JPH1167902A - Semiconductor integrated circuit device and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor integrated circuit device, with which a wiring pattern, provided with a plug consisting of tungsten film, can be patternized in a highly precise manner, and to provide a manufacturing method of the device. SOLUTION: A thin barrier metal film (the first barrier metal film) 10 is formed through-holes 9, and a thick barrier metal film (the second barrier film) 10a, which is thickner than the barrier metal film 10, is formed on an insulating film 8. After the deposition of a tungsten film of a semiconductor substrate 1, the tungsten film on the insulating film 8 is removed using an etch-back method, the surface of a part of the tungsten film embedded in the through-hole and the surface of the insulating film are formed into equally flat surface, and a plug 11a, consisting of the tungsten film embedded in the through-hole 9, is formed. After the removal of the barrier metal film 10a on the insulating film 8, a wiring layer is formed on the semiconductor substrate 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor integrated circuit device and a method of manufacturing the same, and more particularly, to a semiconductor integrated circuit device capable of patterning a wiring layer having a plug made of a tungsten film with high precision. The present invention relates to an effective semiconductor integrated circuit device and a method for manufacturing the same.

[0002]

2. Description of the Related Art The present inventors have studied a method of manufacturing a semiconductor integrated circuit device. The following is a technique studied by the present inventors, and the outline is as follows.

That is, in a method of manufacturing a semiconductor integrated circuit device, for example, a MOSFET (Metal Oxide Semico
nductor Field Effect Transistor) is formed on a semiconductor substrate, an interlayer insulating film is formed, a through hole is formed in the interlayer insulating film, and a plug made of a tungsten film is buried in the through hole, and then electrically connected to the plug. Wiring layer is formed.

In this case, a plug formed of a tungsten film is formed by embedding a tungsten film in a through hole using a thin titanium-based film (such as a titanium film or a titanium nitride film) as a barrier metal film and then embedding the through hole in the through hole. The tungsten film other than the tungsten film is removed by an etch-back method using dry etching.

[0005] Incidentally, as a document describing a technology for forming a wiring layer in a semiconductor integrated circuit device, for example, “Ninety-Sixth Latest Semiconductor Process Technology” published on November 2, 1989 by Press Journal, p. p273
Some are described in

[0006]

However, when the above-mentioned plug made of tungsten film is formed, a tungsten film other than the tungsten film buried in the through hole is removed by an etch-back method using dry etching. In this case, over-etching must be performed due to etching variation during dry etching, and thus a problem arises in that a recess (dent) is generated on the surface of the tungsten film as a plug, and the recess amount increases.

For this reason, when an aluminum alloy layer or the like as a wiring layer is deposited by sputtering on a region including a plug made of a tungsten film having a recess with a large recess amount, the upper portion of the plug is formed. Since a large recess is also formed on the surface of the wiring layer, a pattern failure of the photoresist film when forming the pattern of the wiring layer occurs, and a decrease in a margin when forming the pattern of the photoresist film. Occurs.

As a result, there is a problem that a pattern defect of the wiring layer and a decrease in margin when forming the pattern of the wiring layer occur.

It is an object of the present invention to provide a semiconductor integrated circuit device capable of patterning a wiring layer having a plug made of a tungsten film with high accuracy and a method of manufacturing the same.

The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0011]

SUMMARY OF THE INVENTION Among the inventions disclosed in the present application, the outline of a representative one will be briefly described.
It is as follows.

That is, the semiconductor integrated circuit device of the present invention has a plug made of a tungsten film embedded in a through hole formed in a selective region of an insulating film, and a recess is formed on the surface of the plug. A part of the surface of the plug and the surface of the insulating film are on the same plane.

According to the method of manufacturing a semiconductor integrated circuit device of the present invention, an insulating film is formed on a substrate such as a semiconductor substrate on which a semiconductor element is formed, and then a through hole is formed in a selective region of the insulating film. Forming a thin first barrier metal film in the through hole, and forming a thick second barrier metal film having a thickness larger than the first barrier metal film on the insulating film. After the tungsten film is deposited on the substrate, the tungsten film on the insulating film is removed using an etch-back method, and the part of the surface of the tungsten film embedded in the through hole is insulated. Forming a plug made of a tungsten film buried in the through-hole with the surface of the film being on the same plane, and forming a wiring layer on the substrate after removing the second barrier metal film; And a step.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings. In all the drawings for describing the embodiments, components having the same function are denoted by the same reference numerals, and redundant description will be omitted.

FIGS. 1 to 10 are schematic sectional views showing steps of manufacturing a semiconductor integrated circuit device according to an embodiment of the present invention. The semiconductor integrated circuit device and the method of manufacturing the same according to the present embodiment will be specifically described with reference to FIG.

