JP3250518B2 - Semiconductor device and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device and a method of manufacturing a semiconductor device, and more particularly, to a method of manufacturing a semiconductor device having an insulating interlayer formed of a material having a low dielectric constant. The present invention relates to a semiconductor device in which the insulating interlayer film is prevented from deteriorating during a peeling process of a photoresist layer after an etching process at the time of formation, and a method of manufacturing the same.

[0002]

2. Description of the Related Art In recent years, demands for high-speed LSI signal processing have been increasing year by year. The signal processing speed of the LSI is mainly determined by the operation speed of the transistor itself and the magnitude of the signal propagation delay time in the wiring. Conventionally, the operating speed of a transistor, which has had a great influence, has been improved by reducing the size of the transistor. However, in an LSI having a design rule of less than 0.25 μm, the influence of the latter wiring on signal propagation delay is beginning to appear significantly.
In particular, the effect is great in an LSI device having a multilayer wiring layer having more than four wiring layers.

Therefore, as a method of improving the signal propagation delay of the wiring, an interlayer insulating film having a low relative dielectric constant has been studied instead of the conventional interlayer insulating film made of a silicon oxide film. Among them, HSQ and organic SOG, which can obtain a relative dielectric constant of about 3.0, are highly complete and are expected to be mass-produced. First, HSQ will be described. HSQ is a resin in which a part of the Si—O bond of the silicon oxide film is replaced with a Si—H bond, and is used as an interlayer insulating film by being applied on a substrate and baked under heating.

Since most of HSQ is formed from Si—O bonds similar to a conventional silicon oxide film, HSQ has heat resistance at a low dielectric constant up to about 500 ° C. However, when the HSQ film is applied to the interlayer insulating film and various patterns are formed by a normal lithography method and an etching method, the HSQ film is deteriorated in a step of removing the photoresist used for the patterning, and a plug such as tungsten is formed. In the process, problems such as poisoned vias where vias are not buried occur.

[0005] This is because HSQ is used in the photoresist stripping step.
This is due to an increase in the water component in the film. In the photoresist stripping step, usually, most of the photoresist is stripped by oxygen plasma treatment, and then the photoresist stripping residue and etching residue are removed with a wet stripper. However, when the oxygen plasma treatment is performed, the Si—H bonds in the HSQ film are broken and easily converted to Si—OH bonds. Further, when a wet stripping solution containing an amine group such as hydroxylamine or ethanolamine is used in the subsequent processing step using a wet stripping solution, HSQ can be used similarly to the oxygen plasma treatment.
Almost all Si-H bonds in the film are broken, and Si-OH bonds are formed.

When a wet-stripping liquid containing ammonium fluoride is used, the HSQ film itself is etched together with the deterioration of the HSQ film, and the shape of the via hole and the like becomes a bowing shape. Cause problems. In addition, poor filling of metal such as tungsten is caused. Next, organic SOG is S
i-CH ₃ bond film weak Si-CH ₃ bonds to ashing by oxygen plasma as in the HSQ having would easily become Si-OH. Also, it is similar to HSQ in that it is relatively porous compared to an oxide film and therefore has no etching resistance to ammonium fluoride.

FIG. 6 shows an example of a semiconductor device manufactured by a conventional method, and its problems will be described in detail. Here, an example using HSQ is shown. That is, the Al on the substrate 1
A silicon oxide film 4 is formed as a first wiring 3 and a first interlayer insulating film, and then an HSQ film as a coating film is formed as a second interlayer insulating film 5. Thereafter, an example of a semiconductor device 10 in which a silicon oxide film is formed as a third interlayer insulating film 6 by using a plasma CVD method or the like will be described.

In the conventional example, a pattern is formed by well-known photolithography and etching, and then, in a step of removing the photoresist with oxygen plasma, a Si—OH bond is formed in the HSQ film 5 and the HSQ is formed.
The film quality of SQ5 is deteriorated (FIG. 6A). Further, when a treatment with a wet stripping solution containing an amine group or a wet stripping solution containing ammonium fluoride is performed to remove the photoresist stripping residue and the etching residue, Si—OH bonds are formed in the HSQ film 5. You.

In particular, when a wet stripping solution containing ammonium fluoride is used, the HSQ film 5 is etched to have a bowing shape as shown in FIG. This is because ammonium fluoride etches the silicon oxide film, and in particular, the HSQ film has a much higher etching rate than a film formed by a CVD method or the like.

