JPH113871A - Semiconductor device and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress melting and flowing of an electric conductive substance and to make a proper junctioning condition by a size in the horizontal direction of junctioning upper part of an alkaline proof electric conductive film being more than a size corresponding to a deviation of overlapping which is generated at the time of forming a border-less wiring and being a specific value of the maximum size in the horizontal direction of the junctioning part. SOLUTION: A contact 8 is constituted of a titanium nitride film 8a of alkaline proof which is made by film forming contacting with an interlayer insulating film 7 and an impurity region 3, and a tungsten film 8b which is buried in a recess which is comprised of the titanium nitride film 8a. Here the contact 8 is so formed as the titanium nitride film 8a having a thickness more than 1000 and less than 1500 Å to surround the outer peripheral of the contact 8. The film thickness in the horizontal direction has a longer size corresponding to an overlapping deviation of the contact 8 and a metal wiring 9 which is a boarder-less wiring, and is made to be less film thickness than a half of the contact 8 in the horizontal direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a semiconductor device, and more particularly to a structure of a contact of the semiconductor device or a via hole for electrically connecting an upper wiring and a lower wiring, and a manufacturing method thereof.

[0002]

2. Description of the Related Art FIG. 30 is a sectional view showing the structure of a contact formed by a conventional technique. In this figure, reference numeral 101 denotes a semiconductor substrate. The region 101a has been formed. Further, an interlayer insulating film 102 is formed on one main surface of the semiconductor substrate 101, and the impurity region 101a is formed.
A contact 103 is buried from the surface to the bottom surface of the interlayer insulating film 102 so as to contact with the contact. Contact 1
Numeral 03 is formed in a cylindrical shape and includes a titanium nitride film 103a and a tungsten nitride film 103b.

[0003] A titanium silicide film 104 is formed between the contact 103 and the semiconductor substrate 101, and a titanium nitride film 103 a is formed on the cylindrical side wall which is the boundary with the interlayer insulating film 102 and on the titanium silicide film 104 which is the bottom surface thereof. The tungsten film 103 is covered on the surface of the titanium nitride film 103a so as to bury the opening of the interlayer insulating film 102.
b is filled. On the surface of the interlayer insulating film 102, a metal wiring 105 arranged in contact with the upper part of the contact 103 is formed.

[0004] As described above, the tungsten film 103b is made of a silicon oxide film having poor adhesion.
Instead of being formed in a state of being in direct contact with the substrate, the adhesion between them is improved by arranging them through the titanium nitride film 103a.

Next, a brief description will be given of a method of manufacturing the semiconductor device shown in FIG. First, as shown in FIG. 31A, a silicon oxide film having a thickness of 10,000 to 15000 ° is laminated as an interlayer insulating film 102 on the surface of the semiconductor substrate 101, and thereafter, the surface of the semiconductor substrate 101 is A contact hole 106 having an opening diameter of 4000 to 5000 ° is formed over one main surface. After that, impurity implantation is performed to form an impurity region 101a on one main surface of the semiconductor substrate 101. This impurity region 101a is an interlayer insulating film 102
It is also possible to form the film before forming the film. This opening diameter 4
Contact holes 106 having a multilayer structure of 000-5000 ° are generally used for semiconductor devices of half-micron devices.

Next, as shown in FIG. 31B, a titanium film is formed on a surface of a substrate to be processed (hereinafter, a semiconductor device in the manufacturing process is referred to as a substrate to be processed) including a side wall and a bottom surface of the contact hole 106. 107 are stacked by a sputtering method so that the thickness on the flat surface of the interlayer insulating film 102 becomes 200 °. Thereafter, a titanium nitride film 108 is laminated on the surface of the titanium film 107 by a sputtering method so that the thickness on the flat surface of the interlayer insulating film 102 becomes 1000 °.

At this time, 30% of the film thickness on the flat surface of interlayer insulating film 102 is formed on the side wall of contact hole 106.
A titanium film 107 and a titanium nitride film 108 having a film thickness of the order of magnitude are formed. In this case, the total thickness of the titanium film 107 and the titanium nitride film 108 on the side wall of the contact hole 106 is about 360 °.

Thereafter, as shown in FIG. 31C, heat treatment (for example, at 800 ° C. for 30 seconds) is applied in a nitriding atmosphere. By this heat treatment, the titanium film 107 and the semiconductor substrate 1
01 reacts, a titanium silicide film 104 is formed on the bottom of the contact hole 106, and the titanium film 107 formed in other regions is nitrided to become a titanium nitride film 103a. The thickness of the side wall of the contact hole 106 of the titanium nitride film 103a is substantially equal to the total thickness of the titanium film 107 and the titanium nitride film 108, and
It is about the size of Å.

Next, as shown in FIG. 31D, a tungsten film 109 is laminated on the entire surface of the substrate to be processed by a blanket CVD method, and the inside of the contact hole 106 is buried with a conductive material. Furthermore, as shown in FIG. 31E, the entire surface of the tungsten film 109 is etched back to expose the surface of the interlayer insulating film 102, and only the tungsten film 103b is left in the contact hole 106. The tungsten film 103b and the titanium nitride film 103
a can form the contact 103.

Next, as shown in FIG. 31 (f), a metal film 110 for wiring made of an aluminum alloy is laminated to a thickness of about 5000 °. Thereafter, as shown in FIG. 31 (g), a resist pattern 111 having a shape corresponding to the metal wiring 105 is formed on the metal film 110 through a photolithography process. The resist pattern 111 has a shape of the metal wiring 105, that is, a pad portion of 1.0 μm square on the contact 103, and has a wiring width of about 0.5 μm.

Next, as shown in FIG. 1H, the metal film 110 is etched using the resist pattern 111 as an etching mask to obtain a metal wiring 105. After that, by removing the resist pattern 111, the semiconductor device shown in FIG. 30 can be obtained.

In the above description, an example in which the metal wiring 105 and the impurity region 101a are connected via the contact 103 has been described. However, the same structure can be applied to the case where the lower wiring and the upper wiring are connected via via holes. It becomes possible by applying.

Further, the upper wiring formed in contact with the upper portion of the contact or via hole has a multilayer structure in order to enhance the adhesion to the interlayer insulating film, and has a two-layer structure of titanium and titanium nitride so as to be in contact with the interlayer insulating film. In some cases,

[0014] Another prior art, Japanese Patent Laid-Open No. 5-1 is disclosed.
Japanese Patent No. 14578 discloses a contact formed for electrical connection between an impurity region formed on one main surface of a semiconductor substrate and an upper wiring formed on an upper layer via an interlayer insulating film. According to Japanese Patent Application Laid-Open No. 5-114578, a contact structure is such that a titanium film, a titanium nitride film, and a silicon film are sequentially stacked in a contact hole (including a side wall and a bottom surface) formed in an interlayer insulating film. Further, it has a structure in which a tungsten film is embedded.

The feature of this contact is that its structure includes a silicon film, and even when a crack is formed in the adhesion layer made of a titanium film and a titanium nitride film, the reaction gas during the formation of tungsten is not affected. The structure is such that the silicon film on the surface of the adhesion layer is sacrificed so as not to damage the semiconductor substrate through the crack.

[0016]

The positional relationship between the contact 103 and the metal wiring 105 in the semiconductor device formed as shown in FIG. 30 will be described below. In a semiconductor device of a half-micron device, FIG.
As shown in FIG. 2A, the metal wiring 105 connected to the contact 103 has a pad portion whose wiring width is partially increased, and a cover margin (x = 2500 °) is secured. In this case, as shown in FIG. 32 (b), even when the displacement of the superposition occurs and the contact 103 and the metal wiring 105 are not arranged as designed, the cover margin x is sufficiently secured. There was no deterioration of the connection between them, such as a part of the wire protruding from the metal wiring 105.

However, sub-quarter micron devices have been applied due to the miniaturization accompanying the high integration of semiconductor devices.
It is no longer possible to form a cover margin at the connection between the contact 103 and the metal wiring 105, and FIG.
As shown in FIG. 5, a borderless wiring 105a without a cover margin is formed. The width of the borderless wiring 105a is equal to that of the contact 103aa.
Is 3000 mm, while 3000 to 4000
配線 is the wiring width.

For example, when a borderless wiring 105a having a wiring width of 4000 ° is used, as shown in FIG.
If the displacement is larger, the contact 103
The connection area between the contact 103aa and the borderless wiring 105a is reduced, and the upper surface of the contact 103aa is partially exposed. FIG. 34 (a) shows a cross-sectional structure in the case where the overlapping shift occurs. In this figure, reference numeral 111a is a resist pattern.

Further, since the upper portion of the contact 103aa and the borderless wiring 105a are not completely connected, the resist pattern 111a formed for patterning the borderless wiring 105a is formed.
When an optimal strong alkaline etching solution is used for removing the contact, as shown in FIG.
3aa, the tungsten film 103b is melted,
The void is formed, and the connection between the contact 103 and the borderless wiring 105a is made by the titanium nitride film 10.
This is a state in which the connection is made only by 3a, and a problem occurs in the electrical connection. In addition, the misalignment has also been caused by, for example, CD loss, which is a phenomenon in which wiring is formed smaller than a dimension to be actually formed. Note that the misalignment of the wiring and the contact is less than 10 in a sub-quarter micron device.
It can be about 00mm or smaller,
We know from the accuracy of current photoengraving.

In the above example, the resist pattern 11
Although an example in which a strong alkaline etching solution is used to remove 1a has been described, the resist pattern 111a was first removed by performing oxygen plasma etching, and then occurred during anisotropic etching for forming the borderless wiring 105a. Even in the case where a method of removing a polymer as a foreign substance by using a strong alkaline etching solution is employed, similarly, the disappearance of tungsten exposed to the strong alkaline etching solution becomes a problem.

In another example, as shown in FIG. 35, in order to improve the adhesion between the interlayer insulating film 110 and the contact or via hole, the borderless wiring 105a is formed of TiN /
When a titanium film is formed in the lowermost layer of the borderless wiring 105a, the borderless wiring 1 has a multi-layer structure including a Ti adhesion layer 105aa and a metal film 105bb.
In some cases, a resist pattern used as an etching mask in the patterning of the pattern 05a is removed by oxygen plasma ashing, and a polymer generated during patterning of the borderless wiring 105a is removed using a strong alkaline etching solution.

In this case, the titanium film forming the borderless wiring 105a is simultaneously etched at a rate of 130 ° / min, and the etching of the titanium film is performed by the tungsten 103b buried in the contact or via hole.
, The tungsten 103b is also etched by the strong alkaline etchant, and the electrical connection at this connection becomes poor. If the tungsten film 103b is exposed during the removal of the resist pattern due to the displacement between the borderless wiring 105a and the contact 103aa, it goes without saying that the elution of the tungsten film 103b by the strong alkaline etchant is more remarkable.

According to the present invention, a strong alkaline etching solution is used even when the contact or via hole and the upper wiring formed on the contact or via hole are misaligned, or when there is misalignment due to CD loss. It is an object of the present invention to provide a semiconductor device capable of suppressing the elution of a conductive substance forming a contact or a via hole during a process and achieving a good connection state, and a method for manufacturing the same.

[0024]

According to a first aspect of the present invention, there is provided a semiconductor device, a semiconductor substrate, a conductive region formed on a surface or an upper portion of the semiconductor substrate, and an interlayer insulating film laminated on at least the conductive region. A connection portion made of a conductive substance formed from the upper surface of the conductive region to the surface of the conductive region,
A borderless wiring formed on the surface of the interlayer insulating film in contact with the connection portion, wherein the connection portion includes an alkali-resistant conductive film, and at least the connection of the alkali-resistant conductive film surrounding the outer periphery of the connection portion; The film thickness in the horizontal direction in the upper part is a value equal to or larger than the dimension corresponding to the misalignment of the connection portion and the borderless wiring,
The connection portion is formed so as to have a film thickness smaller than １ ／ of the maximum horizontal dimension.

According to a second aspect of the present invention, in addition to the configuration of the first aspect, the horizontal dimension of the alkali-resistant conductive film in the upper portion of the connection portion is not less than 1000 ° and less than 1500 °. Of the size.

Further, in the semiconductor device according to claim 3 of the present invention, in addition to the structure of the semiconductor device according to claim 1 or 2, the alkali-resistant conductive film is formed of a titanium nitride film or a titanium nitride film and a titanium tungsten film. It has a multilayer structure.

According to a fourth aspect of the present invention, there is provided a semiconductor device, comprising: a semiconductor substrate, a conductive region formed on or above the semiconductor substrate, and at least an upper surface of an interlayer insulating film laminated on the conductive region. A connection portion made of a conductive material formed over the surface of the conductive region, in contact with the connection portion, including an upper wiring formed on the surface of the interlayer insulating film, the connection portion includes an alkali-resistant conductive film,
The alkali-resistant conductive film is a nitride conductive film in which the upper surface of the connection portion is nitrided or a conductive titanium compound in which the upper surface of the connection portion is combined with titanium. The connection is performed through the nitride conductive film or the conductive titanium compound. And the upper layer wiring are electrically connected.