First, as shown in FIG. 1, a silicon oxide film is formed on a device isolation region, which is a selective region on the surface of a semiconductor substrate (substrate) 1 made of, for example, p-type silicon single crystal by using thermal oxidation. A field insulating film 2 is formed. Next, a gate insulating film 3 made of, for example, a silicon oxide film is formed on the semiconductor substrate 1.
After forming a conductive polycrystalline silicon film thereon, an insulating film 5 made of, for example, a silicon oxide film is formed, and then the polycrystalline silicon film is patterned by using a photolithography technique and a selective etching technique. To form a gate electrode 4 and a patterned gate insulating film 3.

Thereafter, a sidewall spacer 6 made of, for example, a silicon oxide film is formed on the side wall of the gate electrode 4. Thereafter, an n-type impurity such as phosphorus is ion-implanted into the semiconductor substrate 1 to form an n-type semiconductor region 7 serving as a source and a drain.

In this case, the gate electrode 4 on the field insulating film 2 is used as a wiring layer.
In the above-described manufacturing process of the semiconductor integrated circuit device, an n-channel MOSFET is formed as a semiconductor element on the semiconductor substrate 1.
P-channel MOSFET other than SFET, CMOSFE
An embodiment in which various semiconductor elements such as T, a bipolar transistor, and a capacitor are formed can be employed.

Next, after an insulating film 8 is formed on the semiconductor substrate 1, a through hole (connection hole) 9 as a contact hole is formed in the insulating film 8 (FIG. 2).

In this case, the insulating film 8 is formed by depositing, for example, a silicon oxide film using a CVD (Chemical Vapor Deposition) method. After that, the surface of the insulating film 8 is planarized by using an etch-back method to form the insulating film 8 having a flat surface. Thereafter, through holes 9 are formed in insulating film 8 by using a photolithography technique and a selective etching technique.
To form

Next, a thin barrier metal film (first barrier metal film) 10 is formed in the through hole 9 by using a sputtering method or a CVD method, and a thick barrier metal film is formed on the insulating film 8. (Second barrier metal film) 1
0a is formed. Thereafter, a thick tungsten film 11 is deposited using a CVD method (FIG. 3).

In this case, the barrier metal film 10 and the barrier metal film 10a use a titanium-based film such as a titanium film or a titanium nitride film. Further, after forming a barrier metal film 10 of, for example, 500 Å on the semiconductor substrate 1, a barrier metal film is deposited again on the insulating film 8, and, for example, 1500 Å (of a thin film) is formed on the insulating film 8. The barrier metal film 10a (thick film which is three times the thickness of the barrier metal film 10) is formed.

Thereafter, the tungsten film 11 on the insulating film 8 is removed by an etch-back method using dry etching to form a plug 11a made of the tungsten film 11 embedded in the through hole 9 (FIG. 4).

In this case, as a result of the study of the present inventor, although a recess (recess) having a recess amount of, for example, about 200 angstroms is formed on the surface of the plug 11a, a part of the surface of the plug 11a is insulated. In order to make the surface of the film 8 the same plane as that of the barrier metal film 10, the thickness of the barrier metal film 10a is made larger than the thickness of the barrier metal film 10;
The thickness of the barrier metal film 10a is at least three times the thickness of the barrier metal film 10.

As a result, unnecessary tungsten film 1 other than tungsten film 11 buried in through hole 9
1 can be prevented from being etched beyond the thickness of the thick barrier metal film 10a even if over-etching is performed when the etch-back method is performed using the etch-back method, and the recess formed on the surface of the plug 11a. Can be reduced from about 500 Å to about 200 Å. Further, since the thick barrier metal film 10 a is formed, over-etching can be adjusted, so that a part of the surface of the plug 11 a made of the tungsten film 11 embedded in the through hole 9 is insulated. The surface of the film 8 can be flush with the surface.

Next, the barrier metal film 1 on the insulating film 8 is etched using an etch-back method using dry etching.
The operation of removing Oa is performed (FIG. 5).

Next, a barrier metal film 12, an aluminum alloy layer 13, and a barrier metal film 14 are formed on the semiconductor substrate 1.
Is formed (FIG. 6).

In this case, the barrier metal film 12 and the barrier metal film 14 use a titanium-based film such as a titanium film or a titanium nitride film. The aluminum alloy layer 13 is made of silicon (Si), copper (Cu), magnesium (Mg), germanium (Ge), zinc (Zn),
An aluminum alloy layer containing a small amount of at least one material of gallium (Ga) is used.