[0010] Such a bowing shape not only causes a leak or short circuit between vias, but also causes a failure in embedding a metal such as tungsten. In addition, the formation of Si—OH in the HSQ film 5 increases the relative dielectric constant of the HSQ film. Therefore, there is a problem in manufacturing a semiconductor device by lowering the relative dielectric constant. Incidentally, Japanese Patent Application Laid-Open
Japanese Patent Application Laid-Open No. 192137 discloses a technical idea for solving the problem that the insulating interlayer film is deteriorated when a photoresist layer is peeled off when forming a via hole in the insulating interlayer film using the SOG method. Not.

Japanese Patent Application Laid-Open No. 1-1191450 discloses that
After forming an opening in the insulating interlayer film by etching,
A technique for preventing a change in the resistance value of the metal electrode portion by performing a treatment with a choline solution and an oxygen plasma treatment on the opening is disclosed.
There is no disclosure of a technique for preventing deterioration of the insulating interlayer when Q and organic SOG are used for the insulating interlayer.

On the other hand, Japanese Patent Application Laid-Open Nos. Hei 4-262431 and Hei 4-263428 disclose that a contact hole is formed in an insulating interlayer film after the contact hole is formed in order to improve the ashing resistance of the insulating interlayer film. A method of performing an inorganic treatment by applying oxygen plasma to the material is shown, but HSQ and organic S which are low dielectric constant materials are
There is no disclosure of a technique for preventing deterioration of the insulating interlayer film when OG is used for the insulating interlayer film.

Japanese Patent Application Laid-Open No. 5-114656 discloses that
Disclosed is a technique for plasma-treating the inside of the via hole for the purpose of improving the contact property of the metal electrode in the via hole provided in the insulating interlayer film and suppressing outgassing generated from the side wall of the via hole. HSQ and organic S which are low dielectric constant materials
There is no disclosure of a technique for preventing deterioration of the insulating interlayer film when OG is used for the insulating interlayer film.

[0014]

SUMMARY OF THE INVENTION It is therefore an object of the present invention to solve the above-mentioned problems. That is, the HSQ film and the organic SOG are deteriorated by the wet stripping solution used when the photoresist used for forming the various patterns is removed by the oxygen plasma treatment and when the etching residue is removed, and the films themselves are not etched. By doing so, a technique for manufacturing a semiconductor device having an insulating interlayer film having a low relative dielectric constant is provided.

[0015]

The present invention employs the following technical configuration to achieve the above object. That is, as a first aspect according to the present invention, a material having a low dielectric constant formed on a substrate is used.
In the opening provided between the configured interlayer insulating films
In addition to the wiring part whose one end is in contact with the substrate and the wiring part
Vias consisting of metal layers placed on the edges
Is formed in the semiconductor device, wherein the opening is
Inner wall of the interlayer insulating film in contact with at least the via portion
A semiconductor device formed on the surface by hydrogen plasma ; and a second aspect according to the present invention is a semiconductor device formed on a substrate.
Made of a material having a low relative dielectric constant
In a groove having an opening provided between the insulating films,
A wiring part whose one end is in contact with the substrate is embedded,
And, of the inner wall portion in contact with the wiring portion in the groove portion,
A protective film made of hydrogen plasma is formed on the surface
Is a semiconductor device are.

Further, according to a third aspect of the present invention,
Composed of low dielectric constant material formed on substrate
Semiconductor with a wiring part between the interlayer insulating films
A method for manufacturing a semiconductor device, the method comprising:
Is a method for forming an appropriate wiring portion on the semiconductor substrate.
Process, a low relative dielectric constant on the semiconductor substrate having the wiring portion
Second process for forming an interlayer insulating film made of the material to be presented
A photoresist is applied on the interlayer insulating film;
Mask the predetermined pattern opening provided in the photoresist layer
Etching the interlayer insulating film to remove the wiring
A third step of forming a groove-shaped opening reaching
Inner wall surface of the groove-shaped opening in the semiconductor substrate
The fourth step of forming a protective film with hydrogen plasma on the
A fifth step of removing the photoresist layer.
And it has a manufacturing method of a semiconductor device, and, as a fourth aspect according to the present invention, an interlayer insulation are formed on a substrate
In a method of manufacturing a semiconductor device in which a wiring portion is provided between films,
The method for manufacturing a semiconductor device includes the steps of:
An interlayer insulating film made of a material having a low dielectric constant
The first step of forming a photoresist on the interlayer insulating film
A predetermined pattern provided on the photoresist layer.
Etch the interlayer insulating film using the
To form a groove-shaped opening reaching the substrate.
The second step, the groove-shaped opening in the semiconductor substrate
Forming a protective film on the inner wall surface of the part with hydrogen plasma
A fourth step of removing the photoresist layer,
Fifth process for embedding a metal wiring layer in the groove-shaped opening
This is a method for manufacturing a semiconductor device comprising:

