thickness of the (200) oriented titanium nitride film formed by the CVD method may be 5 nm or more. Then, as shown in FIG. 2C, the titanium film 7 is sputtered to form titanium nitride (20
0) formed on 4. Titanium 7 was formed on titanium nitride (200) 4 in a flat portion outside the connection hole to a thickness of 5 nm.
Further, titanium 7 was formed with a coverage of 50% or more on the bottom surface of the connection hole corresponding to the high-concentration diffusion layer 2.

Then, in FIG. 2D, titanium nitride 5 is removed.
Formed on tongue 7. Film forming conditions of titanium nitride 5 at this time
Is vacuum 0.1 Torr, substrate heating temperature 650 ° C., Ti
Cl _Four2 sccm of vapor, ammonia gas and hydrogen gas
The flow rate of the gas was 10 sccm. This condition is
Preferred crystal orientation of titanium nitride 5 when formed on silicon nitride
Is titanium (200), but titanium 7 is formed in advance.
As a result, due to the effect of titanium 7, (111) has priority.
The crystal was oriented. In addition, the coverage is good and the formed film thickness is
By setting the thickness to 0.1 μm, the connection hole is made of titanium nitride 5.
I was able to embed more. Finally, in FIG.
Luminium 6 is sputtered on titanium nitride 5
0.8 μm was formed. Titanium nitride 5 has priority over (111)
Crystallographically oriented, aluminum 6 is also (111)
Preferred crystal orientation. This aluminum 6 / titanium nitride
5 / Titanium 7 upper wiring layer is patterned
And became the upper layer wiring. Here, titanium 7 is not a continuous film.
At least, it has a certain degree of coverage (50%) or more.
If it is made of titanium nitride 5 (111),
Preferred crystal orientation.

Here, the conductive region of the semiconductor substrate or the lower layer wiring is coated with the thin film or the nucleus growth center grain or atom at a coverage of 50% or more when the TiN (111) is coated at a coverage of 50% or more. The reason is that a good preferential crystal orientation of (1) can be obtained.

Here, the high-concentration diffusion layer 2 is shown, but the same effect can be obtained even if the substrate surface is silicidized in advance. Further, when the titanium layer is a continuous film, the (002) crystal orientation has the effect of further promoting the (111) crystal orientation of titanium nitride. The aluminum 6 can be formed by the CVD method, and in this case as well, since the (111) oriented titanium nitride 5 is used as the base, it is oriented in (111).

As shown in FIG. 2E, in the second embodiment of the present invention, after the titanium 7 shown in FIG. 2C is formed, nitriding is performed by the CVD method under the same film forming conditions. By setting the film thickness of titanium (111) 5 to 0.05 μm, a sufficient preferential crystal orientation can be obtained, and aluminum 6 is deposited on titanium nitride 5 by a CVD method at a total pressure of 1 Torr.
At 250 ° C. (CH ₃ ) ₂ AlH was introduced into the chamber with H ₂ carrier to form about 0.8 μm, and the connection hole could be completely filled with aluminum 6. Also in this case, the titanium nitride 5 having a thickness of 0.05 μm is sufficiently (1
11) is preferentially crystallized, and aluminum 6 is similarly preferentially crystallized in (111). This aluminum 6
The upper wiring layer composed of / titanium nitride 5 / titanium 7 could be patterned to form an upper wiring. Thus
The structure of the contact portion shown in FIG. 1B was obtained. In this case, (111) oriented titanium nitride 5
May be formed by a sputtering method.

FIGS. 3 (a) to 3 (d) show the steps of a contact portion in another embodiment of the first wiring connection method of the present invention for obtaining the structure of the contact portion shown in FIG. 1 (c). It is shown by the schematic cross-sectional structure diagram of FIG. As shown in FIG. 3A, a high-concentration diffusion layer region 2 of the opposite conductivity type was formed on the silicon substrate 1 of the first conductivity type. An interlayer insulating film 3 made of silicon oxide is formed on the substrate 1 to a thickness of about 1 μm, and the insulating film 3 on the high-concentration diffusion layer region 2 is patterned and then removed by dry etching.
A m-diameter connection hole was opened.