After forming a barrier metal film 12 of, for example, 200 angstroms on the semiconductor substrate 1 by using a sputtering method, an aluminum alloy layer 13 of, for example, 5000 angstroms is formed.
For example, the barrier metal film 14 of 750 angstroms is formed.

By the above-described manufacturing process, the through hole 9 is formed.
A part of the surface of the plug 11a made of the tungsten film 11 embedded in the insulating film 8 and the surface of the insulating film 8 are flush with each other, and the barrier metal film 10a on the insulating film 8 is removed. When forming the wiring layer 15, the surface of the wiring layer 15 can be made flat.

Thereafter, a photoresist film 16 is applied to the surface of the wiring layer 15 and then a patterned photoresist film 16 for forming a wiring pattern is formed by using a photolithography technique (FIG. 7). .

In this case, the wiring layer 15 having a flat surface
Of the photoresist film 16 having a flat surface can be coated on the surface of the photoresist film 16.
The photoresist film 1 is patterned with high precision corresponding to the pattern according to the design specification.
6 can be formed. In addition, it is possible to prevent the occurrence of a pattern failure of the photoresist film 16 when forming the wiring layer pattern, and to prevent a decrease in margin when forming the pattern of the photoresist film 16.

Next, using the photoresist film 16 as an etching mask, the patterned wiring layer 15 is formed by a selective etching technique such as dry etching.
Is formed (FIG. 8).

In this case, the wiring layer 15 having a flat surface
In addition, since the patterned wiring layer 15 is formed by using the photoresist film 16 that is patterned with high precision as an etching mask, the patterning is performed with high precision corresponding to the design specification. The wiring layer 15 can be formed. Further, it is possible to prevent a pattern defect of the wiring layer 15 and a decrease in a margin when forming a pattern of the wiring layer 15 from occurring.

Thereafter, the unnecessary photoresist film 1
After removing 6, an insulating film 17 as an interlayer insulating film is formed on the semiconductor substrate 1, a through hole 18 is formed in the insulating film 17, and the barrier metal film 1 is formed in the through hole 18.
9 and a plug 20 made of a tungsten film are formed (FIG. 9). In this case, the manufacturing process is performed using the same manufacturing process as the manufacturing process of the plug 11a from the manufacturing process of the insulating film 8 described above.

Next, a barrier metal film 21, an aluminum alloy layer 22, and a barrier metal film 23 are formed on the semiconductor substrate 1.
Is formed (FIG. 10). In this case, the manufacturing process is performed using the same manufacturing process as the manufacturing process of the wiring layer (first wiring layer) 15 described above.

Thereafter, according to the design specifications, the above-described manufacturing steps (the insulating film 17 as an interlayer insulating film, the through-hole 1
8, the manufacturing process of the semiconductor integrated circuit device of the present embodiment is completed by repeatedly performing the steps of manufacturing the plug 20, the wiring layer 24 as the second wiring layer, and forming a multilayer wiring layer.

According to the method of manufacturing a semiconductor integrated circuit device of the present embodiment described above, a recess having a recess amount of, for example, about 200 angstroms is formed on the surface of the plug 11a. In order to make a part of the surface of the insulating film 8 and the surface of the insulating film 8 the same plane, the barrier metal film 1
The thickness of the barrier metal film 10a is set to be three times or more the thickness of the barrier metal film 10 in particular.

As a result, unnecessary tungsten film 1 other than tungsten film 11 buried in through hole 9
1 can be prevented from being etched beyond the thickness of the thick barrier metal film 10a even if over-etching is performed when the etch-back method is performed using the etch-back method, and the recess formed on the surface of the plug 11a. Can be reduced from about 500 Å to about 200 Å. Further, since the thick barrier metal film 10 a is formed, over-etching can be adjusted, so that a part of the surface of the plug 11 a made of the tungsten film 11 embedded in the through hole 9 is insulated. The surface of the film 8 can be flush with the surface. Therefore, a semiconductor integrated circuit device having the plug 11a made of the tungsten film 11 having a highly accurate pattern can be obtained.

According to the method of manufacturing a semiconductor integrated circuit device of the present embodiment described above, the barrier metal film 10 a on the insulating film 8 is removed, and the plug 11 a made of the tungsten film 11 embedded in the through hole 9 is formed. In the state where a part of the surface and the surface of the insulating film 8 are on the same plane, the wiring layer 15 is deposited thereon,
The wiring layer 15 having a flat surface can be formed.