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The semiconductor device and the method of manufacturing the semiconductor device according to the present invention employ the above-described technical configuration, and the technical feature thereof is that HSQ or organic SOG is partially used. After processing the containing interlayer film with a photoresist mask, the photoresist is subjected to oxygen plasma ashing and then removed in the order of wet peeling. Before removing the photoresist using oxygen plasma, or before using a wet remover Before implementing the processing by
The structure is such that the side surfaces of the HSQ film and the organic SOG are oxidized, nitrided or hydrogenated to protect the internal films.

Further, as a method of forming the protective film,
A method for modifying the surface portion of the HSQ or organic SOG film by a plasma treatment using a gas containing hydrogen or nitrogen and a method for forming the protective film by using UV light treatment in combination are also provided.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A specific example of a semiconductor device and a method of manufacturing the semiconductor device according to the present invention will be described below in detail with reference to FIGS. That is, FIG. 1 is a cross-sectional view showing a configuration of a specific example of a semiconductor device according to the present invention.
In the opening 108 provided between the interlayer insulating films 105 formed on the substrate 1, one end portion is disposed on the wiring portion 103 in contact with the substrate 101 and the other end portion of the wiring portion 103. Semiconductor device 200 in which a via portion 120 made of a metal layer 121 is formed, and a protective film 109 is formed on at least a surface portion of an inner wall portion facing the via portion 120 in the opening portion 108. Semiconductor device 200 is shown.

The interlayer insulating film 105 used in the semiconductor device according to the present invention is desirably made of a material having a low dielectric constant. Is, for example, a Si—H bond or S
It is desirable that the insulating layer be made of one insulating material selected from insulating materials containing an i-CH ₃ bond. Further, in the semiconductor device according to the present invention, at least the surface portion 1 of the inner wall portion of the opening 108 facing the wiring portion 103.
In FIG. 22, a layer 104 of an insulating film different from the interlayer insulating film 105 is formed.

In the semiconductor device 200, another insulating interlayer film 10 is formed on the interlayer insulating film 105.
6 are laminated, and a second wiring 107 is formed on the insulating interlayer film 106. The first wiring 103 and the second wiring 103
Has a structure connected by via 120. Hereinafter, an example of a method for manufacturing the semiconductor device 200 of the above specific example according to the present invention will be described below.

That is, FIGS. 2A to 2C and FIG.
As shown in FIGS. 3A to 3D, an appropriate base layer 102 is formed on a silicon substrate 101, and then the base layer 10 is formed.
The first wiring 103 is formed on the second wiring 103. Next, a first interlayer insulating film 104 made of, for example, a silicon oxide film or the like is applied so as to cover the first wiring 103 from above, and a second interlayer insulating film having a lower dielectric constant is further formed thereon. 105 is formed.

Thereafter, a third interlayer insulating film 106 is formed on the second interlayer insulating film 105. The second wiring 107 is formed on those insulating films. The first wiring 103 and the second wiring 107 are formed in vias 120.
It has a structure connected by. As the insulating film on the side surface of the via 120, the protective film 10 defined in the present invention is used.
9 is formed thin.

The presence of the protective film 109 on the side surface of the via 120 is a structural feature of the present invention. Here, the constituent elements are described. The first interlayer insulating film 104 may be any one of a plasma TEOS oxide film, a monosilane-based plasma silicon oxide film, a monosilane-based plasma silicon oxynitride film, a monosilane-based silicon nitride film, and a plasma silicon oxide film containing fluorine. Can be used.

Next, the second interlayer insulating film 1 which is a low dielectric constant film
05 is, for example, HSQ, organic SOG, or Si-H
A structure in which at least a part is formed by a bond or a Si—CH ₃ bond is configured. This second interlayer insulating film 10
There is no change in the film quality of the portion in contact with the protective film 109 around the via 120 of No. 5 and other portions.