Further, according to a fifth aspect of the present invention, there is provided a semiconductor device comprising: a semiconductor substrate, a conductive region formed on a surface or an upper portion of the semiconductor substrate, and at least an upper surface of an interlayer insulating film laminated on the conductive region. A connection portion made of a conductive material formed over the surface of the conductive region, in contact with the connection portion, including an upper wiring formed on the surface of the interlayer insulating film, the connection portion includes an alkali-resistant conductive film, The alkali-resistant conductive film is selectively formed in a region on the upper surface of the connection portion that does not overlap with the upper wiring.

Further, in the semiconductor device according to a sixth aspect of the present invention, in addition to the structure of the semiconductor device according to the fifth aspect, the upper wiring has a multilayer structure, has an adhesion layer at the lowermost layer, and has at least the adhesion layer. An alkali-resistant nitride film is formed on the cross section.

According to a seventh aspect of the present invention, there is provided a semiconductor device comprising: a semiconductor substrate, a conductive region formed on a surface or an upper portion of the semiconductor substrate, and at least an upper surface of an interlayer insulating film laminated on the conductive region. A connection portion made of a conductive material formed over the surface of the conductive region, an upper-layer wiring in contact with the connection portion, and formed on the surface of the interlayer insulating film;
At least a conductive film sandwiched between the bottom surface of the upper wiring and the surface of the interlayer insulating film and adhered to the side wall of the connection portion is provided. In this case, an alkaline nitride film is formed.

Further, in the semiconductor device according to an eighth aspect of the present invention, in addition to the structure of the semiconductor device according to the seventh aspect, the conductive film has a laminated structure of at least an alkali-resistant conductive film and an alkali-soluble conductive film. The film is formed by nitriding a cross section of the alkali-soluble conductive film.

According to a ninth aspect of the present invention, there is provided a semiconductor device comprising: a semiconductor substrate, a conductive region formed on a surface or an upper portion of the semiconductor substrate, and at least an upper surface of an interlayer insulating film laminated on the conductive region. A connection portion made of a conductive material formed over the surface of the conductive region, including an upper layer wiring formed on the surface of the interlayer insulating film in contact with the connection portion, wherein the upper layer wiring is formed on a metal film and a bottom surface of the metal film. A multilayer structure including an alkali-resistant conductive film to be attached, wherein the alkali-resistant conductive film is formed under the bottom surface of the metal film and under the bottom surface of a sidewall attached to a side cross section of the metal film.

According to a tenth aspect of the present invention, in addition to the structure of any one of the first, second, fourth to seventh and ninth aspects, the connecting portion is formed in a semiconductor substrate. The contact hole connects the doped impurity region and the first metal wiring, or the via hole connects the first metal wiring and the second metal wiring.

According to a eleventh aspect of the present invention, in addition to the configuration of the semiconductor device according to any one of the fourth to ninth aspects, the alkali-resistant conductive film includes a titanium nitride film, a titanium tungsten film, and a tungsten nitride film. One of the films is used, and a titanium nitride film is used as the alkali-resistant nitride film.

According to a twelfth aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising the steps of: laminating an interlayer insulating film on a surface of a semiconductor substrate or a surface of a conductive region formed on the semiconductor substrate;
Forming an opening reaching the surface of the conductive region from the surface of the interlayer insulating film, laminating an alkali-resistant conductive film on the surface of the interlayer insulating film including at least the side wall of the opening, Stacking a tungsten film on the surface of the substrate, burying the opening, performing etch back to the surface of the interlayer insulating film, and forming a connection portion including the alkali-resistant conductive film and the tungsten film buried in the opening. A step of forming a borderless wiring using a resist pattern in contact with the connection portion on the interlayer insulating film, using a strong alkaline etchant to remove foreign matter generated when the resist pattern or the resist pattern is removed. Removing the alkali-resistant conductive film in the horizontal direction on the extending surface of the interlayer insulating film surface Not less than the magnitude of the deviation of superposition with and the and the borderless interconnect the connecting section, in which a film thickness of less than half of the maximum diameter of the opening.

Further, according to a method of manufacturing a semiconductor device according to a thirteenth aspect of the present invention, in the method of manufacturing a semiconductor device of the eleventh aspect, the film thickness in the horizontal direction on the extending surface of the surface of the interlayer insulating film of the alkali-resistant conductive film. Is more than 1000Å150
The size should be less than 0 °.

According to a fourteenth aspect of the present invention, there is provided a method for manufacturing a semiconductor device, comprising the steps of: laminating an interlayer insulating film on a surface of a semiconductor substrate or a surface of a conductive region formed on the semiconductor substrate;
Forming an opening reaching the surface of the conductive region from the surface of the interlayer insulating film, laminating an adhesion layer on the surface of the interlayer insulating film including at least the side wall of the opening, and forming tungsten on the surface of the adhesion layer. Stacking a film and burying the opening; performing etch back to the surface of the interlayer insulating film to obtain a connection portion including the adhesion layer and the tungsten film buried in the opening; Making the upper surface of the portion an alkali-resistant conductive film, forming an upper layer wiring on the interlayer insulating film in contact with the connection portion using a resist pattern, removing foreign matter generated when the resist pattern or the resist pattern is removed. A step of removing using a strong alkaline etching solution, wherein the alkali-resistant conductive film is formed by nitriding or forming a titanium compound on the upper surface of the connection portion. It is intended to be formed at Rukoto.

Further, according to a method of manufacturing a semiconductor device according to a fifteenth aspect of the present invention, a step of laminating an interlayer insulating film on a surface of a semiconductor substrate or a surface of a conductive region formed on the semiconductor substrate, Forming an opening reaching the surface of the conductive region, laminating an adhesion layer on the surface of the interlayer insulating film including at least the side wall of the opening, laminating a tungsten film on the surface of the adhesion layer, Burying a portion, etching back to the surface of the interlayer insulating film to obtain a connection portion including the adhesion layer and the tungsten film buried in the opening, and forming the connection portion on the interlayer insulating film. Forming an upper wiring using a resist pattern in contact with the portion, and nitriding an exposed upper surface of the connection portion located in a region where the upper wiring and the connection portion do not overlap with each other Step includes a step of removing by using the resist pattern or the resist pattern foreign matter strongly alkaline etching solution generated during removal, and forms alkali-resistant conductive film by nitriding the upper surface of the connecting section.

According to a method of manufacturing a semiconductor device according to claim 16 of the present invention, in the method of manufacturing a semiconductor device of claim 14, the upper wiring is formed to have a multilayer structure including an adhesion layer and a metal film. When the adhesion layer is made of an alkali-soluble substance, in the step of nitriding the exposed upper surface of the connection portion located in a region where the upper wiring and the connection portion do not overlap, simultaneously nitriding the exposed portion of the adhesion layer It is.

Further, according to a method of manufacturing a semiconductor device according to a seventeenth aspect of the present invention, a step of laminating an interlayer insulating film on a surface of a semiconductor substrate or a surface of a conductive region formed on an upper portion thereof, Forming an opening reaching the surface of the conductive region, laminating an adhesion layer on the surface of the interlayer insulating film including at least the side wall of the opening, laminating a tungsten film on the surface of the adhesion layer, Etching back the tungsten film using the adhesion layer as an etching mask, obtaining a connection portion made of the adhesion layer and the tungsten film in the opening, laminating a metal film on the surface of the connection portion and the adhesion layer, Forming a resist pattern at a position on the metal film that overlaps with the connection portion; and forming the metal film using the resist pattern as an etching mask. A step of obtaining an upper layer wiring by sequentially and anisotropically etching the adhesion layer, a step of nitriding the exposed section of the connection portion and the upper layer wiring, and a strong alkaline etching solution for removing the resist pattern or foreign matter generated when the resist pattern is removed. And removing the exposed section of the connection portion and the upper wiring by nitriding the exposed section, thereby completely covering the exposed section with an alkali-resistant conductive film.

A method of manufacturing a semiconductor device according to claim 18 of the present invention comprises the steps of: laminating an interlayer insulating film on a surface of a semiconductor substrate or a surface of a conductive region formed on the semiconductor substrate;
Forming an opening reaching the surface of the conductive region from the surface of the interlayer insulating film, laminating a first adhesion layer on a surface of the interlayer insulating film including at least a side wall of the opening, A step of laminating a tungsten film on the surface of the adhesion layer and burying the opening, performing etch back to the surface of the interlayer insulating film, and removing the first adhesion layer and the tungsten film buried in the opening. A step of obtaining a connection portion including: a step of sequentially laminating a second adhesion layer, which is an alkali-resistant conductive film, and a metal film on the interlayer insulating film and in contact with the connection portion; and superimposing the metal film on the connection portion. Patterning into a shape of an upper wiring to be formed, forming a sidewall in a side cross section of the upper wiring, removing the other by leaving the sidewall and the second adhesion layer located below the upper wiring. It is intended to include that process.

According to a nineteenth aspect of the present invention, in the method of manufacturing a semiconductor device according to any one of the eleventh and thirteenth aspects, the connecting portion is formed in the semiconductor substrate. It is formed as a contact hole connecting the doped impurity region and the first metal wiring, or as a via hole connecting the first metal wiring and the second metal wiring.

[0043]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. Embodiment 1 of the present invention will be described. FIG. 1 shows a structure of a contact or via hole constituting an IC of a semiconductor device of the present invention and a wiring connected thereto.

In FIG. 1, reference numeral 1 denotes a semiconductor substrate, and 2 denotes an LOC formed in an inactive region on one main surface of the semiconductor substrate 1.
An OS (local oxidation of silicon) oxide film 3 is selectively formed in the active region on one main surface of the semiconductor substrate 1 and the MO
An impurity region 4 serving as a source / drain region of the S transistor is a gate oxide film laminated on a region serving as a channel sandwiched between impurity regions 3 on one main surface of the semiconductor substrate 1.
Is a MOS (metal oxide) formed on the gate insulating film 4
semiconductor) The gate electrode of the transistor, and the gate electrode 5 has a laminated structure of a polysilicon film 5a and a tungsten silicide film 5b. Further, a side wall 6 made of an insulating film is provided on a side section of the gate electrode 5.
Are formed.

Further, reference numeral 7 denotes an interlayer insulating film laminated on the entire surface of the semiconductor substrate 1 on which the components of the semiconductor element are formed, and 8 denotes a contact 8 formed from the surface of the interlayer insulating film 7 to the surface of the impurity region 3. The contact 8 includes a titanium nitride film 8a formed in contact with the interlayer insulating film 7 and the impurity region 3, and a titanium nitride film 8a.
a of the tungsten film 8b buried in the recessed portion.

Reference numeral 9 denotes a first metal wiring which is in contact with the upper surface of the contact 8 and is patterned on the surface of the interlayer insulating film 7, and 10 denotes an interlayer formed on the first metal wiring 9 and the interlayer insulating film 7. An insulating film 11 is a via hole formed from the upper surface of the interlayer insulating film 10 so as to be in contact with the first metal wiring 11, and the via hole 11 is, like the contact 8, a titanium nitride film 11a and a tungsten film 11b. It is composed of Further, reference numeral 12 is patterned on the surface of the interlayer insulating film 10 to form a via hole 11.
And the second metal wiring 13 in contact with the upper surface of the second metal wiring 12 and the passivation film formed on the surface of the interlayer insulating film 10, respectively.

The contact 8 and the via hole 11 shown in FIG. 1 are composed of a plurality of layers of a titanium nitride film 8a or 11a and a tungsten film 8b or 11b, and at least side surfaces of the contact 8 and the via hole 11 are thick. An alkali-resistant titanium nitride film 8a or 11a having a thickness of about 1000 ° is formed.

FIG. 2 is an enlarged view mainly showing the contact 8 and the first metal wiring 9 shown in FIG. While the cross section of FIG. 1 is along the wiring length direction of the first metal wiring 9,
The cross section of FIG. 2 shows the first metal wiring 9 along the wiring width direction. In FIG. 2, reference numeral 14 denotes a titanium silicide film formed on the bottom of the contact 8, and the same reference numerals as those already used for the description denote the same or corresponding parts.

The contact 8 formed as shown in FIG.
A titanium nitride film 8 a having a thickness of about 1000 ° is formed so as to surround the outer periphery of contact 8. Therefore, when the first metal wiring 9 which is a borderless wiring and has a wiring width almost the same as the diameter of the contact 8 is formed on the contact 8, even if the misalignment of the superposition occurs up to about 1000 °. Only a part of the titanium nitride film 8a, which is an alkali-resistant substance constituting the contact 8, is exposed, and the tungsten film 8b soluble in the strong alkaline etching solution is not exposed.

That is, when a strong alkaline etchant is used to remove a resist pattern used for patterning the first metal wiring 9 or a polymer which is a foreign substance generated when the resist pattern is removed by ashing, The contact 8 can be prevented from being melted out and resulting in poor connection.