After a photoresist film 16 is applied to the surface of the wiring layer 15, when the patterned photoresist film 16 for forming a wiring pattern is formed using photolithography technology, the photoresist film 16 is flattened. Since the photoresist film 16 can be coated on the surface of the wiring layer 15 having a smooth surface, the photoresist film 16 can have a flat surface, so that it can be formed with high precision corresponding to a pattern according to design specifications. A patterned photoresist film 16 can be formed. In addition, it is possible to prevent the occurrence of a pattern failure of the photoresist film 16 when forming the wiring layer pattern, and to prevent a decrease in margin when forming the pattern of the photoresist film 16.

Therefore, when the patterned wiring layer 15 is formed by using the photoresist film 16 as an etching mask and using a selective etching technique such as dry etching, the wiring layer 15 having a flat surface is formed.
In addition, since the patterned wiring layer 15 is formed by using the photoresist film 16 that is patterned with high precision as an etching mask, the patterning is performed with high precision corresponding to the design specification. The wiring layer 15 can be formed. Further, it is possible to prevent a pattern defect of the wiring layer 15 and a decrease in a margin when forming a pattern of the wiring layer 15 from occurring.

According to the method of manufacturing a semiconductor integrated circuit device of the present embodiment, the etching is performed when the plug 11a made of the tungsten film 11 is formed by using the etch-back method. Since a conventional manufacturing apparatus that performs the method can be used, a simple manufacturing process can be performed, and the etch-back method is used.
(Chemical Mechanical Polishing), the throughput can be improved.

Although the invention made by the inventor has been specifically described based on the embodiments of the present invention, the present invention is not limited to the above embodiments, and various modifications may be made without departing from the gist of the invention. Needless to say, it can be changed.

For example, the present invention relates to a CMOS Logic.
For example, the method is applied to a method of manufacturing a semiconductor integrated circuit device having a multilayer wiring structure having a dot pattern of about 0.4 μm × 0.4 μm on a through hole. Also, a wiring layer having a highly accurate pattern can be formed.

Further, according to the present invention, a semiconductor substrate on which a semiconductor element is formed can be changed to various substrates such as an SOI (Silicon on Insulator) substrate. In addition to the MOSFET, a semiconductor element in which various semiconductor elements such as a CMOSFET and a bipolar transistor are combined can be applied.

The present invention also relates to a MOSFET, a CMOS,
Logic or DRA with FET etc. as components
M (Dynamic Random Access Memory), SRAM (Stat
The present invention can be applied to various semiconductor integrated circuit devices having a memory system such as an IC (Random Access Memory) and a method of manufacturing the same.

[0048]

Advantageous effects obtained by typical ones of the inventions disclosed in the present application will be briefly described.
It is as follows.

(1). According to the method for manufacturing a semiconductor integrated circuit device of the present invention, when an unnecessary tungsten film other than the tungsten film embedded in the through hole is removed by using the etch-back method, even if overetching is performed, Film barrier metal film (second barrier metal film)
Can be prevented from being etched beyond the thickness of the plug, and the recess amount of the recess formed on the surface of the plug can be reduced to the conventional value of 5.
It can be reduced from about 00 angstroms to about 200 angstroms. In addition, since the thick barrier metal film is formed, over-etching can be adjusted, so that part of the surface of the plug made of the tungsten film embedded in the through hole and the surface of the insulating film can be adjusted. Can be the same plane.
Therefore, a semiconductor integrated circuit device having a plug made of a tungsten film having a highly accurate pattern can be obtained.

(2). According to the method for manufacturing a semiconductor integrated circuit device of the present invention, the barrier metal film (second barrier metal film) on the insulating film is removed, and the surface of the plug made of the tungsten film embedded in the through hole is removed. The wiring layer having a flat surface can be formed by depositing the wiring layer thereon while the portion and the surface of the insulating film are on the same plane.

After a photoresist film is applied to the surface of the wiring layer, a flat surface is formed when a patterned photoresist film for forming a wiring pattern is formed by using a photolithography technique. A photoresist film having a flat surface can be formed by applying a photoresist film to the surface of a wiring layer having the same, so that a photoresist patterned with high precision corresponding to a pattern according to design specifications A film can be formed. Further, it is possible to prevent the occurrence of a pattern defect of the photoresist film when forming the wiring layer pattern, and to prevent the margin from being reduced when forming the pattern of the photoresist film.

Therefore, when a patterned wiring layer is formed by using a photoresist film as an etching mask and using a selective etching technique such as dry etching, the wiring layer having a flat surface can be formed. By using a highly patterned photoresist film as an etching mask to form a patterned wiring layer, a highly patterned wiring layer corresponding to the design specifications is formed. be able to. Further, it is possible to prevent the occurrence of a pattern defect in the wiring layer and a decrease in margin when forming the wiring layer pattern.