[0026] In the present invention, those wherein the protective film 109,
The second interlayer insulating film 105 is formed by hydrogen plasma;
It is desirable to be composed of a hydrogenated layer. Such protection
The protective layer 109 is characteristically formed of the normal second interlayer insulating film 1.
It shows a hardened state as compared with the part of No. 05.

The via 120 is made of a tungsten C film using a titanium nitride film, a titanium film or both as a barrier metal.
A VD film is used. One specific example of the method for manufacturing a semiconductor device according to the present invention is a method for manufacturing a semiconductor device in which a wiring portion 103 is provided between interlayer insulating films 105 formed on a substrate 101. The method for manufacturing a semiconductor device includes a first step of forming an appropriate wiring portion on the semiconductor substrate, and a step of forming an interlayer insulating film made of a material having a low relative dielectric constant on the semiconductor substrate having the wiring portion. In the second step of forming, a photoresist is applied on the interlayer insulating film, and the interlayer insulating film is etched to reach the wiring portion by using a predetermined pattern opening provided in the photoresist layer as a mask. A third step of forming a groove-shaped opening, a fourth step of forming a protective film on the inner wall surface of the groove-shaped opening in the semiconductor substrate, and a fifth step of removing the photoresist layer Work A manufacturing method of a semiconductor device and a city.

In the method of manufacturing a semiconductor device according to the present invention, the material having a low relative dielectric constant is one insulating material selected from insulating materials containing a Si—H bond or a Si—CH 3 bond. It is composed. In addition,
In the description, the fourth step described above includes the step of adding a hydrogen atom.
The protective film is formed using plasma containing
Is desirable.

On the other hand, the manufacture of the semiconductor device according to the present invention
In the method, the fifth step is that at least oxygen plasma
Removing and removing the photoresist layer using
With stripper containing ammonium fluoride or amine
Including any of the steps of stripping and removing the photoresist layer.
It is desirable that it is what you are doing.

Hereinafter, a specific example of the method for manufacturing a semiconductor device according to the present invention will be described in more detail. First, in the present invention, an element (not shown) such as a transistor is formed on a silicon substrate 101, and aluminum Al (copper may be used by sputtering) on a base 102 having an insulating film on the surface. ) Layer 103 having a thickness of 300 nm to 800 n
m.

As shown in FIG. 2A, a barrier metal 130 such as TiN / Ti having a thickness of 30 nm to 200 nm is provided below the Al wiring 103 for bonding to a lower element or the like. And a film 131 of TiN or the like as an anti-reflection film at the time of lithography.
Is formed with a thickness of 10 nm to 100 nm. Subsequently, HSQ, which is a second interlayer insulating film having a low dielectric constant described later, is formed on the entire surface of the base 102 and the wiring portion 103.
For the purpose of improving the adhesion between the resin and the substrate 101 or the base 102, a first interlayer insulating film 104 is formed by coating.

The first interlayer insulating film 104 is conformally formed by forming a silicon oxide film, a fluorine-containing silicon oxide film, or a silicon oxide film with a thickness of 20 nm to 100 nm along a pattern by, for example, a plasma CVD method. I do. The first interlayer insulating film 104 is preferably formed as thin as possible in order to reduce the relative dielectric constant of the entire interlayer insulating film 105.

Next, in the present invention, a second interlayer insulating film 105 made of HSQ resin is applied on the surface of the first interlayer insulating film 104 so as to have a thickness of 200 nm to 1000 nm. To 150 ° C, 150 to 250 ° C, 2
Heating is performed under a nitrogen atmosphere at a temperature condition of 50 to 300 ° C. for about 1 to 10 minutes for temporary firing. The semiconductor device having the preliminarily fired second interlayer insulating film 105 made of HSQ is put into a firing furnace and fired in a nitrogen atmosphere at 350 to 500 ° C. for about 1 hour to obtain a structure shown in FIG. Is formed.

Next, a third interlayer insulating film 106 is formed on the second interlayer insulating film 105 by plasma CVD.
After forming a photoresist layer 110 on the third interlayer insulating film 106, an opening is formed using the photoresist layer 110 using a predetermined pattern. I do. Thereafter, using the patterned photoresist layer 110 as a mask, the third and second interlayer insulating films 106 and 105 and the first interlayer insulating film 104 are subjected to an etching process, and FIG.
As shown in (B), a via hole 111 is formed.