Next, the manufacturing method of the semiconductor device shown in FIG. 2 will be described focusing on the connection between the contact 8 and the first metal wiring 9, which is a feature of the present invention. In the drawings for describing the manufacturing method, the description of the gate insulating film 4, the gate electrode 5, and the like, which are components for forming the MOS transistor, is omitted.

First, as shown in FIG. 3A, a LOCOS oxide film 2 is formed on a region to be an inactive region on the surface of a semiconductor substrate 1, and further, a gate insulating film 4 and a gate, which constitute a MOS transistor, are formed. An electrode 5, a sidewall 6, and the like are formed (the LOCOS oxide film 2, the gate insulating film 4, the gate electrode 5, and the sidewall 6 are not shown), and an interlayer insulating film 7 made of a silicon oxide film is formed thereon by 10,000 to 10,000. Fifteen
A film is formed to have a thickness of 000 °. Thereafter, the interlayer insulating film 7 is selectively anisotropically etched to form a contact hole 15 having an opening diameter of about 3000 ° reaching the surface of the impurity region 3. Impurity region 3
May be formed before the interlayer insulating film 7 is formed, or may be formed by implanting impurity ions after the contact hole 15 is opened. Note that the horizontal cross-sectional shape of the contact hole 15 is a circle or a shape close to the circle.

Next, as shown in FIG. 3B, the surface of the substrate to be processed (the semiconductor device in the manufacturing process is hereinafter referred to as a substrate to be processed) including the inner wall and the bottom surface of the contact hole 15 is sputtered. Alternatively, a titanium film 16 is laminated by a CVD method so as to have a thickness of about 200 °, and a titanium nitride film 8a is further formed thereon by a thermal CVD method using a mixed gas of TiCl ₄ and NH ₃ to a thickness of about 1000 °. It is laminated so that

Thereafter, as shown in FIG. 3 (c), a heat treatment is performed at a temperature of 800 ° C. for 30 seconds in a nitrogen atmosphere to change the titanium film 16 into titanium nitride 8a. In this heat treatment, on the bottom surface of the contact hole 15, silicon, which is a component of the semiconductor substrate 1, and the titanium film 16 react with each other to form a titanium silicide film 14.
Is formed.

Next, as shown in FIG. 3D, a tungsten film 8b is laminated on the surface of the substrate to be processed by using a blanket CVD method, and the inside of the contact hole 15 is completely covered with the tungsten film 8b. Buried in

Thereafter, as shown in FIG. 3E, the entire surface of the substrate to be processed is etched back, so that the upper surface of the interlayer insulating film 7 is exposed. Thereby, the titanium nitride film 8
a and the contact 8 comprising the tungsten film 8b is formed. When the horizontal section of the upper part of the contact 8 is viewed, the thickness of the titanium nitride film 8a surrounding the outer periphery of the contact 8 is 1000 ° or more.

Next, as shown in FIG. 3F, a metal film 9a which is an Al alloy
The layers are laminated so as to have a thickness of about 00 °. Then, FIG.
As shown in (g), a resist pattern 1 corresponding to the first metal wiring 9 (borderless wiring) is formed on the metal film 9a.
7 is formed.

Next, as shown in FIG. 3H, using the resist pattern 17 as an etching mask, a first metal wiring 9 for performing anisotropic etching on the metal film 9a is obtained.
Thereafter, as shown in FIG.
7 is removed using a strong alkaline etchant. Here, for example, 2-2 aminoethoxyethanol (60%) hydroxylamine (1
8%), water (17%), catechol (5%): strong alkali (pH = 12) is used. Further, a method of first removing the resist pattern 17 by performing ashing, and removing a polymer of a foreign substance generated at the time of patterning the first metal wiring 9 and adhering to the side cross section of the laminated wiring by using a strong alkaline etching solution. May be used. The resist pattern 17 was formed only by the strong alkaline etching solution.
Is removed, the polymer generated by the anisotropic etching is removed together with the resist.

Thereafter, by laminating the interlayer insulating film 10 on the substrate to be processed, a semiconductor device having the structure shown in FIG. 2 can be obtained. For simplicity, the description of the elements formed above the first metal wiring 9 is omitted.

As shown in the above manufacturing method, according to the manufacturing method of the semiconductor device, the semiconductor device is originally formed due to an error in photolithography at the stage of forming the resist pattern 17 serving as an etching mask shown in FIG. Even if the misalignment occurs within a range of 1000 ° or less from the desired position, the contact 8 has a two-layer structure of the titanium nitride film 8a and the tungsten film 8b, and has a thickness of 1000 ° or more from the outer periphery to the inside of the contact 8. Thus, a titanium nitride film 8a, which is an alkali-resistant substance, is formed.

Therefore, even when the resist pattern 17 is removed by using a strong alkaline etching solution, the material forming the contact 8 is notwithstanding the misalignment of the first metal wiring 9 and the contact 8. Is not eluted, and a good connection state can be obtained.

In the above description, only the connection portion between the contact 8 and the first metal wiring 9 has been described. However, as shown in FIG. Via hole 11 for electrically connecting
In the structure (2), similarly to the structure of the contact 8, the via hole 11 in a good connection state can be obtained by forming a two-layer structure including the titanium nitride film 11a and the tungsten film 11b. Note that, on the bottom surface of the via hole 11, a titanium-aluminum alloy film 18 which is a compound of aluminum which is a component of the first metal wiring 9 and titanium which is a component of the titanium nitride film 11a is formed.

The via hole 11 as shown in FIG. 4 can also be used in the case where the second metal wiring 12 and the via hole 11 are formed in a state in which the overlay displacement occurs as in the case of the contact 8. In this case, the elution of the substance constituting the via hole 11 can be suppressed even when a strong alkaline etching solution is used, and a good connection state can be obtained.

The thickness of the titanium nitride 8a forming the contact 8 is, for example, not less than 1000 ° from the top to the bottom of the contact hole 15, and the contact hole 15 is completely buried with the titanium nitride film 8a. It is not necessary to form it in such a state that the thickness is maintained such that it is not adhered to the inner wall and the bottom surface of the contact hole 15 at least, and if the thickness near the upper opening is 1000 mm or more, Even if the first metal wiring 9 formed thereover has a misalignment, it is another component of the contact 8, and a tungsten film 8b soluble in a strong alkaline solution is formed by this strong alkaline etching. Since there is no exposure to liquid, elution of the contact 8 can be suppressed. Even when the first metal wiring 9 is formed smaller than the dimension to be formed due to CD loss, the titanium nitride film 8a
Is provided, the first metal wiring 9 and the contact 8 can be in a good connection state.

The same can be said for the structure of the via hole 11. The titanium nitride film 11a constituting the via hole 11 is formed to have the same thickness from the top to the bottom of the opening with a thickness of 1000 ° or more. Even if it is not necessary, it is needless to say that a good connection state can be obtained even when combining the displacement of the superposition and the removal of the resist or the polymer with a strong alkaline etching solution. The connection between the contact or the via hole and the borderless wiring in the sub-quarter micron device can be satisfactorily performed by covering the outer periphery of the contact or the via hole with an alkali-resistant substance so as to have a thickness of 1000 mm or more.

Embodiment 2 Next, a second embodiment of the present invention will be described. FIG. 5 shows Embodiment 2 of the present invention.
2 is an enlarged cross-sectional view of the semiconductor device shown in FIG. 1 and shows a connection portion between a contact 8 and a first metal wiring 9 of the semiconductor device shown in FIG. 5, reference numeral 8c denotes a component of the contact 8, and denotes a tungsten nitride film interposed between the titanium nitride film 8a and the tungsten film 8b forming the contact 8. This tungsten nitride film 8c is an alkali-resistant substance,
It does not dissolve even when exposed to a strong alkaline etchant. Other reference numerals that are the same as those already used for the description indicate the same or corresponding parts.

The outer periphery of the contact 8 formed as shown in FIG. 5 is formed by being surrounded by a film composed of a titanium nitride film 8a and a tungsten nitride film 8c having a total thickness of about 1000 °. Therefore, contact 8
When a first metal wiring 9 having a wiring width almost the same as the diameter of the first metal wiring 9 is formed on the contact 8, even if the displacement of the superposition occurs by about 1000 ° at the maximum, the alkali resistance constituting the contact 8 Titanium nitride film 8a and alkali-resistant tungsten nitride film 8
Only a part of c is exposed, and the tungsten film 8b soluble in the strong alkaline etching solution is not exposed.

That is, when a strong alkaline etchant is used to remove a resist pattern used for patterning the first metal wiring 9 or a polymer which is a foreign substance generated when the resist pattern is removed by ashing, the contact 8 Can be suppressed from being eluted by the conductive material constituting the above, and a good connection state can be obtained.

Next, a description will be given of a method of manufacturing the semiconductor device shown in FIG. 5, focusing on the connection between the contact 8 and the first metal wiring 9, which is a feature of the present invention. As in the case of the first embodiment, in the drawings for describing the manufacturing method, the description of the gate insulating film 4, the gate electrode 5, and the like, which are the components for forming the MOS transistor, is omitted.

First, as shown in FIG. 6A, as in the case shown in FIG. 3A of the first embodiment, an interlayer insulating film 7 laminated on the semiconductor substrate 1 has an opening diameter of about 3000 °. The contact hole 15 is opened, and the impurity region 3 is formed. Further, a 200-degree titanium film and a 1000-degree titanium nitride film are sequentially laminated on the entire surface of the interlayer insulating film 7 by sputtering. At this time, a titanium film and a titanium nitride film having a thickness of about 30% of the inner wall and the bottom of the contact hole 15 are laminated. Further, a heat treatment is performed at 800 ° C. for 30 seconds in a nitriding atmosphere to form a titanium nitride film 8a having a thickness of about 1000 °. During this heat treatment, titanium located at the bottom of the contact hole 15 reacts with silicon constituting the semiconductor substrate 1 to form a titanium silicide film 14.

Next, as shown in FIG. 6B, a tungsten film 19 having a thickness of 1000.degree. Or more is formed using a blanket CVD method so as not to bury the contact hole 15. Laminate over the entire surface.

Thereafter, as shown in FIG. 6C, the substrate to be processed is placed in a nitriding atmosphere such as an NH ₃ atmosphere, and
A heat treatment is performed at 0 ° C. for about 1 minute to form a tungsten film 19.
To obtain a tungsten nitride film 8c. Even when the tungsten nitride film 8c is formed, it is necessary to adjust the thickness of the tungsten film 19 in advance so that the inside of the contact hole 15 is not buried.
As another method of nitriding the tungsten film 19, N
There is a method in which plasma processing is performed in an H ₃ atmosphere (1 Torr) at RF = 100 W for 1 minute, and the plasma processing may be performed while heating the semiconductor substrate 1.

Next, as shown in FIG. 6D, a tungsten film 8b is laminated on the entire surface of the substrate to be processed by using the blanket CVD method, and the inside of the contact hole 15 is completely filled with a conductive material. And

Thereafter, as shown in FIG. 6E, the entire surface is etched back from the front side of the substrate to be processed until the upper surface of the interlayer insulating film 7 is exposed, and the titanium nitride film 8a, the tungsten nitride film 8c, the tungsten The contact 8 made of three kinds of conductive films of the film 8b is obtained.

Next, as shown in FIG. 6F, a metal film 9a to be the first metal wiring 9 is laminated on the entire surface of the substrate to be processed, as in the case of the first embodiment. FIG.
As shown in (g), the first metal wiring 9 is formed by photolithography.
The resist pattern 17 having a shape (borderless wiring) corresponding to the above is patterned. It is assumed that the resist pattern 17 is formed not at a position where the contact 8 completely overlaps, but partially at a position that does not overlap with the contact 8 and is shifted up to about 1000 ° due to misalignment.

Thereafter, as shown in FIG. 6H, anisotropic etching is performed on the metal film 9a using the resist pattern 17 as an etching mask to obtain a first metal wiring 9.
Further, as shown in FIG.
Is removed using a strong alkaline etching solution. Also,
As another method, first, the resist pattern 17 is removed by performing oxygen plasma ashing, and a polymer of a foreign substance generated at the time of patterning the first metal wiring 9 and adhering to the side section of the stacked wiring is removed with a strong alkaline etching solution. There is a method for removal using either method, and either method may be used.

Since the total thickness of the titanium nitride film 8a and the tungsten nitride film 8c, which are the alkali-resistant substances forming the contact 8, is 1000 ° or more,
Even if the resist pattern 17 is formed so as to have a misalignment, and the first metal wiring 9 formed using the resist pattern as an etching mask is formed reflecting the misalignment, the maximum misalignment is 1000 °. It is about.
Therefore, even when exposed to a strongly alkaline etching solution, the tungsten film 8b soluble in this etching solution is not exposed, and a contact 8 having a good shape can be finally obtained. Thereafter, a semiconductor device as shown in FIG. 5 can be obtained through a step of laminating the interlayer insulating film 10.