Next, as shown in FIG. 3B, CVD
By the method, titanium nitride 4 oriented in (200) was formed on the surface of the high-concentration diffusion layer 2 on the bottom surface of the connection hole, the surface of the insulating film 3 on the side surface of the connection hole, and the upper surface of the insulating film 3 outside the connection.
By setting the film thickness to 0.1 μm, the connection hole could be completely filled. At this time, the titanium nitride 5 film formation conditions are as follows:
Vacuum degree 0.1 Torr, substrate heating temperature 650 ° C, TiC
The l ₄ vapor was 2 sccm, and the flow rates of ammonia gas and hydrogen gas were both 10 sccm. This condition was a condition that the preferential crystal orientation of titanium nitride 4 was (200) when formed on silicon or silicon oxide. The coverage of the (200) oriented titanium nitride 4 was good. Then, FIG.
As shown in (c), a titanium film 7 was formed on the (200) oriented titanium nitride 4 by sputtering. Titanium 7 was formed on titanium nitride 4 in a thickness of 5 nm. here,
Titanium 7 was also formed on the bottom surface of the connection hole with a coverage of 50% or more.

Next, in FIG. 3 (d), titanium nitride 5 is checked.
Formed on tongue 7. Film forming conditions of titanium nitride 5 at this time
Is vacuum 0.1 Torr, substrate heating temperature 650 ° C., Ti
Cl _Four2 sccm of vapor, ammonia gas and hydrogen gas
The flow rate of the gas was 10 sccm. This condition is
Preferred crystal orientation of titanium nitride 5 when formed on silicon nitride
Is titanium (200), but titanium 7 is formed in advance.
As a result, due to the effect of titanium 7, (111) has priority.
The crystal was oriented. In addition, the coverage is good and the formed film thickness is
It was 0.05 micron. 0.05 micron
Was sufficient (111) preferential crystal orientation. Figure 3 (d)
Then aluminum 6 is sputtered to titanium nitride 5
Formed about 0.8 microns on top. Titanium nitride 5 is (11
The preferred crystal orientation is 1), and aluminum 6 is
The preferred crystal orientation was (111). This aluminum 6 /
The upper wiring layer consisting of titanium nitride 5 / titanium 7 is a pattern
And became an upper layer wiring. Here, titanium 7 is
Even if it is not a continuous film, the above-mentioned constant (50%) or more coverage
If it is formed by holding, the titanium nitride 5
Preferential crystal orientation is (111).

Here, the high-concentration diffusion layer 2 is shown, but the same effect can be obtained even if the substrate surface is silicidized in advance. Further, when the titanium layer is a continuous film, the (002) crystal orientation has the effect of further promoting the (111) crystal orientation of titanium nitride.

3 (a), (b), (e) and (f),
Another embodiment of the wiring connection method according to the third aspect of the present invention for obtaining the structure of the contact portion shown in FIG.
Each step is shown by a schematic sectional structure of a contact portion. The steps shown in FIG. 3A and FIG.
Since the wiring connection method of the second aspect of the present invention has been described, the description thereof will be omitted. As shown in FIG. 3B, the (200) oriented titanium nitride 4 was used to completely fill the contact hole, and then the titanium nitride 4 was etched back with Cl ₂ gas as shown in FIG. Ti8 / Ti by sputter method
N9 / Al10 was laminated. The sputtered TiN9 on the sputter Ti8 has a (111) preferential crystal orientation,
Similarly, spatter Al (aluminum) 10 (11
The preferred crystal orientation was 1). The upper wiring layer 11 made of aluminum 10 / titanium nitride 9 / titanium 8 is patterned to be an upper wiring. Here, if the titanium 8 is not a continuous film but is formed with a coverage of 50% or more, the titanium nitride 9 is preferentially crystallized in (111).

Here, the high-concentration diffusion layer 2 is shown, but the same effect can be obtained even if the substrate surface is previously silicidized. Further, in the case where the titanium layer 8 is a continuous film, the (002) crystal orientation has the effect of further promoting the (111) crystal orientation of the titanium nitride 9.