Here, the substrate 101 is introduced into a chamber where plasma can be generated. In the present invention, as a method of generating plasma, for example, a parallel plate reactor or ICP, helicon, EC
Plasma can be generated using a source such as R or microwave. Into these chambers, for example, 100 SCCM to 1000 SCCM of nitrogen, 50 SCCM to 500 SCCM of hydrogen, or both, or an ammonia gas containing nitrogen or hydrogen in a constituent element is introduced, and the temperature in the chamber is set to 100 ° C. to 300 ° C.
Set to.

When microwaves are used, the power should be 5
A nitrogen plasma, a hydrogen plasma, or both plasmas are generated in the range of 00W to 1500W. By this treatment, the film on the surface of the HSQ film becomes dense, and the HSQ film shown in FIG.
As shown in FIG. 7, a protective film 109 having a Si—N bond and a Si—H bond formed in a part of the surface is formed.

By this process, a photoresist stripping process is performed for about 5 minutes by introducing oxygen at a power of 300 to 600 W and about 100 to 400 sccm.
As shown in (A), it was found that the HSQ film hardly deteriorated even after the photoresist was stripped. A predetermined metal is buried in the via hole 111 of the semiconductor device having such a structure to form a contact, and a second wiring 107 is formed on the upper surface of the contact as shown in FIG. The device is completed.

However, as a result of the experiment, if the oxygen plasma treatment is performed for 10 minutes or more at the time of removing the photoresist, the surface of the HSQ film 105 starts to deteriorate.
Therefore, as shown in FIG. 3B, plasma treatment is performed again with a gas containing nitrogen or hydrogen under the same conditions as in FIG. 2C. As a result, the Si—OH bond partially formed by the oxygen plasma treatment is replaced with a Si—N bond or a Si—OH bond.
-H bond. In addition, the surface of the HSQ film layer becomes dense again by this treatment, and the Si—N bond and the Si
-H bonds are formed. That is, the protection film 109 is formed again.

The protective film 109 of the HSQ film removes a photoresist strip residue and a stripper such as ethanolamine having an amine group in an etching residue process by using a wet stripper which is subsequently performed. H, which is the second interlayer insulating film 105 protected by the protective film 109 even when a wet stripper containing
SQ film quality does not deteriorate.

In particular, the etching of the HSQ film itself, which is a concern when a wet stripping solution containing ammonium fluoride is used, does not occur at all, and the via pattern has a bowing shape as shown in FIG. It will not be.
Further, in the present invention, the amine-containing stripping solution contains 10 to 90 vol% of ethanolamine, and the stripping solution containing ammonium fluoride contains 0.1 vol.
A material containing 1% to 5% by volume of ammonium fluoride may be used.

In such a case, the processing temperature is from 25 ° C. to 90 °.
It is desirable to carry out at 10 ° C. for about 10 seconds to about 10 minutes. Finally, the via 121 is buried in the via pattern 120 with a metal such as tungsten, and then the second wiring layer 107 is formed, thereby completing the semiconductor device 200 as shown in FIG.

In the present embodiment, an example of plasma treatment with a gas containing nitrogen or hydrogen before performing the oxygen plasma stripping and before performing the process with the wet stripping solution has been described. It may be performed before only one of the processes. In the first embodiment of the present invention described above, the HSQ film is deteriorated by the oxygen plasma treatment by performing the plasma treatment with nitrogen or hydrogen, modifying the surface of the HSQ film and forming the protective film. Can be prevented.

Further, a stripper containing an amine group,
Even if the treatment with the stripping solution containing ammonium fluoride is carried out, not only does the quality of the HSQ film not deteriorate, but also
The HSQ film itself is not etched by ammonium fluoride, and the formation of the bowing shape of the via can be prevented. Therefore, a leak between vias, a short circuit, and a failure in embedding metal in the next step do not occur. Also, S
Since no i-OH bond was formed after the treatment, HSQ
An effect that the relative dielectric constant of the film does not increase can be expected.