When the first metal wiring 9 is formed to have a wiring width smaller than a dimension to be formed due to CD loss, strong alkaline etching is performed with a part of the contact 8 exposed. Even if the processing using the liquid is performed, the portion exposed due to the deviation between the first metal wiring 9 and the contact 8 is constituted by the titanium nitride film 8a and the tungsten nitride film 8c, which are alkali-resistant substances. The conductive material constituting the contact 8 is not eluted, and good electrical connection can be achieved.

As shown in FIG. 7, similarly to the case described in the first embodiment, the structure of via hole 11 can be formed in the same manner as the structure of contact 8 shown in FIG. In FIG. 7, reference numeral 11c denotes a tungsten nitride corresponding to the tungsten nitride 8c constituting the contact 8, and the same reference numerals as those already used for the description denote the same or corresponding parts. The second metal wiring 12 and the via hole 11 are in a good connection state, and even if a misalignment occurs between them, a part of the via hole 11 is eluted due to the strong alkaline etching solution. No problem occurs, and a good connection state can be obtained.

The structure of the contact 8 (or the via hole 11) of the second embodiment differs from the structure of the via hole 11 (or the contact 8) already shown in the first embodiment.
Needless to say, it is also possible to combine the above structures and use them in one semiconductor device.

Embodiment 3 Next, a third embodiment of the present invention will be described. FIG. 8 shows Embodiment 3 of the present invention.
FIG. 1D is a cross-sectional view of the semiconductor device shown in FIG. 1. In the figure, reference numeral 8 d denotes a titanium tungsten film interposed between a titanium nitride film 8 a and a tungsten film 8 b constituting the contact 8. The film 8d is an alkali-resistant substance. In addition, the same reference numerals as those already used for the description indicate the same or corresponding parts.

The total thickness (horizontal thickness) of the titanium nitride film 8a and the titanium tungsten film 8d constituting the contact 8 shown in FIG. 8 above the contact.
Is characterized in that it is formed to be larger than a value of about 1000 ° which is the maximum value of the overlay deviation that can occur in the sub-quarter micron device.

Next, a method of manufacturing the semiconductor device shown in FIG. 8 will be sequentially described with reference to FIG. First, as in the case of the second embodiment, a contact hole 15 having an opening diameter of about 3000 ° is opened in the interlayer insulating film 7 on the semiconductor substrate 1, and the upper surface of the interlayer insulating film 7 including the inner wall and the bottom surface of the contact hole 15. Then, a titanium nitride film 8a is formed. The impurity region 3 is formed before the formation of the titanium nitride film 8a. The thickness of the titanium nitride film 8a formed on the inner wall of the contact hole 15 is about 360 °.

Further, a blanket CV is placed on the substrate to be processed.
Tungsten film 19 having a thickness of about 700 ° by D method
Then, a titanium film 20 having a thickness of about 700 ° is formed by sputtering or CVD. After the formation of the titanium film 20, the contact hole 15 is formed.
The inside is not completely buried, but has a cavity.

Next, as shown in FIG.
A heat treatment is performed in a nitrogen atmosphere of about 20 minutes to cause the tungsten film 19 and the titanium film 20 to react with each other to form a titanium tungsten film 8d. This titanium tungsten film 8d
Is set to a value of at least 1000 ° in the horizontal dimension of the opening end of the contact hole 15. When the titanium tungsten film 8d is formed, the thickness is adjusted so that the inside of the contact hole 15 is not completely filled.

Thereafter, as shown in FIG. 9C, a tungsten film 8b is formed on the surface of the substrate to be processed by a blanket CVD method, and the inside of the contact hole 15 is buried with a conductive material. Next, as shown in FIG. 9D, the entire surface is etched back to expose the surface of the interlayer insulating film 7,
Titanium nitride film 8a and titanium tungsten film 8
The contact 8 made of d and the tungsten film 8b is formed.

Then, as in the first and second embodiments, FIG.
As shown in FIG. 9E, a metal film 9a to be the first metal wiring 9 is laminated on the surface of the interlayer insulating film 7, and as shown in FIG. A resist pattern 17 having a shape corresponding to the metal wiring 9 is patterned by photolithography. Here, it is assumed that when the resist pattern 17 is formed, a displacement of a maximum of about 1000 ° occurs from a position where the resist pattern 17 is originally formed due to the displacement of the superposition.

Next, as shown in FIG. 9G, patterning is performed on the metal film 9a using the resist pattern 17 as an etching mask, thereby obtaining the first metal wiring 9 in which the misalignment has occurred. Thereafter, as shown in FIG. 9H, the resist pattern 1 used as an etching mask was used.
7 is removed using a strong alkaline etching solution, or the resist pattern 17 is first removed by ashing to remove foreign matter generated at the time of patterning the first metal wiring 9 and adhering to the side cross section of the laminated wiring. Either method of removing the polymer using a strong alkaline etchant may be used.

As in the prior art, when an alkali-resistant film (for example, a titanium nitride film) having a thickness smaller than the overlap deviation is formed on the outer peripheral portion of the contact, a part of the tungsten film is formed. There was a problem that the first metal wiring did not overlap with the first metal wiring and was exposed, and tungsten was eluted from this portion by a strong alkaline etching solution.

However, the structure of the contact 8 according to the third embodiment has a thickness of 1
By having an alkali-resistant conductive film (titanium nitride film 8a and titanium tungsten film 8d) with a film thickness larger than about 000 °, that is, larger than the size of the misalignment, it can be used with a strong alkaline etching solution. And the soluble tungsten film 8b is not exposed during the treatment with the strong alkaline etching solution. Therefore, even when a misalignment occurs, a portion of the contact 8 is not eluted by the strong alkaline etchant used for removing the resist pattern 17 and a good connection between the first metal wiring 9 and the contact 8 is obtained. The state can be obtained.

The thickness in the horizontal direction of the titanium nitride film 8a and the titanium tungsten film 8d, which are the alkali-resistant substances forming the contact 8, is the film thickness above the contact 8, ie, at the opening end of the contact hole 15. The thickness at the position deeper than the bottom surface and the opening end of the contact 8 is not limited to about 1000 °.

As shown in FIG. 10, the structure of the contact 8 shown in FIGS. 8 and 9 and the manufacturing method thereof can be applied to the via hole 11 of the semiconductor device shown in FIG. 10, reference numeral 11d denotes a titanium tungsten film, and this titanium tungsten film 11d is the titanium tungsten film 8d of FIG.
Is equivalent to In addition, the same reference numerals as those already used for the description indicate the same or corresponding parts.

Even in the case where misalignment occurs between the second metal wiring 12 and the via hole 11, when a strong alkaline etching solution is used in the manufacturing process,
Tungsten film 11 as a component of via hole 11
b is not exposed, and the via hole 11 and the second metal wiring 12 can be in a good connection state.

The structure of the contact 8 (or via hole 11) of the third embodiment and the structure of the first and second embodiments
It is needless to say that any of the structures of the via hole 11 (or the contact 8) shown in the above can be combined and used in one semiconductor device.

Embodiment 4 Next, a fourth embodiment of the present invention will be described. FIG. 11 is a sectional view of a semiconductor device according to a fourth embodiment of the present invention. In FIG. 11, reference numeral 21 denotes a titanium tungsten film, which is formed by forming a film made of titanium on tungsten which is a component of the contact 8 and applying a heat treatment thereto. Reference numeral 22 denotes a titanium film formed on the surface of the interlayer insulating film 7 for forming the titanium tungsten film 21, which adheres to the bottom surface of the first metal wiring 9 even after the formation of the first metal wiring 9. It remains in the state. In addition, among the reference numerals already used for the description, the same reference numerals indicate the same or corresponding parts.

In the fourth embodiment, as shown in FIG. 11, a titanium tungsten film 21 is formed on the upper portion, and the contact 8 and the first metal wiring 9 are electrically connected through the film. Thus, even if the displacement of the first metal wiring 9 and the contact 8 is as large as about 1000 ° at the maximum, a good connection state can be obtained.

Next, a method of manufacturing the semiconductor device of FIG. 11 will be described with reference to FIG. First, as shown in FIG. 12 (a), an interlayer insulating film 7 is laminated on a semiconductor substrate 1, a contact hole is opened, and titanium adhered to at least the side wall of the contact hole as in the second embodiment. The nitride film 8a is formed so as to have a thickness of about 360 °. The silicon and titanium of the semiconductor substrate 1 react by the heat treatment at this time, and a titanium silicide film 14 is formed on the bottom surface of the contact hole. Next, a tungsten film 8b is formed, and the inside of the contact hole is filled with the tungsten film 8b. Thereafter, etch back is performed until the surface of the interlayer insulating film 7 is exposed, thereby obtaining a contact 8.

Thereafter, as shown in FIG. 12B, a titanium film 22a is laminated on the surface of the substrate to be processed to a thickness of about 500 ° by a sputtering method. next,
As shown in FIG. 12C, a heat treatment is performed at a temperature of 700 ° C. for about 20 minutes in an atmosphere in which the surface of the titanium film 22a is not oxidized, for example, in an argon atmosphere which is an inert gas. By this heat treatment, the titanium tungsten film 21 is formed at the contact portion between the tungsten 8b and the titanium film 22a.
Is formed.

Thereafter, as shown in FIG. 12D, a metal film 9a to be the first metal wiring 9 is laminated. Next, FIG.
As shown in FIG. 2E, a resist pattern 17 corresponding to the first metal film 9 is formed on the surface of the metal film 9a by a photoengraving process. The deviation of the overlapping of the resist pattern 17 and the contact 8 is about 1000 ° at the maximum.

Thereafter, as shown in FIG. 12F, anisotropic etching is performed on the metal film 9a using the resist pattern 17 as an etching mask to obtain a first metal wiring 9. At this stage, by selectively nitriding the cross section of the titanium film 22 to make it an alkali-resistant substance, elution of the titanium film 22 in the next strong alkaline etching solution treatment can be completely suppressed. Next, FIG.
As shown in (2), the resist pattern 17 is removed using a strong alkaline etching solution. Alternatively, first, the resist pattern 17 is removed by performing ashing,
A method of removing a polymer of a foreign substance generated at the time of patterning the first metal wiring 9 and adhering to a side cross section of the stacked wiring by using a strongly alkaline etching solution may be used.

As described above, even when the contact 8 and the first metal wiring 9 are misaligned, the titanium tungsten film 21 which is an alkali-resistant substance is formed on the contact 8. This prevents the tungsten film 8b, which is soluble in alkali, from being exposed to the etching solution. Therefore, it is possible to form a good connection state between the first metal wiring 9 and the contact 8 without the problem of elution of tungsten.
Also, even when the first metal wiring 9 is formed to have a small size due to CD loss, good connection with the contact 8 is similarly enabled.

The structure of the fourth embodiment is different from the structures of the other embodiments described above. The entire upper surface of the contact 8 in the horizontal direction is covered with an alkali-resistant substance. It is possible to cover a large overlap deviation, and to make the contact 8 and the first metal wiring 9 electrically favorable.

Further, by adopting the structure as in the fourth embodiment, it is possible to interpose a titanium film 22 between the first metal wiring 9 and the interlayer insulating film 7, so that the adhesion between the two is possible. There is an effect that the performance can be improved.

As shown in FIG. 13, the structure of the via hole 11 which is a component of the semiconductor device of FIG.
The structure of one contact 8 can be applied.
In FIG. 13, reference numeral 23 corresponds to the titanium tungsten film 21 in FIG. 11, and reference numeral 24 denotes a film corresponding to the titanium film 22. In addition, the same reference numerals as those already used for the description indicate the same or corresponding parts.

By forming the via hole 11 as shown in FIG. 13, the second metal wiring 12 and the via hole 11 are formed.
When a strong alkaline etchant is used in the manufacturing process, the tungsten film 11b, which is a component of the via hole 11, is not exposed even when the superposition misalignment occurs. And a good connection state with the metal wiring 12.

The structure of the contact 8 (or the via hole 11) of the fourth embodiment is different from that of the first to third embodiments.
It is needless to say that the structure of the via hole 11 (or the contact 8) shown in the above can be combined and used in one semiconductor device.

Embodiment 5 FIG. Next, a fifth embodiment of the present invention will be described. FIG. 14 is a sectional view of the semiconductor device of the fifth embodiment. In the figure, reference numeral 25 denotes a tungsten nitride film obtained by nitriding the upper part of the tungsten film 8b constituting the contact 8, and
Among the symbols used for the description, the same symbols are the same,
Or it shows a corresponding part.

As shown in FIG. 14, a tungsten nitride film 25 is formed by nitriding the entire surface of the tungsten film 8b located above the contact 8, and the first metal wiring 9 is formed by alkali resistance. The conductive material forming the contact 8 is prevented from being eluted even when exposed to a strong alkaline etching solution used for etching removal of the resist pattern used for patterning.