In the wiring connecting method of the fourth aspect of the present invention, after the titanium film 7 is formed to a thickness of 0.05 μm in the steps of FIGS. 2 is formed by performing a nitriding treatment (RTA treatment (rapid heating treatment) in nitrogen gas) on a part of the (111) oriented titanium nitride 5, as shown in FIG. 2E, that is, FIG. 1B and FIG. (D) That is, the contact portion having the structure shown in FIG. 1C can be obtained. Here, this nitriding treatment condition is N
A lamp anneal of H ₃ 1000 sccm, 800 ° C., 30 sec can be performed.

In the embodiment described above, the semiconductor substrate 1
Of the conductive region 2 and the upper wiring layer of aluminum 6
Although the wiring connection method in the connection hole between the upper layer wiring and the lower layer wiring has been described, the present invention is not limited to this, and is applied to the connection hole between the lower layer wiring and the upper layer wiring in the multi-genus metal wiring made of Al or the like. May be. Further, although Al has been described as a typical example of the metal constituting the upper layer wiring and the lower layer wiring, the present invention is not limited to this, and an Al alloy, C
You may use u, Cu alloy, etc.

In the above embodiment, the first and second TiN films are formed by the CVD method, and the TiCl ₄ / NH ₃ / H ₂ system is used as the raw material system for the CVD. The present invention is not limited to this, and even in the formation of the TiN film, if the raw material system is a system containing a titanium compound,
There is no particular limitation, and for example, titanium halides such as TiBr ₄ and TiI ₄ and organic compounds such as diethylamino titanium can be used. Further, the TiN film forming conditions of CVD are not limited to those in the above-mentioned embodiment,
Any conditions may be used as long as TiN having a good film quality is directly formed on the semiconductor substrate, for example, TiCl ₄ / NH ₃
/ H ₂ system, substrate temperature 650 to 750 ℃, TiCl ₄
And NH ₃ partial pressure ratio of 1: 1 to 1:25, NH ₃ and H ₂ partial pressure ratio of 1: 0 to 1: 1 and total pressure of 10 mTorr to 10
It can be Torr. In addition, CVD-Al (1
The film forming conditions of 11) are not limited to those in the above embodiment.

In the above embodiment, the (111) orientation T
Although Ti7 and 8 were coated as a thin film on the underlayer of the iN films 5 and 9 by the sputtering method,
There is no particular limitation on the method of coating the (002) orientation T
Any method may be used as long as i7 and i8 can be coated on the (200) oriented TiN film 4 at a surface coverage of 50% or more. Further, in the above-mentioned embodiment, the (002) oriented Ti7 is the nucleation at the initial stage of film formation that determines the orientation of the CVD-TiN5, that is, Ti which becomes the (111) oriented in the future.
It is used for nucleation of N.

In the above example, Ti is used as the material of the thin film, but the present invention is not limited to this.
Any material may be used as long as the orientation of the TiN 5 or 9 film can be controlled to favorably control the orientation of the aluminum alloy wiring.

[0043]

As described above in detail, according to the semiconductor device and the method of manufacturing the same of the present invention, the barrier property is effective while filling the connection hole between the semiconductor substrate or the lower layer wiring and the upper layer wiring (200). ) Promote the (111) orientation of the oriented titanium nitride film and the upper aluminum-based alloy wiring (11)
1) Oriented titanium nitride film (especially CVD-TiN (11
Since 1) films can be laminated, not only the wiring can be flattened, but also highly reliable wiring can be formed.

[Brief description of drawings]

1 (a), (b), (c) and (d) are cross-sectional views showing a structure of each embodiment of a connection hole portion of a semiconductor device according to the present invention.

2A to 2D are process diagrams of an embodiment of a method for manufacturing a semiconductor device of the present invention.

3A to 3D are process diagrams of another embodiment of the method for manufacturing a semiconductor device of the present invention.