Next, a second specific example of the semiconductor device according to the present invention and its manufacturing method will be described in detail with reference to FIGS. That is, for example, as shown in FIG. 4, the semiconductor device 200 in the second specific example according to the present invention is provided between interlayer insulating films 204 formed on a substrate 201. One end of the substrate 201 or the base 20 is inserted into a groove 211 having an opening
2 is a semiconductor device 200 in which a wiring portion 208 that is in contact with 2 is buried and a protective film 207 is formed on a surface of an inner wall portion facing the wiring portion 208 in the opening 210.

The interlayer insulating film 204 in this specific example
Is desirably made of a material having a low relative dielectric constant as in the above-described specific example, and the material having the low relative dielectric constant is made of an insulating material containing a Si-H bond or a Si-CH ₃ bond. It is desirable that it be made of one selected insulating material. Further, in the second specific example of the present invention, an insulating film layer different from the interlayer insulating film 204, such as a TEOS oxide film, is formed on the surface of the interlayer insulating film 204 except for the opening 210. It is desirable that the insulating film layer 205 composed of the above is formed.

That is, the difference between the semiconductor device according to the second embodiment of the present invention and the first embodiment is that the first embodiment is different from the first embodiment.
In the second specific example, after the wiring portion is formed, the interlayer insulating film is processed to form the protective film. There is a structure that is embedded. That is, the elements of each structure can be the same as those described in the first specific example.

That is, in the second specific example, the base 2 including the transistor formed on the silicon substrate 201 is formed.
A first plasma TEOS oxide film 203, an organic SOG 204, and a second plasma TEOS oxide film 205 are formed in this order from below on 02. The upper three layers are processed, and the processed groove portion 211 is provided in the grooved wiring metal 208.
Are formed.

An organic SOG protective layer 207 is formed on the surface of the interlayer insulating film 204 in contact with the side wall of the trench wiring metal 208. One specific example of the method for manufacturing a semiconductor device according to the present invention is a method for manufacturing a semiconductor device 200 in which a wiring portion 208 is provided between interlayer insulating films 204 formed on a substrate 201. hand,
The method of manufacturing the semiconductor device includes a method of forming an interlayer insulating film 20 made of a material having a low dielectric constant on the semiconductor substrate 201.
First, a photoresist 206 is applied on the interlayer insulating film 204 to form the photoresist layer 2.
The interlayer insulating film 204 is etched using the predetermined pattern opening 230 provided in
01 forming a groove-shaped opening 231 reaching the first opening 231.
Step, opening of the groove portion in the semiconductor substrate 201
Third Step of Forming Protective Film 207 on Surface of Inner Wall of Mouth 231
, A fourth step of removing the photoresist layer 206, and a fifth step of embedding the metal wiring layer 208 in the groove-shaped opening 231.

The material having a low relative dielectric constant in this embodiment is formed of one insulating material selected from insulating materials containing a Si—H bond or a Si—CH ₃ bond. Preferably, the fourth step is to form the protective film 207 using a plasma containing at least one atom selected from oxygen, nitrogen and hydrogen.

Further, in the fourth step, the protective film may be formed using ozone, and an atmosphere containing at least one atom selected from oxygen, nitrogen and hydrogen may be used. The protective film may be formed by performing ultraviolet irradiation in a medium or an atmosphere containing ozone. Further, in the second specific example, between the fourth step and the fifth step, the residue of the photoresist layer and the deposit at the time of dry etching are further removed by a stripper. It is desirable to include the step 4a.

It is preferable that the step 4a includes a step of stripping and removing the photoresist layer with a stripping solution containing at least ammonium fluoride or an amine. To describe the configuration of the second specific example according to the present invention in more detail, in the second specific example, first, a first base is formed on a base 202 including a transistor formed on a silicon substrate 201. A plasma TEOS oxide film 203 is formed to a thickness of about 100 nm. An organic SOG film 204 containing Si—CH ₃ bonds is applied thereon (the organic SOG used here is methylsilsesquioxane having a dielectric constant of 2.8) and is coated with a thickness of about 500 nm, and then about 200 ° C. Of the hot plate at about 400 ° C in a firing furnace.
Time firing is performed.

Further, a second plasma TEOS oxide film 205 having a thickness of 150 nm is formed thereon. Next, a photoresist 206 is formed thereon, and the photoresist 206 is processed by exposure and development. Using the photoresist 206 as a mask, a second plasma TEOS oxide film 205 and an organic SOG 20
4 Then, processing of the first plasma TEOS oxide film 203 is performed.