Therefore, the contact 8 and the first metal wiring 9
Also, when a misalignment is caused by the superposition, a substance soluble in the strong alkaline etching solution
The contact 8 having a good shape can be obtained without being exposed to the etchant, and the contact 8 and the first metal wiring 9 can be in a good connection state via the tungsten nitride film 25. is there.

Next, a method for forming a semiconductor device as shown in FIG. 14 will be described with reference to FIG. First, FIG.
As shown in FIG. 12, a contact 8 is formed as in the case shown in FIG. 12A of the fourth embodiment. Then, FIG.
As shown in (b), a nitriding treatment is performed at a temperature of 700 ° C. for 1 minute in an NH ₃ atmosphere, and the entire upper surface of the tungsten film 8b constituting the contact 8 is changed to a tungsten nitride film 25 which is an alkali-resistant substance. Let it. By using the tungsten nitride film 25 as a component of the contact 8, the upper portion of the contact 8 can be made completely alkali resistant. The tungsten nitride film 25 is formed, for example, by N
It can also be implemented by performing a plasma treatment for 1 minute at RF = 100 W in an H ₃ atmosphere (1 Torr).

Next, as shown in FIG. 15C, a metal film 9a to be the first metal wiring 9 is laminated on the entire surface.
On the upper part, a resist pattern 17 having a shape corresponding to the first metal wiring 9 is formed by photolithography. The resist pattern 17 is formed with a maximum deviation of about 1000 ° due to a deviation of the superposition generated during photolithography.

Thereafter, as shown in FIG. 15D, the metal film 9a is formed using the resist pattern 17 as an etching mask.
Is performed on the first metal wiring 9 by patterning. Next, as shown in FIG.
The resist pattern 17 is removed using a strong alkaline etching solution. Thereafter, an interlayer insulating film 10, a via hole 11, a second metal wiring 12, and the like are formed to form FIG.
Further, a semiconductor device as shown in FIG. 1 can be obtained.

The method of removing the resist pattern 17 is not limited to the strong alkaline etching solution alone. First, the resist pattern 17 is removed by performing oxygen plasma ashing, and is generated at the time of patterning the first metal wiring 9. A method of removing a polymer which is a foreign substance adhering to a side cross section of the laminated wiring by using a strong alkaline etching solution may be used.

If the upper part of the contact 8 is soluble in a strong alkaline etchant, the contact 8 is dissolved by the elution of the tungsten film 8b or the like constituting the contact 8.
And the first metal wiring 9 cannot be connected well. However, by employing the structure of the fifth embodiment, the upper portion of the contact 8 can be made completely alkali-resistant, and the conductive material can be completely buried even when a treatment using a strong alkaline etching solution is performed. Contact 8 can be obtained. Also, the first metal wiring 9 is CD
Even in the case of a small size due to loss, good connection with the contact 8 is similarly enabled.

Further, as shown in FIG. 16, the structure of the contact 8 having the structure shown in FIG. In FIG. 16, reference numeral 26 denotes an alkali-resistant tungsten nitride film which is a component of the via hole 11, and the same reference numerals as those already used for the description denote the same or corresponding parts.

The semiconductor device formed as shown in FIG.
Via hole 11 having a structure including tungsten nitride film 26
Is formed, even if the second metal wiring 12 is formed in a state where the second metal wiring 12 is misaligned with the via hole 11, the conductive material constituting the via hole 11 is eluted by the strong alkaline etching solution. Therefore, the via hole 11 and the second metal wiring 12 can be in a good connection state. The contact 8 or the via hole 1 having the structure shown in FIGS.
The structure 1 is not limited to a semiconductor device of a sub-quarter micron device, and can be applied to a semiconductor device of another design rule.

The structure of the contact 8 (or the via hole 11) of the fifth embodiment is different from that of the first to fourth embodiments.
It is needless to say that the structure of the via hole 11 (or the contact 8) shown in the above can be combined and used in one semiconductor device.

Embodiment 6 FIG. Next, a sixth embodiment of the present invention will be described. FIG. 17 is a sectional view of a semiconductor device according to the sixth embodiment. In the figure, reference numeral 27 denotes a conductive film constituting the contact 8, a titanium film adhered to the side wall and the bottom surface, and 28 denotes a tungsten nitride film formed by nitriding the upper part of the tungsten film 8 b constituting the contact 8. Reference numeral 29 denotes a titanium nitride film formed by nitriding the upper portion of the titanium film 27. In addition, the same reference numerals as those already used for the description denote the same or corresponding parts. is there.

By adopting the structure of the contact 8 as shown in FIG. 17, even if the first metal wiring 9 is formed in a state where the first metal wiring 9 is displaced from the contact 8, it is used in the formation process. Even when the contact 8 is exposed to a strong alkaline etching solution, the conductive material as a component of the contact 8, for example, the tungsten film 8b is not eluted, and a good connection state can be obtained.

Next, a method of manufacturing the semiconductor device of the sixth embodiment will be described with reference to FIG. First, FIG.
As shown in FIG. 7, a contact hole is formed in the interlayer insulating film 7 on the semiconductor substrate 1 in the same manner as in the manufacturing method shown in the other embodiments. The opening diameter of this contact hole is 3000
Å Next, a titanium film 27 and a titanium nitride film 8 are formed on the surface of the interlayer insulating film 7 by sputtering.
a so as to have a film thickness of about 200 °,
Further, the tungsten film 8b is 5,000
The contact hole is buried so as to have a film thickness of about Å. On the side wall and bottom of the contact hole,
The film laminated by the sputtering method is an interlayer insulating film 7
A film having a film thickness smaller than the film thickness laminated on the upper surface of is formed.

Next, as shown in FIG. 18B, the whole surface is etched back using the interlayer insulating film 7 as an etching stopper, and the tungsten film 8b, the titanium nitride film 8a, and the titanium film 27 are sequentially anisotropically etched. . Thus, the contact 8 including the titanium film 27, the titanium nitride film 8a, and the tungsten film 8b is obtained.

Thereafter, as shown in FIG. 18C, in order to prevent the titanium film 27 soluble in the strong alkaline etching solution from being exposed on the surface of the contact 8, the surface of the substrate to be processed is removed. For example, 400 ° C. in a nitrogen atmosphere
Anneal at a temperature of about 15 minutes to change the upper part of the titanium film 27 to a titanium nitride film 29. At this time, the upper portion of the tungsten film 8b is also nitrided at the same time, and a tungsten nitride film 28 is formed.

Next, as shown in FIG. 18D, a metal film 9a to be the first metal wiring 9 is laminated on the surface of the substrate to be processed, and further, the surface corresponds to the first metal wiring 9 A resist pattern 17 having a desired shape is formed by photolithography. At this time, it is assumed that the resist pattern 17 is formed in a state where the resist 8 is misaligned with respect to the contact 8.

Thereafter, as shown in FIG. 18E, the metal film 9a is formed using the resist pattern 17 as an etching mask.
Is anisotropically etched to obtain a first metal wiring 9. Since the first metal wiring 9 is formed so as to have the same arrangement shape as the resist pattern 17, the first metal wiring 9 is formed so as to have a misalignment similar to the resist pattern 17.

Next, the resist pattern 17 is removed using a strong alkaline etching solution. As another resist removal method, first, the resist pattern 17 is removed by performing oxygen plasma ashing, and a polymer of a foreign substance which is generated at the time of patterning the first metal wiring 9 and adheres to the side section of the stacked wiring is strongly alkaline-etched. A method of removing with a liquid may be used.

Using a strong alkaline etching solution, the upper portion of the contact 8 is partially exposed to this etching solution.
A substance which is soluble in a strongly alkaline etchant is subjected to a nitriding treatment in advance to form a titanium nitride film 29 and a tungsten nitride film 28, respectively, thereby suppressing elution of a part of the contact 8. As a result, a good connection between the contact 8 and the first metal wiring 9 can be obtained. Also, the first metal wiring 9 is CD
Even in the case of a small size due to loss, good connection with the contact 8 is similarly enabled.

Further, as shown in FIG. 19, the structure of the contact 8 in FIG. In FIG. 19, reference numeral 30 denotes a via hole 1
1 is a titanium film, 31 is a tungsten nitride film obtained by nitriding the upper part of the tungsten film 8b, and 32 is a titanium nitride film obtained by nitriding the upper part of the titanium film 30. Is shown.

As shown in FIG. 19, when a misalignment occurs between the via hole 11 and the second metal wiring 12, the upper surface of the via hole 11 is not affected by the processing using a strong alkaline etching solution. Is covered with the titanium nitride films 11a, 32 and the tungsten nitride film 31, which are alkali-resistant substances, so that the elution of the via hole 11 can be suppressed, and a good connection state can be obtained.

Further, for example, the structure of the contact 8 (or the via hole 11) of the sixth embodiment is combined with the structure of the via hole 11 (or the contact 8) already shown in the first to fifth embodiments to form one semiconductor. Needless to say, it can be used for the device.

Embodiment 7 FIG. Next, a semiconductor device according to a seventh embodiment of the present invention will be described. FIG. 20 is a cross-sectional view of the semiconductor device according to the seventh embodiment.
Is an alkali-resistant conductive material constituting the contact 8, obtained by nitriding the tungsten film 8 b on the contact 8 at a portion not overlapping the first metal wiring 9 on the contact 8. It is.

Since the tungsten nitride film 33 is formed before the removal of the resist pattern used for patterning the first metal wiring 9, that is, before the contact 8 is exposed to the strong alkaline etching solution, it is soluble in the strong alkaline etching solution. The tungsten film 8b is not exposed to the etchant, the contact 8 having a good shape can be obtained, and a good connection state between the contact 8 and the first metal wiring 9 can be obtained. .

A method of manufacturing the semiconductor device having the structure shown in FIG. 20 will be described according to the manufacturing steps with reference to FIG. First, a contact 8 including a titanium nitride film 8a and a tungsten film 8b is formed in accordance with the manufacturing process shown in FIG. 12A of the fourth embodiment, and patterning is performed on the metal film using the resist pattern 17 as an etching mask. Then, as shown in FIG. 21A, a first metal wiring 9 is formed so as to overlap the contact 8. The first metal wiring 9 is formed in a state in which the disposition of the resist pattern 17 with respect to the contact 8 is affected by the displacement of the resist pattern 17 during photolithography.

Thereafter, as shown in FIG. 21B, plasma treatment is performed in a nitriding atmosphere, and the exposed tungsten film 8b is nitrided to form a tungsten nitride film 33. This tungsten nitride film 33 is an alkali-resistant conductive material.

Next, as shown in FIG. 21C, the resist pattern 17 is removed using a strong alkaline etching solution. As another method, first, the resist pattern 17 is removed by performing oxygen plasma ashing, and a polymer of a foreign substance which is generated at the time of patterning the first metal wiring 9 and adheres to a side section of the stacked wiring is strongly alkaline-etched. Either method of removing using a liquid may be used.

When the resist or the polymer is removed using the strong alkaline etching solution, the upper portion of the contact 8 is exposed to the etching solution due to the misalignment. However, since the tungsten nitride film 33 is formed, the contact 8 is removed. Elution can be suppressed, and a good connection state between the contact 8 and the first metal wiring 9 can be obtained.
Also, even when the first metal wiring 9 is formed to have a small size due to CD loss, good connection with the contact 8 is similarly enabled.

Further, as shown in FIG.
Can be applied to the bi-hole 11.
In FIG. 22, reference numeral 34 denotes a tungsten nitride film, which is a film corresponding to the tungsten nitride film 33 in FIG. In addition, the same reference numerals as those already used for the description indicate the same or corresponding parts.

The tungsten film 11b corresponding to the portion above the via hole 11 and not overlapping with the second metal wiring 12 is selectively nitrided to form a tungsten nitride film 34.
Is converted into an alkali-resistant substance. Therefore, the tungsten film 11 which is a component of the via hole 11 during the processing using the strong alkaline etching solution
It is possible to obtain a good connection state between the second metal wiring 12 and the via hole 11 without eluting b.

A method of selectively nitriding a portion corresponding to a misalignment between a contact and a metal wiring formed thereon is described in the contact 8 or via hole 11 having the structure shown in FIG. 20 or FIG. Further, the present invention is not limited to the wirings connected to them, for example, in the sixth embodiment.
And the metal wiring structure having a titanium film in the lowermost layer.

FIG. 23 shows a structure similar to contact 8 shown in the sixth embodiment.
A titanium film 35 is formed as a close contact layer on the bottom surface of the first metal wiring 9 connected to. In addition, reference numeral 28a denotes a tungsten nitride film formed by selectively nitriding the tungsten film 8b forming the contact 8, 29a denotes a titanium nitride film formed by nitriding the titanium film 27 forming the contact 8, 35a Is the first metal wiring 9
The side cross section of the titanium film 35 on the bottom surface of FIG. 3 shows a titanium nitride film formed by selectively nitriding, and the same reference numerals as those already used for the description denote the same or corresponding parts. is there.