[Explanation of symbols]

 1 1st conductivity type silicon substrate 2 Opposite conductivity type high concentration diffusion layer 3 Interlayer insulation film 4 CVD-TiN (200) 5 CVD-TiN (111) 6 Al (111) 7 Ti 8 Sputtered Ti 9 Sputtered TiN 10 Sputtered Al 11 Upper layer wiring (Ti / TiN / Al laminated wiring)

Claims (6)

[Claims] 1. A connection hole for connecting a conductive region on a semiconductor substrate or a lower layer wiring to an upper layer wiring is formed on the conductive region or the lower layer wiring on the bottom surface of the connection hole (20).
0) oriented first titanium nitride film, and a thin film or grain for controlling the crystal orientation of the second titanium nitride film formed on the first titanium nitride film with a surface coverage of 50% or more, A second titanium nitride film oriented in (111) by the thin film or grains laminated on the thin film or grains, and aluminum constituting the upper wiring layer laminated on the second titanium nitride film, or A semiconductor device having the alloy film. 2. A semiconductor device in which the semiconductor substrate or the lower layer wiring is connected to the upper layer wiring through a connection hole between a conductive region or a lower layer wiring on the semiconductor substrate and an upper layer wiring made of aluminum or its alloy. In manufacturing, first, under the condition of (20) orientation on the conductive region of the semiconductor substrate on the bottom surface of the connection hole or on the lower wiring (20)
0) oriented titanium nitride is deposited by the CVD method,
A (200) -oriented first titanium nitride film is formed which fills the whole of the connection hole or covers the bottom surface and side surface of the connection hole, and then forms (111) on the first titanium nitride film. A thin film effective for forming the second titanium nitride film oriented in the direction of or a grain serving as a nucleus growth center of the second titanium nitride film scattered on the first titanium nitride film is coated with a surface coverage of 50% or more. Then, the orientation of aluminum or its alloy forming the upper wiring layer is changed to (11
After forming a second titanium nitride film oriented in (111) effective for 1), aluminum or its alloy film forming the upper wiring layer is laminated on the second titanium nitride film. A method of manufacturing a semiconductor device, comprising: 3. A semiconductor device in which the semiconductor substrate or the lower layer wiring is connected to the upper layer wiring through a connection hole between a conductive region or the lower layer wiring on the semiconductor substrate and the upper layer wiring made of aluminum or its alloy. In manufacturing, first, CVD is performed under the condition of (200) orientation on the conductive region of the semiconductor substrate on the bottom surface of the connection hole or on the lower wiring.
Deposition of titanium nitride oriented in (200),
A first (200) oriented beyond the upper edge of the connection hole
Of the titanium nitride film is formed, and then the first titanium nitride film laminated on the upper edge of the connection hole is etched back. Subsequently, the (111) orientation is formed on the first titanium nitride film. The thin film effective for forming the second titanium nitride film described above or the grains serving as the nucleus growth centers of the scattered second titanium nitride film are coated with a surface coverage of 50% or more, and then aluminum or the upper wiring layer is formed. It is effective to make the orientation of the alloy to (111) (11
A method for manufacturing a semiconductor device, comprising forming a second titanium nitride film oriented in 1) and then laminating aluminum or an alloy film thereof forming the upper wiring on the second titanium nitride film. . 4. The method of manufacturing a semiconductor device according to claim 3, wherein the thin film or grain, the second titanium nitride film and the aluminum or its alloy film are formed by a sputtering method. 5. The method of manufacturing a semiconductor device according to claim 1, wherein the thin film or grain is titanium. 6. A semiconductor device in which the semiconductor substrate or the lower layer wiring and the upper layer wiring are connected through a connection hole between a conductive region or a lower layer wiring on the semiconductor substrate and an upper layer wiring made of aluminum or an alloy thereof. At this time, first, under the condition of (20) orientation on the conductive region of the semiconductor substrate on the bottom surface of the connection hole or on the lower wiring,
0) oriented titanium nitride is deposited by the CVD method,
A (200) -oriented first titanium nitride film is formed which fills the whole of the connection hole or covers the bottom surface and side surface of the connection hole, and then forms (111) on the first titanium nitride film. A titanium film effective for forming the second titanium nitride film oriented in the direction is formed, and then a part of the titanium film is nitrided (111).
A method of manufacturing a semiconductor device, comprising forming a second titanium nitride film oriented in the above manner, and laminating aluminum or its alloy film constituting the upper wiring layer on the second titanium nitride film.