Here, the wafer is placed on a plate heated to 300 ° C. in a normal pressure atmosphere, and the process is performed while irradiating UV (ultra violet) light in an O ₃ (ozone) gas atmosphere. Organic SOG 204 by the etching process
When this process is performed where the side wall of the organic SOG 204 is exposed, the Si—CH ₃ bond only at the surface of the organic SOG 204 is easily broken by the O ₃ gas excited by the UV light and replaced by the Si—O bond. Organic SOG protective layer 207
Is formed (FIG. 4A).

Even if the shape of the etching process is a reverse taper, the UV-O ₃ treatment is more isotropic than the way of ions such as reactive ion etching, so that the side wall is sufficiently protected. The effect can be exhibited regardless of the shape of the etching process. In this method, the thickness of the protective film 207 on the side wall of the organic SOG, that is, the oxidation depth was as small as about 50 nm. Thereafter, the photoresist is removed by ICP plasma ashing using oxygen gas.

At this time, since the surface of the side wall of the organic SOG 204 is formed of the organic SOG protective layer 207 by the UV / O ₃ treatment, the inside of the organic SOG 204 is not degraded and the Si—CH
_{The three} bonds do not replace the Si—OH bonds leading to moisture absorption. Next, wet peeling is performed. And this groove 23
First, a 50 nm TiN film is formed as a barrier metal by MOCVD, and the CVD is continuously performed without breaking vacuum.
A 50 nm Cu-CVD film was formed by the method.

After that, the Cu film formed by the plating method is
m, and the groove wiring metal 208 shown in the figure was formed on the front surface.
(FIG. 5 (B)). And after that metal CMP is performed
The wiring metal 208 is formed only in the groove 231 (FIG. 5).
(C)). In this method of forming a protective film, the gas is_ThreeUse gas
But, for example, NH_Three, N_TwoH _Two, N_TwoH_Four, Etc. N_X
H_Y(X = 1,2 y = 2-4)
You may.

Although an example of an organic SOG has been described here, the same effect can be expected with an HSQ film. Also Si
It goes without saying that the present invention can be applied to a film containing a -H bond or a Si-CH3 bond. After processing the insulating film containing organic SOG with a photoresist mask, before removing the photoresist, irradiate with ultraviolet light UV (Ultra Violet) light while in an O ₃ gas atmosphere or N _X H _Y (X = 1 to 2, Y = 2-4) By processing the wafer in a gas atmosphere, a protective layer is formed on the surface of the organic SOG.

Since the protective layer protects the organic SOG from being deteriorated by the oxygen ashing and the wet peeling process in the subsequent steps, defective embedding of metal and an increase in the dielectric constant of the organic SOG occur.

[0059]

As described above, the semiconductor device and the method of manufacturing the semiconductor device according to the present invention employ the above-mentioned technical configuration. Therefore, when the photoresist used for forming various patterns is removed by oxygen plasma processing. The HSQ film and the organic SOG are not deteriorated by the wet stripping solution used for removing the etching residue, and the film itself is not etched, so that the semiconductor having the insulating interlayer film having a low relative dielectric constant is used. The device can be manufactured.

[Brief description of the drawings]

FIG. 1 is a sectional view showing the structure of a specific example of a semiconductor device according to the present invention.

FIGS. 2A to 2C are cross-sectional views illustrating a manufacturing process of a specific example of a method of manufacturing a semiconductor device according to the present invention according to the procedure.

FIGS. 3A to 3D are cross-sectional views showing a manufacturing process of a specific example of a method of manufacturing a semiconductor device according to the present invention in accordance with the procedure.

FIG. 4 is a sectional view showing the structure of another specific example of the semiconductor device according to the present invention.

FIGS. 5A to 5C are cross-sectional views showing a specific example of a conventional method of manufacturing a semiconductor device according to a manufacturing process procedure.

FIGS. 6A and 6B are cross-sectional views showing the structure of a conventional semiconductor device.