When the first metal wiring 9 and the titanium film 35 are patterned by using the resist pattern as an etching mask, even if the contact 8 and the first metal wiring 9 are misaligned, the plasma may be generated in a nitriding atmosphere. By forming the tungsten nitride film 28a and the titanium nitride films 29a and 35a through the processing step, the contact 8, the first metal wiring 9, and the exposed portion of the titanium film 35 can be made of an alkali-resistant substance. Therefore, even if the resist pattern serving as the etching mask is removed using a strong alkaline etching solution, the contact 8, the first metal wiring 9, and the titanium film 35 are not eluted.
It is possible to obtain a good connection state.

Further, adopting the structure as shown in FIG. 23 also has the effect of improving the adhesion between the first metal wiring 9 and the interlayer insulating film 7 by forming the titanium film 35.
It is needless to say that the structure shown in FIG. 23 can be adapted to the via hole 11 to obtain a good connection state between the via hole 11 and the second metal wiring 12.

The structure of the contact 8 (or the via hole 11) of the seventh embodiment and the structure of the first to sixth embodiments have already been described.
Can be used in one semiconductor device by combining the structures of the via holes 11 (or contacts 8). Further, similarly to the case of the seventh embodiment shown in FIG. 23, a titanium film 35 is added as an adhesion layer to the already described wiring structures of the first to sixth embodiments, and a titanium nitride film is formed in a cross section. It is needless to say that the formation of 35a and alkali resistance make it possible to improve the adhesion between the lower interlayer insulating film and the wiring.

Embodiment 8 FIG. Next, an eighth embodiment of the present invention will be described. Embodiments 1 to 7 already described
In the structure of (1), the contact 8 or the via hole 11 is formed by entirely laminating a conductive material in the opening and on the surfaces of the interlayer insulating films 7 and 10, and thereafter, etch back to the surface of the interlayer insulating films 7 and 10. The contact 8 and the via hole 11 buried inside the opening were respectively formed. In the semiconductor device according to the eighth embodiment, a conductive material serving as a contact 8 is buried and, at the same time, an interlayer insulating film 7 is formed.
Among the conductive materials laminated on the surface of the semiconductor device, a film other than the tungsten film is not completely removed, and is used in a state where a part thereof is left on the interlayer insulating film.

FIG. 24 is a sectional view of a semiconductor device according to the eighth embodiment. In FIG. 24, reference numerals 27aa and 8aa
Are the constituent elements of the contact 8, the titanium film and the titanium nitride film formed so as to adhere to the bottom surface of the first metal wiring 9 on the surface of the interlayer insulating film 7, and 8bb is embedded in the interlayer insulating film 7. Tungsten film 35aa indicates a titanium nitride film obtained by selectively nitriding a side cross section of a titanium film 27aa laminated on the surface of the interlayer insulating film 7, and other symbols used in the description above. The same reference numerals indicate the same or corresponding parts.

In a semiconductor device having a structure as shown in FIG. 24, when a resist or a polymer is removed using a strong alkaline etching solution in the manufacturing process, a titanium film 27aa and a tungsten film 8bb that are soluble in the etching solution are removed. In order not to be exposed, the periphery of the tungsten film 8bb is completely covered with the titanium nitride film 8aa and the first metal wiring 9, and the exposed portion of the titanium film 27aa is selectively nitrided to obtain an alkali-resistant titanium nitride film. The ride film 35aa is used.

Next, a method of manufacturing the semiconductor device of FIG. 24 will be described with reference to FIG. First, as shown in FIG. 25A, a titanium film 27aa having a thickness of about 200 ° is formed on a surface of an interlayer insulating film 7 having a contact hole opening diameter of about 3000 ° formed on the semiconductor substrate 1 by sputtering. , A titanium nitride film 8aa having a thickness of about 500 ° is sequentially laminated. In addition, CV
Tungsten film 8 having a thickness of about 5000 ° by method D
The contact holes formed in the interlayer insulating film 7 are completely buried with a conductive material. Note that the thickness of the film to be laminated is a thickness on the surface of the interlayer insulating film 7, and is smaller than the film thickness to be laminated on the surface of the interlayer insulating film 7 on the inner wall and the bottom surface of the contact hole by the sputtering method. A film having a thickness is stacked.

Thereafter, as shown in FIG. 25B, the tungsten film 8bb is etched back using the titanium nitride film 8aa as an etching stopper, leaving the tungsten film 8bb only inside the interlayer insulating film 7.
The contact 8 including the titanium film 27aa, the titanium nitride film 8aa, and the tungsten film 8bb is obtained.

Next, as shown in FIG. 25C, a metal film 9a made of an aluminum alloy is laminated on the substrate to be processed to a thickness of about 4000 ° by a sputtering method. Further, as shown in FIG. 25D, a resist pattern 17 having a shape corresponding to the first metal wiring 9 is formed on the substrate to be processed by photolithography.

Then, as shown in FIG. 25E, the metal film 9a, the titanium nitride film 8aa, and the titanium film 8aa are sequentially anisotropically using the resist pattern 17 as an etching mask and the interlayer insulating film 7 as an etching stopper. The first metal wiring 9 is obtained by etching. By performing this anisotropic etching, the polymer 36 is generated as a foreign substance, and adheres to the side cross section of the laminated wiring formed by patterning.

Next, as shown in FIG. 25F, the resist pattern 1 is formed by performing oxygen plasma ashing.
7 is removed. Further, at a temperature of 400 ° C., nitrogen (NH
₃ ) By performing annealing for 15 minutes in an atmosphere, a side section of the exposed titanium film 27aa is nitrided to selectively form a titanium nitride film 35aa. This nitriding can also be performed by exposing to nitrogen plasma.

Thereafter, as shown in FIG. 25 (g), the polymer 36 is removed by using a strong alkaline etchant. Specifically, 2-2 aminoethoxyethanol (60
%) Hydroxylamine (18%), water (17%) catechol (5%): 6 with strong alkali (pH = 12)
A removal treatment is performed at 0 ° C. for 30 minutes to peel and remove the polymer 36. Thereafter, the semiconductor device as shown in FIG. 24 can be obtained by forming the interlayer insulating film 10 and the like.

Even when the treatment using a strong alkaline etching solution for removing the polymer is performed, nitriding treatment is performed before infiltrating into the etching solution to selectively remove the titanium film 27aa soluble in the alkaline etching solution. Since the titanium nitride film 35aa is changed to the alkali-resistant titanium nitride film 35aa, the elution of the conductive material constituting the wiring or the connection portion (contact) can be suppressed. Therefore,
A good connection between the contact 8 and the first metal wiring 9 can be obtained. Also, the first metal wiring 9 is CD
Even in the case of a small size due to loss, good connection with the contact 8 is similarly enabled.

In addition to the removal of the resist pattern 17 by the method shown in FIGS. 25 (e) to 25 (g), the removal of the resist pattern 17 and the polymer 36 simultaneously using a strong alkaline etching solution. There is also. In this case, after the first metal wiring 9 is obtained by anisotropic etching so that the titanium film 27aa is not exposed to the strong alkaline etching solution, the exposed titanium film 27aa is nitrided before the processing using the etching solution. Do the processing,
It is necessary to form the titanium nitride film 35aa.

As shown in FIG. 26, the structure of the contact 8 shown in FIG. 24 can be adapted to the structure of the via hole 11. In FIG. 26, reference numerals 9b and 11
aa, 12b, and 35bb indicate titanium nitride films, 27bb indicates a titanium film, and 11bb indicates a tungsten film.

It is to be noted that an example is shown in which titanium nitride films 9b and 12b as antireflection films are formed on the upper surfaces of the first metal wiring 9 and the second metal wiring 12. The titanium film 27bb and the titanium nitride film 11aa constituting the via hole 11 are formed to protrude outside the via hole 11 above the interlayer insulating film 10.
Before patterning the second metal wiring 12 and removing the resist or polymer with a strong alkaline etchant, the titanium film 27bb soluble in an alkaline solution is selectively nitrided to form a titanium nitride film 35bb. And alkali resistance.

Therefore, the titanium film 27bb and the tungsten film 11bb are not eluted even if the resist or polymer is removed using a strong alkaline etching solution, and the via hole 11 and the second metal wiring 1 are not dissolved.
2 can be obtained in a good connection state.

Also, the contact 8 and the first metal wiring 9,
Alternatively, even when a misalignment occurs between the via hole 11 and the second metal wiring 12, the exposed alkali-soluble portion may be removed after the patterning of the first and second metal wirings 9 and 12. Since the material can be selectively nitrided to be an alkali-resistant substance, elution of the conductive substance by the strong alkaline etching solution can be suppressed, and a good connection state can be finally obtained.

The contact 8 of the eighth embodiment
It is needless to say that the structure of the via hole 11 (or the contact 8) described in the first to seventh embodiments can be combined with the structure of the via hole 11 and used in one semiconductor device.

Embodiment 9 FIG. Next, a ninth embodiment of the present invention will be described. FIG. 27 shows a semiconductor device according to the ninth embodiment. The feature of this semiconductor device is that the first metal wiring 9 connected to the upper part of the contact 8 has a lower surface than the first metal wiring 9 does. The point is that an alkali-resistant titanium nitride film 37a having a large formation area is formed. This titanium nitride film 3
By making 7 a larger than the horizontal dimension of contact 8, the cover margin between contact 8 and first metal wiring 9 is improved.

In FIG. 27, reference numeral 38a denotes a side wall made of an insulating film attached to a side cross section of the first metal wiring 9, and the same reference numerals as those already described for the description are the same. , Or corresponding parts.

Next, a method of manufacturing the semiconductor device shown in FIG. 27 will be described with reference to FIG. First, as shown in FIG. 28A, the contact 8 is formed according to the manufacturing method of FIGS. 18A and 18B of the sixth embodiment.

Thereafter, as shown in FIG. 28B, a 700 nm thick titanium nitride film 37a and a 4000 nm thick aluminum are formed by sputtering.
A metal film 9a to be the first metal wiring 9 and a titanium nitride film 9b having a thickness of 600 順次 are sequentially laminated, and then a silane-based oxide film 3 having a thickness of 3000 に よ っ て is formed by a plasma CVD method.
9a is laminated. Further, a resist pattern 17 having a shape corresponding to the first metal wiring 9 is patterned by photolithography.

Next, as shown in FIG. 28C, anisotropic etching is performed on the silane-based oxide film 39a using the resist pattern 17 as an etching mask and the titanium nitride film 9b as an etching stopper. An etching mask 39 made of an oxide film is obtained. At this time, the polymer 36 is attached to the cross section formed by the anisotropic etching.

As shown in FIG. 28D, the resist pattern 17 is removed by oxygen plasma ashing, and subsequently, as a strong alkaline etching solution, 2-2 aminoethoxyethanol (60%) and hydroxylamine (18%) , Water (17%), catechol (5%): a strong alkali (pH = 12), a removal treatment at 60 ° C. for 30 minutes to peel and remove the polymer 36. The removal of the resist pattern 17 and the polymer 36 can be performed in a single removal step using a strong alkaline etching solution.

Next, as shown in FIG. 28E, anisotropic etching is performed on the titanium nitride film 9b using the etching mask 39, and subsequently, the metal film is formed using the titanium nitride film 37a as an etching stopper. Anisotropic etching is performed on the first metal wiring 9a.
Get. The polymer 36 generated as a foreign substance by the anisotropic etching at this time is removed by oxygen plasma ashing and treatment with a strong alkaline etchant in a later step.

Thereafter, as shown in FIG. 28F, a silane-based oxide film is laminated on the entire surface, and then anisotropically etching is performed on the entire surface to thereby form the titanium nitride film 9b and the first metal wiring 9 side. A sidewall 38a made of a silane-based oxide film is formed on the cross section. The etching mask 39 made of a silane-based oxide film is also removed by this anisotropic etching. Next, anisotropic etching is performed on the titanium nitride film 37a using the titanium nitride film 9b and the side wall 38a as an etching mask, and the first metal wiring 9 and the bottom surface of the side wall 38a formed therearound are etched. A titanium nitride film 37a that adheres and completely covers the top of the contact 8 is obtained. Further, the semiconductor device shown in FIG. 27 can be obtained through a process of manufacturing the interlayer insulating film 10 and the like.

In the semiconductor device formed as described above, even if the first metal wiring 9 and the contact 8 are formed so as to have a misalignment, the first metal wiring 9 and the contact 8 may not overlap each other. The connection between the two is ensured by patterning the titanium nitride film 37a interposed therebetween so as to have a larger area than the first metal wiring 9. Also, the titanium nitride film 37a
Since the upper portion of the contact 8 is covered by this to prevent the contact 8 from being exposed to an etchant or the like, it goes without saying that there is no elution of the conductive material constituting the contact 8. Also, even when the first metal wiring 9 is formed to have a small size due to CD loss, good connection with the contact 8 is similarly enabled.