(3). According to the method of manufacturing a semiconductor integrated circuit device of the present invention, a conventional manufacturing apparatus which performs an etch-back method by performing etching when a plug made of a tungsten film is formed by using an etch-back method. Can be used, a simple manufacturing process can be realized, and the etch-back method is used, so that the throughput can be improved as compared with the CMP method.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a manufacturing process of a semiconductor integrated circuit device according to an embodiment of the present invention.

FIG. 2 is a schematic sectional view showing a manufacturing process of the semiconductor integrated circuit device according to one embodiment of the present invention;

FIG. 3 is a schematic sectional view showing a manufacturing process of the semiconductor integrated circuit device according to one embodiment of the present invention;

FIG. 4 is a schematic cross-sectional view showing a manufacturing step of the semiconductor integrated circuit device according to one embodiment of the present invention;

FIG. 5 is a schematic cross-sectional view showing a manufacturing step of the semiconductor integrated circuit device according to one embodiment of the present invention;

FIG. 6 is a schematic cross-sectional view showing a manufacturing step of the semiconductor integrated circuit device according to one embodiment of the present invention;

FIG. 7 is a schematic cross-sectional view showing a manufacturing step of the semiconductor integrated circuit device according to one embodiment of the present invention;

FIG. 8 is a schematic cross-sectional view showing a manufacturing step of the semiconductor integrated circuit device according to one embodiment of the present invention;

FIG. 9 is a schematic cross-sectional view showing a manufacturing step of the semiconductor integrated circuit device according to one embodiment of the present invention;

FIG. 10 is a schematic cross-sectional view showing a manufacturing step of the semiconductor integrated circuit device according to one embodiment of the present invention;

[Explanation of symbols]

 Reference Signs List 1 semiconductor substrate (substrate) 2 field insulating film 3 gate insulating film 4 gate electrode 5 insulating film 6 sidewall spacer 7 semiconductor region 8 insulating film 9 through hole 10 barrier metal film (first barrier metal film) 10a barrier metal film ( 2nd barrier metal film) 11 tungsten film 11a plug 12 barrier metal film 13 aluminum alloy layer 14 barrier metal film 15 wiring layer 16 photoresist film 17 insulating film 18 through hole 19 barrier metal film 20 plug 21 barrier metal film 22 aluminum alloy Layer 23 Barrier metal film 24 Wiring layer

Claims (10)

[Claims] A plug formed of a tungsten film buried in a through hole formed in a selective region of the insulating film, wherein a recess is formed on a surface of the plug; A semiconductor integrated circuit device, wherein a part and a surface of the insulating film are on the same plane. 2. The semiconductor integrated circuit device according to claim 1, wherein a barrier metal film is formed between said plug and said through hole. 3. The semiconductor integrated circuit device according to claim 1, wherein a wiring layer having a three-layer structure including a barrier metal film, an aluminum alloy layer, and a barrier metal film is formed on the plug. A semiconductor integrated circuit device. 4. The semiconductor integrated circuit device according to claim 2, wherein said barrier metal film is a titanium-based film. 5. A step of forming an insulating film on a substrate on which a semiconductor element is formed, and then forming a through hole in a selective region of the insulating film; Forming a barrier metal film, forming a thick second barrier metal film having a thickness larger than the first barrier metal film on the insulating film, and forming a tungsten film on the substrate. Removing the tungsten film on the insulating film using an etch-back method, and forming a plug made of the tungsten film embedded in the through hole; Forming a wiring layer on the substrate after removing the metal film. 6. The method for manufacturing a semiconductor integrated circuit device according to claim 5, wherein said second barrier metal film has a thickness of:
A method for manufacturing a semiconductor integrated circuit device, wherein the thickness is three times or more the thickness of the first barrier metal film. 7. The method for manufacturing a semiconductor integrated circuit device according to claim 6, wherein said second barrier metal film has a thickness of:
A method for manufacturing a semiconductor integrated circuit device, which is at least 1500 angstroms. 8. The method for manufacturing a semiconductor integrated circuit device according to claim 5, wherein said wiring layer comprises:
A method for manufacturing a semiconductor integrated circuit device, comprising: a wiring layer having a three-layer structure including a barrier metal film, an aluminum alloy layer, and a barrier metal film. 9. The method for manufacturing a semiconductor integrated circuit device according to claim 5, wherein said barrier metal film is a titanium-based film. Production method. 10. The method for manufacturing a semiconductor integrated circuit device according to claim 5, wherein a part of a surface of said tungsten film embedded in said through hole and said insulating film. Characterized by being substantially flush with the surface of the semiconductor integrated circuit device.