[Explanation of symbols]

 1, 101, 201: silicon substrate 2, 102, 202: base 3, 103: first wiring portion 4, 104, 203: first insulating interlayer 5, 105, 204: second insulating interlayer, HSQ Film 6, 106, 205: Third insulating interlayer film 10, 200: Semiconductor device 107: Second wiring portion 108: Opening 109, 207: Protective film 110, 206 ... Photoresist layer 111, 120: Via hole portion 121 ... Connector part 122 ... Surface part of opening inner wall 208 ... Metal for groove wiring

Continuation of the front page (56) References JP-A-8-316228 (JP, A) JP-A-5-13405 (JP, A) JP-A-5-55387 (JP, A) JP-A-1-198050 (JP) JP-A-11-87503 (JP, A) JP-A-9-330979 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 21/31-21/3213 H01L 21/768

Claims (10)

(57) [Claims] 1. A low dielectric constant formed on a substrate.
Provided between the interlayer insulating films made of
In the opening, one end of which is in contact with the substrate,
It consists of a metal layer placed on the other end of the wiring section.
And a via portion formed on the semiconductor device.
The interlayer insulation at least in contact with the via portion at the opening
A protective film formed by hydrogen plasma on the inner wall surface of the edge film
A semiconductor device characterized by being present. 2. The material having a low relative dielectric constant is Si-
Select from insulating materials containing H bond or Si-CH3 bond
It should be noted that it is composed of one selected insulating material.
2. The semiconductor device according to claim 1, wherein: 3. The method according to claim 1 , wherein said wiring portion and said wiring portion are connected to each other through said opening.
An insulating film different from the interlayer insulating film between the interlayer insulating films
3. The layer according to claim 1, wherein
13. The semiconductor device according to claim 1. 4. A low dielectric constant formed on a substrate.
Provided between the interlayer insulating films made of
One end is in contact with the substrate in a groove having an opening
The wiring part is embedded and there is no contact in the groove.
The surface of the inner wall in contact with the wiring is formed with hydrogen plasma.
Semiconductor characterized in that a formed protective film is formed
apparatus. 5. The material having a low relative dielectric constant is Si-
Select from insulating materials containing H bond or Si-CH ₃ bond
It should be noted that it is composed of one selected insulating material.
5. The semiconductor device according to claim 4, wherein: 6. The surface of the interlayer insulating film excluding the opening.
An insulating film layer different from the interlayer insulating film is formed.
6. The semiconductor device according to claim 4, wherein
Place. 7. A low dielectric constant formed on a substrate.
Wiring is provided between the interlayer insulating films made of different materials
A method of manufacturing a semiconductor device, comprising:
The method for manufacturing the device includes a first process for forming an appropriate wiring portion on the semiconductor substrate.
The lower the relative permittivity on the semiconductor substrate having the wiring portion
A second step of forming an interlayer insulating film made of a material, applying a photoresist on the interlayer insulating film,
A predetermined pattern opening provided in the photoresist layer is used as a mask.
Then, the interlayer insulating film is etched to reach the wiring portion.
A third step of forming a groove-shaped opening that reaches the inner surface of the groove-shaped opening in the semiconductor substrate;
Manufacturing a semiconductor device, comprising: a fourth step of forming a protective film on a surface with hydrogen plasma ; and a fifth step of removing the photoresist layer.
Method. 8. The material having a low relative dielectric constant is Si-
Select from insulating materials containing H bond or Si-CH3 bond
It should be noted that it is composed of one selected insulating material.
8. The method for manufacturing a semiconductor device according to claim 7, wherein: 9. The method according to claim 5, wherein the fifth step includes the step of:
A process for peeling and removing the photoresist layer using a zuma
And stripper containing ammonium fluoride or amine
Any of the steps of stripping and removing the photoresist layer
8. The semiconductor device according to claim 7, comprising:
Manufacturing method. 10. An interlayer insulating film formed on a substrate.
A method of manufacturing a semiconductor device in which a wiring portion is provided in
The method for manufacturing a semiconductor device comprises a material having a low dielectric constant on the semiconductor substrate.
In the first step of forming an interlayer insulating film, a photoresist is applied on the interlayer insulating film and the photoresist is applied.
A predetermined pattern opening provided in the photoresist layer is used as a mask.
Then, the interlayer insulating film is etched to reach the substrate.
A second step of forming a groove-shaped opening reaching the inner wall surface of the groove-shaped opening in the semiconductor substrate;
A third step of forming a protective film on the surface with hydrogen plasma, a fourth step of removing the photoresist layer, and a fifth step of embedding a metal wiring layer in the groove-shaped opening.
Degree, fabrication of a semiconductor device, characterized in that and a metropolitan
Method.