As shown in FIG. 29, the shapes of the first metal wiring 9 and the titanium nitride films 9b and 37a and the side walls 38a formed on the upper and lower layers of the first metal wiring 9 shown in FIG.
It can also be used as a wiring structure formed on the via hole 11. The via hole 11 can be formed by a tungsten film 11b and a titanium nitride film 11a surrounding the periphery of the tungsten film 11. In FIG. 29, reference numeral 37b denotes a titanium nitride film, 38b denotes a side wall, and the same reference numerals as those already used for the description denote the same or corresponding parts.

As shown in FIG. 29, between the second metal wiring 12 and the via hole 11, the second metal wiring 12
Formed between the second metal wiring 12 and the via hole 11 by forming the titanium nitride film 37b larger than the formation area of the second metal wiring 12 and extending horizontally from both side surfaces of the second metal wiring 12. Even if the superposition is displaced, it is possible to obtain a good connection between the two. Further, since the via hole 11 is not exposed to the strong alkaline etching solution, the conductive material constituting the via hole 11 is not eluted, and a good connection state between the via hole 11 and the second metal wiring 12 can be obtained. It is possible.

By using the technique of the ninth embodiment, the contact 8 and the first metal wiring 9 connected thereto are connected.
And a titanium nitride film 37a are formed, and the via hole 11 and the second metal wiring 12 connected to the via hole 11 are formed by using any of the techniques described in the first to eighth embodiments.
It is needless to say that a combination such as forming

[0171]

The effects of each claim of the present invention will be described below. According to the semiconductor device of the first aspect of the present invention, the horizontal dimension at the upper portion of the connection portion of the alkali-resistant conductive film is equal to or larger than the size corresponding to the misalignment caused when forming the borderless wiring, and By forming the film so as to have a film thickness smaller than 最大 of the maximum dimension in the direction, when the borderless wiring is formed with a misalignment or a CD loss, the exposed region above the connection portion is resistant to the resistance. Since the alkaline conductive film is formed, the conductive material forming the connecting portion does not elute even when exposed to a strong alkaline etching solution, and a good connection state between the borderless wiring and the connecting portion can be obtained. It is possible.

Further, according to the semiconductor device of the second aspect of the present invention, the horizontal thickness of the alkali-resistant conductive film on the connection portion is set to a value of not less than 1000 ° and less than 1500 °, so that a borderless micron device can be used. The exposed surface of the connection portion can be made of an alkali-resistant substance due to the misalignment (a size of 1000 ° or less) generated between the wiring and the connection portion. Therefore, the conductive material constituting the connection portion does not elute even when exposed to the strong alkaline etchant, and a good connection state between the borderless wiring and the connection portion can be obtained.

According to the semiconductor device of the third aspect of the present invention, as the alkali-resistant conductive film, a titanium nitride film or a multilayer structure of a titanium nitride film and a titanium tungsten film can be used. Even when the connection between the connection portion and the borderless wiring is misaligned, the formation of the alkali-resistant conductive film made of these films eliminates the elution of the conductive substance by the strong alkaline etching solution, and the borderless wiring is eliminated. It is possible to obtain a good connection state between the and the connection part.

Further, according to the semiconductor device of the fourth aspect of the present invention, the upper surface of the connection portion is covered with a nitride film or a titanium compound, so that the entire upper surface of the connection portion is formed as an alkali-resistant conductive film, and is formed on the upper portion. Even when the upper wiring is formed with a misalignment, the elution of the conductive material forming the connecting portion can be prevented, and a good connection between the upper wiring and the connecting portion can be obtained.

According to the semiconductor device of the fifth aspect of the present invention, the alkali-resistant conductive film is formed in a region where the connection portion and the upper wiring do not overlap, that is, on the connection portion corresponding to a misalignment portion. By doing so, the conductive material constituting the connection portion does not elute even when exposed to a strong alkaline etchant, and a good connection state between the upper wiring and the connection portion can be obtained.

Further, according to the semiconductor device of the sixth aspect of the present invention, when the upper wiring has a multi-layer structure, the cross section of the lowermost adhesive layer is made of an alkali-resistant substance, so that it can be used in an alkaline etching solution. To be resistant to
Even when exposed to a strong alkaline etchant, the conductive material constituting the connection portion is not eluted, and a good connection between the upper wiring and the connection portion can be obtained.

According to the semiconductor device of the seventh aspect of the present invention, the cross section of the conductive film sandwiched between the bottom surface of the upper wiring and the surface of the interlayer insulating film and adhered to the side wall of the connection portion is formed. By forming a nitride film, which is an alkali-resistant substance, the conductive material constituting the connection portion does not elute even when exposed to a strong alkaline etching solution, and a good connection state can be obtained.

Further, according to the semiconductor device of the present invention, the alkali-resistant conductive film is sandwiched between the bottom surface of the upper wiring and the surface of the interlayer insulating film and adhered to the side wall of the connection portion. In the case of forming a laminated structure of the film and the alkali-soluble conductive film, the exposed section of the alkali-soluble conductive film is nitrided to form an alkali-resistant nitride film, so that the connection portion is formed even when exposed to a strong alkaline etching solution. It is possible to obtain a good connection state between the upper wiring and the connection portion without eluting the conductive material.

Further, according to the semiconductor device of the ninth aspect of the present invention, the upper wiring is formed in a multilayer structure of a metal film and an alkali-resistant conductive film formed on the bottom surface of a sidewall attached to a cross section of the metal film. By making the area occupied by the alkali-resistant conductive film larger than the area occupied by the metal film, a margin for connection with the connection portion is provided, and even when the metal film of the upper wiring and the connection portion are misaligned. The state where the upper surface of the connection portion is not exposed can be obtained. Therefore, when the upper wiring is formed, the conductive material constituting the connecting portion is not eluted even when exposed to a strong alkaline etching solution, and a good connection between the upper wiring and the connecting portion can be obtained.

Further, according to the semiconductor device of the tenth aspect of the present invention, the connection portion having the structure corresponding to the first, second, fourth to seventh and ninth aspects can be used as a contact hole or a via hole. It is possible.

According to the semiconductor device of the present invention, any one of a titanium nitride film, a titanium tungsten film, and a tungsten nitride film is used as the alkali-resistant conductive film having the structure corresponding to the fourth to ninth aspects. By using a titanium nitride film as the alkali-resistant nitride film, it is possible to obtain a semiconductor device in which a conductive material forming a contact or a via hole is not eluted even when exposed to a strongly alkaline etching solution.

According to the method of manufacturing a semiconductor device according to the twelfth aspect of the present invention, the horizontal dimension of the upper portion of the connection portion of the alkali-resistant conductive film is equal to or more than the dimension corresponding to the misalignment caused when forming the borderless wiring. And
By forming the connection portion so as to have a film thickness smaller than 最大 of the maximum horizontal dimension, even if a borderless wiring is formed with a misalignment in the subsequent process, the upper portion of the connection portion is formed. Since the exposed region is in a state where the alkali-resistant conductive film is formed, the conductive material constituting the connection portion does not elute even when exposed to a strong alkaline etching solution, and a good connection between the borderless wiring and the connection portion is obtained. It is possible to get the status.

Further, according to the method of manufacturing a semiconductor device according to the thirteenth aspect of the present invention, the thickness of the alkali-resistant conductive film on the connection portion in the horizontal direction is not less than 1000 ° and not more than 1500 °.
Since the process includes the step of reducing the size to less than Å, the connection portion exposed at the time of forming the wiring is alkali-resistant due to the misalignment (size of 1000 Å or less) generated between the borderless wiring and the connection portion in the sub-quarter micron device. It can be a substance, and even if it is exposed to a strong alkaline etching solution, the conductive material constituting the connection part does not elute,
It is possible to obtain a good connection state between the borderless wiring and the connection part.

According to the method of manufacturing a semiconductor device according to the fourteenth aspect of the present invention, the upper surface of the connection portion is covered with a nitride film or a titanium compound, so that the entire upper surface of the connection portion is made of an alkali-resistant conductive film. Even when the upper wiring to be formed is formed with a misalignment, the elution of the conductive material constituting the connection portion can be prevented, and a good connection between the upper wiring and the connection portion can be obtained.

Further, according to the method of manufacturing a semiconductor device according to the fifteenth aspect of the present invention, a region where the connection portion and the upper wiring do not overlap, that is, an upper portion of the connection portion corresponding to a misalignment portion is selectively provided. By forming the alkali-resistant conductive film, the conductive material constituting the connection portion is not eluted even if a strong alkali etching treatment is performed after the formation of the upper layer wiring, so that a good connection state between the upper layer wiring and the connection portion can be obtained. It is possible to get.

According to the method of manufacturing a semiconductor device of the present invention, the upper wiring has a multilayer structure,
By providing a manufacturing process equivalent to making the cross section of the lowermost adhesive layer an alkali-resistant substance, it has resistance to an alkaline etchant and can be connected even when exposed to a strong alkaline etchant. It is possible to obtain a good connection state between the upper wiring and the connection portion without eluting the conductive material constituting the portion.

Further, according to the method of manufacturing a semiconductor device of the seventeenth aspect of the present invention, the conductive film sandwiched between the bottom surface of the upper wiring and the surface of the interlayer insulating film and adhered to the side wall of the connection portion is formed. A manufacturing process equivalent to forming a nitride film, which is an alkali-resistant substance, in the cross-section, or a laminated structure of an alkali-resistant conductive film and an alkali-soluble conductive film as a conductive film adhered to the side wall of the connection portion. Is provided with a manufacturing process equivalent to nitriding the exposed cross section of the alkali-soluble conductive film to form an alkali-resistant nitride film, so that the conductive material constituting the connection portion even when exposed to a strong alkaline etching solution , And a good connection state between the upper wiring and the connection portion can be obtained.

According to the method of manufacturing a semiconductor device according to the eighteenth aspect of the present invention, the upper wiring has a multilayer structure of a metal film and an alkali-resistant conductive film formed on the bottom surface of a sidewall attached to a cross section thereof. Since a manufacturing process corresponding to forming the area occupied by the alkali-resistant conductive film larger than the area occupied by the metal film is provided, a margin of connection with the connection portion is provided, and the connection with the metal film of the upper wiring is performed. The upper surface of the connection portion can be kept in a state where the upper surface of the connection portion is not exposed even when the portion is misaligned. Therefore, when the upper wiring is formed,
Even when exposed to a strong alkaline etchant, the conductive material constituting the connection portion is not eluted, and a good connection between the upper wiring and the connection portion can be obtained.

Further, according to the method of manufacturing a semiconductor device according to the nineteenth aspect of the present invention, one of the connection portions obtained by the manufacturing method corresponding to the eleventh and thirteenth to seventeenth aspects can be used as a contact hole. A semiconductor device can be formed by using a via hole.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a semiconductor device according to a first embodiment of the present invention;

FIG. 2 is a fragmentary cross-sectional view of the semiconductor device according to Embodiment 1 of the present invention;

FIG. 3 is a diagram showing a manufacturing flow of the semiconductor device according to the first embodiment of the present invention;

FIG. 4 is a fragmentary cross-sectional view of the semiconductor device according to the first embodiment of the present invention;

FIG. 5 is a fragmentary cross-sectional view of a semiconductor device according to a second embodiment of the present invention;

FIG. 6 is a view illustrating a manufacturing flow of the semiconductor device according to the second embodiment of the present invention;

FIG. 7 is a fragmentary cross-sectional view of a semiconductor device according to a second embodiment of the present invention;

FIG. 8 is a fragmentary cross-sectional view of a semiconductor device according to Embodiment 3 of the present invention;

FIG. 9 is a diagram illustrating a manufacturing flow of the semiconductor device according to the third embodiment of the present invention;

FIG. 10 is a fragmentary cross-sectional view of a semiconductor device according to a third embodiment of the present invention;

FIG. 11 is a fragmentary cross-sectional view of a semiconductor device according to a fourth embodiment of the present invention;

FIG. 12 is a view illustrating a manufacturing flow of the semiconductor device according to Embodiment 4 of the present invention;

FIG. 13 is a fragmentary cross-sectional view of a semiconductor device according to a fourth embodiment of the present invention;

FIG. 14 is a fragmentary cross-sectional view of a semiconductor device according to a fifth embodiment of the present invention;

FIG. 15 is a view illustrating a manufacturing flow of the semiconductor device according to the fifth embodiment of the present invention;

FIG. 16 is a fragmentary cross-sectional view of a semiconductor device according to a fifth embodiment of the present invention;

FIG. 17 is a fragmentary cross-sectional view of a semiconductor device according to Embodiment 6 of the present invention;

FIG. 18 is a view illustrating a manufacturing flow of the semiconductor device according to Embodiment 6 of the present invention;

FIG. 19 is a fragmentary cross-sectional view of a semiconductor device according to Embodiment 6 of the present invention;

FIG. 20 is a fragmentary cross-sectional view of a semiconductor device according to Embodiment 7 of the present invention;

FIG. 21 is a view illustrating a manufacturing flow of the semiconductor device according to Embodiment 7 of the present invention;

FIG. 22 is a fragmentary cross-sectional view of a semiconductor device according to a seventh embodiment of the present invention;

FIG. 23 is an essential part cross sectional view of the semiconductor device of Embodiment 7 of the present invention;

FIG. 24 is a fragmentary cross-sectional view of a semiconductor device according to an eighth embodiment of the present invention;

FIG. 25 is a view illustrating a manufacturing flow of the semiconductor device according to the eighth embodiment of the present invention;

FIG. 26 is a fragmentary cross-sectional view of a semiconductor device according to an eighth embodiment of the present invention;

FIG. 27 is a fragmentary cross-sectional view of a semiconductor device according to a ninth embodiment of the present invention;

FIG. 28 is a view illustrating a manufacturing flow of the semiconductor device according to Embodiment 9 of the present invention;

FIG. 29 is a fragmentary cross-sectional view of a semiconductor device according to a ninth embodiment of the present invention;

FIG. 30 is a diagram showing a semiconductor device according to a conventional technique.

FIG. 31 is a view showing a flow of manufacturing a semiconductor device according to a conventional technique.

FIG. 32 is a plan view for explaining a conventional technique.

FIG. 33 is a plan view for explaining a conventional technique.

FIG. 34 is a view showing a semiconductor device according to a conventional technique.

FIG. 35 is a view showing a semiconductor device according to a conventional technique.

[Explanation of symbols]

1. Semiconductor substrate 2. LOCOS oxide film 3. 3. Impurity region 4. Gate oxide film Gate electrode 5a. Polysilicon film 5b. Tungsten silicide film 6, 38a, 38b. Side wall 7,10. 7. Interlayer insulating film Contact 8a, 8aa, 9b, 11a, 11aa, 29, 29
a, 32, 35a, 35aa, 35bb, 37a, 37
b. Titanium nitride film 8b, 8bb, 11b, 11bb, 19. Tungsten film 8c, 11c, 25, 26, 28, 31, 33, 34,
28a. Tungsten nitride film 8d, 11d, 21, 23. 8. Titanium tungsten film First metal wiring 9a. Metal film 11. Via hole 12. Second metal wiring 13. Passivation film 14. 14. Titanium silicide film Contact holes 16, 20, 22, 22a, 24, 27, 27aa, 2
7bb, 30, 35. Titanium film 17. Resist pattern 18. Titanium aluminum alloy film 36. Polymer 39. Silane-based oxide film 39a. Etching mask

Claims (19)

[Claims] 1. A semiconductor substrate, a conductive region formed on a surface or an upper portion of the semiconductor substrate, and a conductive material formed from an upper surface of at least an interlayer insulating film laminated on the conductive region to a surface of the conductive region. A connection portion, including a borderless wiring formed on a surface of the interlayer insulating film in contact with the connection portion, wherein the connection portion includes an alkali-resistant conductive film, and at least the alkali-resistant conductive material surrounding a side wall of the connection portion. The film thickness of the film in the horizontal direction above the connection portion is a value equal to or larger than a size corresponding to a misalignment generated when forming the borderless wiring, and is smaller than 1/2 of a maximum horizontal size of the connection portion. A semiconductor device formed to have a thickness. 2. The film thickness of the alkali-resistant conductive film in the horizontal direction above the connection portion is 1000 ° or more and 1500 ° or more.
2. The semiconductor device according to claim 1, wherein the size of the semiconductor device is less than. 3. The semiconductor device according to claim 1, wherein the alkali-resistant conductive film has a titanium nitride film or a multilayer structure of a titanium nitride film and a titanium tungsten film. 4. A semiconductor substrate, a conductive region formed on or above the semiconductor substrate, and at least a conductive material formed from the upper surface of an interlayer insulating film laminated on the conductive region to the surface of the conductive region. A connection portion, including an upper layer wiring formed on the surface of the interlayer insulating film in contact with the connection portion, wherein the connection portion includes an alkali-resistant conductive film, and the alkali-resistant conductive film covers an upper surface of the connection portion. A nitrided conductive film or a conductive titanium compound in which the upper surface of the connection portion is combined with a titanium film. The connection portion and the upper wiring are electrically connected via the nitrided conductive film or the conductive titanium compound. A semiconductor device characterized by being performed. 5. A semiconductor substrate, a conductive region formed on a surface or an upper portion of the semiconductor substrate, and a conductive material formed from at least an upper surface of an interlayer insulating film laminated on the conductive region to a surface of the conductive region. A connection portion, which includes an upper layer wiring formed on the surface of the interlayer insulating film in contact with the connection portion, wherein the connection portion includes an alkali-resistant conductive film, and the alkali-resistant conductive film is formed on an upper surface of the connection portion. A semiconductor device selectively formed in a region not overlapping with the upper layer wiring. 6. The upper wiring according to claim 5, wherein the upper wiring has a multilayer structure, has an adhesion layer in the lowermost layer, and has an alkali-resistant nitride film formed at least in a cross section of the adhesion layer. Semiconductor device. 7. A conductive material formed from a top surface of a semiconductor substrate, a conductive region formed on a surface or an upper portion of the semiconductor substrate, at least an interlayer insulating film laminated on the conductive region, to a surface of the conductive region. A connection portion, an upper wiring formed in contact with the connection portion and formed on the surface of the interlayer insulating film, sandwiched between at least a bottom surface of the upper wiring and the surface of the interlayer insulating film, and adhered to a side wall of the connection portion. A semiconductor device including a conductive film formed on the substrate, wherein an alkali-resistant nitride film is formed in a cross-sectional portion of the conductive film along a cross section of the upper wiring. 8. The conductive film has a laminated structure of at least an alkali-resistant conductive film and an alkali-soluble conductive film, and the nitride film is formed by nitriding a cross section of the alkali-soluble conductive film. Item 8. The semiconductor device according to item 7. 9. A semiconductor substrate, a conductive region formed on a surface or an upper portion of the semiconductor substrate, and a conductive material formed from an upper surface of at least an interlayer insulating film laminated on the conductive region to a surface of the conductive region. A connecting portion, which includes an upper layer wiring formed on the surface of the interlayer insulating film in contact with the connecting portion, wherein the upper layer wiring has a multilayer structure including a metal film and an alkali-resistant conductive film attached to the bottom surface of the metal film. A semiconductor device, wherein the alkali-resistant conductive film is formed under a bottom surface of the metal film and under a bottom surface of a sidewall attached to a side cross section of the metal film. 10. A contact hole for connecting an impurity region formed in a semiconductor substrate to a first metal wiring, or a via hole for connecting the first metal wiring to a second metal wiring. The semiconductor device according to claim 1, wherein: 11. The alkali-resistant conductive film is made of any one of a titanium nitride film, a titanium tungsten film and a tungsten nitride film, and the alkali-resistant nitride film is a titanium nitride film. 4 ~
10. The semiconductor device according to claim 9. 12. A step of laminating an interlayer insulating film on a surface of a semiconductor substrate or a surface of a conductive region formed on an upper portion thereof, and a step of forming an opening reaching the surface of the conductive region from the surface of the interlayer insulating film. A step of stacking an alkali-resistant conductive film on the surface of the interlayer insulating film including the side wall of the opening, a step of stacking a tungsten film on the surface of the alkali-resistant conductive film, and embedding the opening, Etching back to the surface to obtain a connection portion including the alkali-resistant conductive film and the tungsten film buried in the opening, and resisting the borderless wiring on the interlayer insulating film so as to be in contact with the connection portion; Forming using a pattern, using a strong alkaline etchant to remove the resist pattern or foreign matter generated when removing the resist pattern The thickness of the alkali-resistant conductive film in the horizontal direction on the extending surface of the surface of the interlayer insulating film is equal to or greater than the displacement of the connection portion and the borderless wiring. A method of manufacturing the semiconductor device, wherein the film thickness is less than half the maximum diameter of the opening. 13. The horizontal thickness of the extension surface of the surface of the interlayer insulating film of the alkali-resistant conductive film is not less than 1000 ° and 1
2. The method according to claim 1, wherein the size is less than 500 degrees.
2. The method for manufacturing a semiconductor device according to claim 1. 14. A step of laminating an interlayer insulating film on a surface of a semiconductor substrate or a surface of a conductive region formed on an upper portion thereof, and a step of forming an opening reaching the surface of the conductive region from the surface of the interlayer insulating film. Laminating an adhesion layer on the surface of the interlayer insulating film including the side wall of the opening, laminating a tungsten film on the surface of the adhesion layer and embedding the opening, etching to the surface of the interlayer insulating film Performing a backing process to obtain a connection portion including the adhesion layer and the tungsten film buried in the opening, a process of forming an upper surface of the connection portion into an alkali-resistant conductive film, and forming the connection portion on the interlayer insulating film. Forming an upper layer wiring using a resist pattern in a state of contacting with the resist pattern, and removing the resist pattern or foreign matter generated at the time of removing the resist pattern with a strong alkaline etching solution. A method of manufacturing a semiconductor device, characterized by including a step of removing the substrate by using the method described above, wherein the alkali-resistant conductive film is formed by nitriding or titanium compounding the upper surface of the connection portion. 15. A step of laminating an interlayer insulating film on a surface of a semiconductor substrate or a surface of a conductive region formed on an upper portion, and a step of forming an opening reaching the surface of the conductive region from the surface of the interlayer insulating film. Laminating an adhesion layer on the surface of the interlayer insulating film including the side wall of the opening, laminating a tungsten film on the surface of the adhesion layer and embedding the opening, etching to the surface of the interlayer insulating film Performing a backing process to obtain a connection portion including the adhesion layer and the tungsten film embedded in the opening, and forming an upper layer wiring on the interlayer insulating film in contact with the connection portion using a resist pattern. A step of nitriding an exposed upper surface of the connection part located in a region where the upper wiring and the connection part do not overlap, the resist pattern or the resist pattern A method for manufacturing a semiconductor device, comprising a step of removing foreign matter generated at the time of removal using a strong alkaline etching solution, and forming an alkali-resistant conductive film by nitriding an upper surface of the connection portion. 16. An upper wiring is formed so as to have a multilayer structure including an adhesion layer and a metal film, and when the adhesion layer is made of an alkali-soluble substance, the upper wiring is located in a region where the connection portion does not overlap with the connection portion. 15. The method of manufacturing a semiconductor device according to claim 14, wherein in the step of nitriding the exposed upper surface of the connection portion, the exposed portion of the adhesion layer is simultaneously nitrided. 17. A step of laminating an interlayer insulating film on a surface of a semiconductor substrate or a surface of a conductive region formed on an upper portion thereof, and a step of forming an opening reaching the surface of the conductive region from the surface of the interlayer insulating film. Laminating an adhesion layer on the surface of the interlayer insulating film including the side wall of the opening, laminating a tungsten film on the surface of the adhesion layer, etching back the tungsten film using the adhesion layer as an etching mask, A step of obtaining a connection portion made of the adhesion layer and the tungsten film in the opening; a step of laminating a metal film on the surface of the connection portion and the adhesion layer; a resist pattern on the metal film at a position overlapping the connection portion Forming an upper layer wiring by sequentially anisotropically etching the metal film and the adhesion layer using the resist pattern as an etching mask. Nitriding the exposed cross section of the connection portion and the upper wiring, and removing the resist pattern or foreign matter generated at the time of removing the resist pattern using a strong alkaline etchant, wherein the connection portion and the upper wiring are removed. A method of manufacturing a semiconductor device, wherein the exposed cross-section is completely covered with an alkali-resistant conductive film by nitriding the exposed cross-section. 18. A step of laminating an interlayer insulating film on a surface of a semiconductor substrate or a surface of a conductive region formed on an upper portion thereof, and a step of forming an opening extending from the surface of the interlayer insulating film to the surface of the conductive region. Laminating a first adhesion layer on the surface of the interlayer insulating film including the side wall of the opening, laminating a tungsten film on the surface of the first adhesion layer, and embedding the opening, Performing a etch back to the surface of the film to obtain a connection including the first adhesion layer buried in the opening and the tungsten film; resisting a state on the interlayer insulating film and in contact with the connection; A step of sequentially laminating a second adhesion layer, which is an alkaline conductive film, and a metal film; a step of patterning the metal film into a shape of an upper wiring overlapping the connection portion by using an etching mask; Removing a foreign matter generated at the time of removing the etching mask or the etching mask by using a strong alkaline etching solution, forming a sidewall in a side cross section of the upper wiring, and removing the foreign matter located below the sidewall and the upper wiring. A method of manufacturing a semiconductor device, comprising a step of leaving the adhesion layer and removing the others. 19. A contact hole for connecting an impurity region formed in a semiconductor substrate to a first metal wiring, or a via hole for connecting the first metal wiring to a second metal wiring. The method for manufacturing a semiconductor device according to claim 11, wherein the semiconductor device is formed as: