JPH09312339A - Semiconductor device and manufacture of semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent deterioration of a transistor caused by moisture or hydroxyl groups contained in an SOG film while maintaining the favorable flatness by the SOG film. SOLUTION: A MOS transistor is completed by forming a gate insulating film 2, a gate electrode 3, and source and drain regions 4 on an Si substrate 1. Then, a silicon oxide film 5 is made all over the surface of the device, and thereon an organic SOG film 6 is made, and then argon ions are implanted into this SOG film 6 so as to decompose the organic components within the film and reduce the moisture and hydroxyl groups contained in the film. The SOG film is reformed and the moisture and hydroxyl groups contained in the film decrease, and the SOG film gets hard to absorb water, and gets hard to give adverse influence upon the transistor.

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 manufacturing method thereof, and more particularly to a technique of forming an interlayer insulating film between a plurality of wirings or on a transistor.

[0002]

2. Description of the Related Art In recent years, in multi-layer wiring adopted in highly integrated semiconductor devices, inter-wiring contact (via contact)
There is a demand for lower resistance and improved wiring reliability.

In addition, semiconductor devices are becoming more highly integrated, and it is required to reduce the diameter of contact holes (also synonymous with via holes). However, if the diameter of the contact hole is reduced, it becomes difficult to deposit a wiring material having a sufficient thickness in the contact hole. Therefore, it has been proposed to deposit a suitable metal (tungsten, aluminum, nickel, copper, etc.) in the contact hole by the CVD method to form a plug connecting the first layer wiring and the second layer wiring. .

Among them, blanket-tungsten CV
The D method has attracted attention as an important technique for forming a multi-layer wiring because it can fill tungsten in the contact hole with good coverage.

In the blanket-tungsten CVD method, not only the contact hole but also the interlayer insulating film in which the contact hole is formed, the tungsten is grown, and then only the tungsten on the insulating film is etched back. For example, it is shown in JP-A-4-307934 (H01L21 / 265).

[0006]

In the multilayer wiring forming technique as in the conventional example, if the surface of the interlayer insulating film is not flat, the wiring formed on the upper portion of the interlayer insulating film has a step and a failure such as a disconnection occurs. Is caused.

Therefore, the surface of the interlayer insulating film (that is, the surface of the device) must be as flat as possible. As described above, a technique for planarizing the surface of a device is called a planarization technique, and has become more and more important with miniaturization and multilayering of wiring.

In the flattening technique, there is an SOG film as an interlayer insulating film that is most frequently used, and in particular, the flattening technique utilizing the flow characteristics of the interlayer insulating film material has been actively studied.

SOG is a general term for a solution in which a silicon compound is dissolved in an organic solvent and a film containing silicon dioxide as a main component formed from the solution.

To form the SOG film, first, a solution of a silicon compound dissolved in an organic solvent is dropped on the substrate and the substrate is rotated. Then, the film of the solution is formed thicker in the concave portion and thinner in the convex portion, so as to relieve the step on the substrate formed by the wiring.
As a result, the surface of the coating of the solution is planarized.

Next, when heat treatment is performed, the organic solvent evaporates and the polymerization reaction proceeds to form an SOG film having a flat surface.

As shown in the general formula (1), the SOG film contains an inorganic SO containing no organic component in the silicon compound.
There are a G film and an organic SOG film containing an organic component in a silicon compound as represented by the general formula (2).

[SiO ₂ ] _n ... (1) [R _x SiO _Y ] _n ... (2) (n, X, Y: integer, R: alkyl group or aryl group) The inorganic SOG film has a moisture content. In addition to containing a large amount of hydroxyl groups and hydroxyl groups, it is more fragile than a silicon oxide film formed by the CVD (Chemical Vapor Deposition) method, and if the film thickness is 0.5 μm or more, cracks tend to occur during heat treatment. is there.

On the other hand, since the organic SOG film has a portion where the bond is closed by an alkyl group or an aryl group in the molecular structure, the generation of cracks during heat treatment is suppressed, and the film thickness is set to about 0.5 to 1 μm. be able to. Therefore, if an organic SOG film is used, an interlayer insulating film having a large thickness can be obtained, and sufficient flattening can be performed even on a large step on the substrate.

Here, when the SOG film is adopted as the interlayer insulating film, if the insulating property and mechanical strength of the SOG film are concerned, the insulating property and mechanical property are usually added in addition to the property of blocking moisture and hydroxyl groups. Insulating film with high strength SO
It is performed to intervene in the upper layer or the lower layer of the G film.

However, even with such a structure, since the SOG film containing water and hydroxyl groups is used, the fear of affecting various elements on the semiconductor substrate cannot be eliminated.

As will be described later, when an interlayer insulating film having a three-layer structure of silicon oxide film / SOG film / silicon oxide film is formed on a MOS transistor, the SOG film is formed on the SOG film despite the presence of the silicon oxide film. It has been confirmed in an experiment that the water content and the hydroxyl group contained adversely affect the MOS transistor and shorten the life of the transistor.

Further, in the conventional example, when an SOG film is adopted as an interlayer insulating film and a tongue-ten plug is formed on the SOG film by using the blanket-tungsten CVD method, voids, cracks or cracks are formed. There is a problem that the tungsten plug is imperfectly formed in the contact hole due to film peeling.

FIG. 29 is a photomicrograph of a cross-sectional state of a contact hole (via hole) formed in an organic SOG film when a tungsten film is formed by the blanket tungsten CVD method by the cross-section SEM method. It can be seen that the tungsten has an imperfect shape. It is considered that this is because the reaction gas for forming tungsten such as WF ₆ cannot sufficiently enter into the contact hole because H ₂ O and CH ₃ are desorbed from the organic SOG film. In addition, FIG.
As shown in FIG. 5 and FIG. 26, it is also a cause that recesses are formed in the contact holes.

Although less than the inorganic SOG film, since the organic SOG film also contains water and hydroxyl groups, these water and hydroxyl groups adversely affect the tungsten plug, deteriorating the electrical characteristics and corroding. Such problems may occur.

The present invention relates to a semiconductor device and a method for manufacturing the same, and an object thereof is to obtain good flatness by an insulating film while preventing deterioration of device characteristics.

[0022]

According to another aspect of the present invention, there is provided a semiconductor device in which a conductive plug is formed in a contact hole for connecting a lower conductive portion and an upper conductive portion formed via an interlayer insulating film. In the above, at least a part of the interlayer insulating film is a layer containing impurities.

According to a second aspect of the semiconductor device, the conductive plug is made of a tungsten material, and the layer containing the impurities is made of a polymer material.

According to a third aspect of the present invention, there is provided a method of manufacturing a semiconductor device, wherein a conductive plug is formed by a CVD method in a contact hole for connecting a lower conductive portion and an upper conductive portion formed via an interlayer insulating film. An impurity having kinetic energy is introduced into at least a part of the interlayer insulating film before forming the conductive plug.

According to a fourth aspect of the method of manufacturing a semiconductor device, a step of forming a lower conductive portion on a substrate, a step of depositing an interlayer insulating film on the lower conductive portion, and at least one of the interlayer insulating films. A step of introducing an impurity having a kinetic energy into a layer of the part, a step of forming a contact hole communicating with the lower conductive part in the interlayer insulating film, and a step of forming a conductive plug in the contact hole by a CVD method. And a step of forming an upper conductive portion so as to be electrically connected to the conductive plug.

In the method of manufacturing a semiconductor device according to a fifth aspect of the present invention, the conductive plug is made of a tungsten material and the layer into which the impurities are introduced is made of an organic polymer.

According to a sixth aspect of the present invention, in the method of manufacturing a semiconductor device, the conductive plug is made of a tungsten material, and the layer for introducing the impurities is an inorganic SOG film.

According to a seventh aspect of the semiconductor device, an insulating film containing impurities is formed on the transistor formed on the substrate.

Further, in the semiconductor device according to the eighth aspect, the insulating film is made of a polymer material.

According to a ninth aspect of the semiconductor device, a second insulating film such as a silicon oxide film is provided between the transistor and the insulating film.

According to a tenth aspect of the method of manufacturing a semiconductor device, a step of forming an organic polymer film on a substrate on which a transistor is formed, and a step of introducing impurities having kinetic energy into the organic polymer film. It includes and.

Further, in the semiconductor device manufacturing method of the eleventh aspect, the step of introducing an impurity having kinetic energy into the organic polymer film is performed by ion implantation.

According to a twelfth aspect of the present invention, there is provided a method of manufacturing a semiconductor device, wherein an insulating film such as a silicon oxide film is formed on the surface of the substrate before the organic polymer film is formed.

In the method for manufacturing a semiconductor device according to the thirteenth aspect, heat treatment is performed after introducing an impurity having kinetic energy into the organic polymer film.

Further, the manufacturing method of the semiconductor device according to claim 14 uses organic SOG as the organic polymer.

That is, by incorporating impurities into the interlayer insulating film such as the SOG film by a method such as ion implantation, the film is modified, moisture and hydroxyl groups contained in the film are reduced, and the film is less likely to absorb water. Therefore, a metal plug of tungsten or the like can be satisfactorily formed in the contact hole formed in the interlayer insulating film.

By incorporating impurities into the insulating film such as the SOG film by a method such as ion implantation,
The film is modified so that the water content and the hydroxyl groups contained in the film are reduced and the film is less likely to absorb water, and the transistor is less likely to be adversely affected.

[0038]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) A manufacturing method according to a first embodiment of the present invention will be described with reference to FIGS.

Step 1 (see FIG. 1a): (100) p-type (or n-type) single crystal silicon substrate 1 on gate insulating film 2 (film thickness: 10 nm) and gate electrode 3 (film thickness: 200)
nm). Then, by using the ion implantation method with the gate insulating film 2 and the gate electrode 3 as a mask, n
By doping with a type (or p-type) impurity, the source / drain regions 4 are formed in a self-aligned manner to complete the MOS transistor.

Step 2 (see FIG. 1b): The silicon oxide film 5 (film thickness:
500 nm) is formed. The gases used in this plasma CVD method are monosilane and nitrous oxide (SiH ₄ + N _2).
O), monosilane and oxygen (SiH ₄ + O ₂ ), TEOS
(Tetra-ethoxy-silane) and oxygen (TEOS + O ₂ ), and the film formation temperature is 300 to 900 ° C.

Step 3 (see FIG. 1c): Silicon oxide film 5
An organic SOG film 6 is formed on the substrate. The composition of the organic SOG film 6 is [CH ₃ Si (OH) ₃ ] and its film thickness is 400 nm.
It is.

The formation method is as follows. First, an alcoholic solution of a silicon compound having the above composition (for example, IPA + acetone) is dropped on the substrate 1 to rotate the substrate at a speed of 5400.
By spinning at rpm for 20 seconds, a coating of this solution is formed on the substrate 1. At this time, the film of the alcohol-based solution is formed so as to be thicker in the concave portion and thinner in the convex portion than the step on the substrate 1 so as to reduce the step. As a result, the surface of the film of the alcohol-based solution is flattened.

Next, in a nitrogen atmosphere, 100 ° C. for 1 minute, 200 ° C. for 1 minute, 300 ° C. for 1 minute, 22 ° C.
When the heat treatment is sequentially performed for 1 minute at 300 ° C. for 30 minutes, the alcohol system evaporates and the polymerization reaction proceeds to form the organic SOG film 6 having a flat surface.

Then, by using the ion implantation method, argon ions (Ar ⁺ ) are doped into the organic SOG film 6 under the conditions of an acceleration energy: 140 keV and a dose amount: 1 × 10 ¹⁵ ions / cm ² to obtain an organic component. And decomposes water and hydroxyl groups contained in the film. As a result, the organic SOG film 6 is changed to an SOG film (hereinafter referred to as a modified SOG film) 7 that does not contain organic components and contains only a small amount of water and hydroxyl groups.

Step 4 (see FIG. 2a): A silicon oxide film 8 (film thickness: 200 nm) is formed on the modified SOG film 7 by using the plasma CVD method. The conditions for forming the silicon oxide film 8 are the same as those for the silicon oxide film 5.

Step 5 (see FIG. 2b): Anisotropic etching using a mixed gas system of carbon tetrafluoride and hydrogen as an etching gas is performed to form via holes in the films 5, 7 and 8 on the source / drain regions 4. 9 is formed.

Step 6 (see FIG. 2c): Using a magnetron sputtering method, a titanium nitride thin film 10 is formed on the silicon oxide film 8 including the inside of the via hole 9.

Step 7 (see FIG. 3a): After cleaning the inside of the via hole 9 by sputter etching using an inert gas (for example, Ar), the titanium nitride thin film including the inside of the via hole 9 is blanket-tungsten CVD method. Tungsten 11 is formed on 10.

The formation conditions are as follows: temperature: 450 ° C., pressure: 90 Torr, working gas: tungsten hexafluoride (WF)
₆ , flow rate 70 sccm) + hydrogen (H ₂ , flow rate 420 sccm) (gas flow rate ratio: H ₂ / WF ₆ = 6) is appropriate, but the temperature is 4
In the range of 25 ℃ ~475 ℃, gas flow rate ratio (H ₂ / WF ₆₎
Can be appropriately adjusted within a range of 5 to 70.

Step 8 (see FIG. 3b): Titanium nitride thin film 1
0 and the formed tungsten 11 are anisotropically completely etched back until the silicon oxide film 8 is exposed, and the tungsten 11 is processed so as to be substantially flush with the silicon oxide film 8. 12 is formed. The tungsten plug 12 is used as a source together with the titanium nitride thin film 10 remaining in the via hole 9.
It becomes the drain electrode.

Step 9 (see FIG. 3c): If necessary, the oxide film and the like on the surface of the tungsten plug 12 are removed by sputter etching using an inert gas (Ar, for example).

Next, using the magnetron sputtering method,
An Al alloy film (Al-Si (1%)-Cu (0.5) is formed on the tungsten plug 12 and the silicon oxide film 8.
%)) (Film thickness 500 nm), a Ti film (film thickness 50 nm) and a TiN film (film thickness 20 nm) are sequentially formed from the bottom.

Then, the aluminum alloy film, the Ti film and the TiN film are patterned into a predetermined shape by applying a resist (not shown), exposing and etching by a usual lithography technique and dry etching technique (RIE method or the like). , The upper metal wiring 13 is formed.

As described above, in this embodiment, the interlayer insulating film 14 having the three-layer structure including the silicon oxide film 5, the modified SOG film 7 and the silicon oxide film 8 is formed on the MOS transistor. The modified SOG film 7 is the organic SOG film 6
Similarly to the above, since there is a portion where the bond is closed by an alkyl group or an aryl group in the molecular structure, the occurrence of cracks during heat treatment is suppressed, and the film thickness can be set to about 0.5 to 1 μm.

Therefore, if the modified SOG film 7 is used, the thickness of the interlayer insulating film 14 can be increased, and sufficient flatness can be achieved even for a large step on the substrate 1.

The modified SOG is formed on each of the silicon oxide films 5 and 8.
The sandwich structure in which the film 7 is sandwiched is adopted in order to enhance the insulating property and mechanical strength of the interlayer insulating film 14 as a whole. Further, the silicon oxide film 5 is provided in order to eliminate the influence of water and hydroxyl groups contained in the modified SOG film 7 on the MOS transistor. The silicon oxide film 8 is provided to prevent the modified SOG film 7 from absorbing moisture in the atmosphere.

Further, since the modified SOG film 7 contains no organic component, the etching for forming the via hole 9 can be performed in a mixed gas atmosphere of carbon tetrafluoride and hydrogen. Therefore, in this etching, even when a photoresist is used as an etching mask, the photoresist is not affected, and the modified SOG film 7 masked by the photoresist is not etched. Therefore, fine via holes 9 can be accurately formed.

Further, since the modified SOG film 7 contains no organic component, the etching rate of the modified SOG film 7 is the same as that of the silicon oxide films 5 and 8, and the photo mask used as the etching mask. The modified SOG film 7 does not shrink during the ashing process for removing the resist.

Therefore, the modified SOG film 7 is not cracked and the via hole 9 is not recessed. Therefore, the tungsten 11 can be sufficiently embedded in the via hole 9, and the contact between the source / drain electrode and the source / drain region 4 can be improved.

Since the modified SOG film 7 does not contain an organic component and contains only a small amount of water and hydroxyl groups, one or both of the silicon oxide films 5 and 8 are omitted and the modified SOG film 7 is omitted. Can also be used in a single layer or two layers.

Next, the results of examining the structure and various characteristics of the modified SOG film 7 will be described.

Regarding the structure of the modified SOG film 7, FT-
IR method (Fourier Transform Infrared Spectroscopy),
Evaluation was carried out using the TDS method (Thermal Desorption Spectroscopy), and the results were also examined together with the evaluation results of plasma resistance, heat resistance and hygroscopicity. Regarding the electrical characteristics of the modified SOG film 7, MOS (Metal Oxide S) using an aluminum electrode is used.
A capacitor was manufactured and evaluated using the high frequency CV method.

The stability of the film was evaluated by focusing on heat resistance, plasma resistance, moisture permeability and hygroscopicity. The heat resistance was evaluated by focusing on the change in film thickness before and after heat treatment in a nitrogen atmosphere.

Further, the desorbed gas is analyzed by the TDS method, and the infrared absorption spectrum (FT-IR) by the FT-IR method is analyzed.
It was examined in comparison with changes in IR spectrum).

The plasma resistance was evaluated by focusing on the change in film thickness and the change in infrared absorption spectrum before and after exposure to plasma (conditions for ashing the resist).

The hygroscopicity and moisture permeability were evaluated by focusing on the changes in the infrared absorption spectrum before and after being left in a clean room and before and after the pressure cooker test (PCT).

The thickness of each of the SOG films 6 and 7 depends on the cross-section SEM (S
It was evaluated using the canning electron microscope) method. The electrical characteristics of each of the SOG films 6 and 7 were evaluated by using a high frequency CV method (frequency: 1 MH _Z ) after manufacturing a MOS capacitor using an aluminum electrode on a (100) n-type single crystal silicon substrate. After forming the electrodes, the MOS capacitor is placed in a forming gas (H ₂ / N ₂ = 1/9) at 450 ° C. for 1 hour.
Heat treatment was performed for 5 minutes. (A. Structural Change of Modified SOG Film 7) <A-1. Chemical bond (FT-IR) in the modified SOG film 7
Method)> FIG. 4 shows a result of measuring the infrared absorption spectrum by the FT-IR method immediately after various ions are injected into the organic SOG film 6. The ion implantation conditions are: acceleration energy: 140 KeV, dose amount: 1 × 10 ¹⁶ atom
a s / cm ^2, heat treatment for 30 minutes at 300 ° C. after the ion implantation is performed. The same result can be obtained even if the heat treatment after the ion implantation is omitted.

In FIG. 4, graph 3-1 shows organic SOG.
Immediately after formation of the film 6 (before ion implantation is performed), graph 3
-2 is immediately after implantation of silicon fluoride (SiF ₃ ) ions, Graph 3-3 is immediately after implantation of boron fluoride (BF ₂ ) ions, Graph 3-4 is immediately after implantation of argon ions, and Graph 3-4 is 3-5 is immediately after the implantation of phosphorus ions, Graph 3-6 is immediately after the implantation of silicon ions,
Graph 3-4 is the infrared absorption spectrum of the modified SOG film 7 immediately after the boron ion implantation, and graph 3-8 is the infrared absorption spectrum of the modified SOG film 7 immediately after the fluorine ion implantation.

As shown in graph 3-1, before the ion implantation, the wave number (WAVE NUMBER): about 3000 cm ^-1 and 1250c.
An absorption peak due to organic components is seen near m ^-1 .
The absorption peak around 3000 cm ^-1 is due to the expansion and contraction of the C-H bond, and the absorption peak around 1250 cm ^-1 is due to the angle change of the C-H bond.

However, as shown in graphs 3-2 to 3-8, after the ion implantation, about 3000 cm ^-1 and 1250 cm are obtained.
^No absorption peak near ^-1 . Also, graph 3-2
As shown in 3-8, it is understood that the infrared absorption spectrum of the modified SOG film 7 does not change even if the ion species to be injected is changed. Therefore, by implanting ions, organic S
It can be seen that the organic components contained in the OG film 6 are decomposed.

By the way, if the modified SOG film 7 contains water and hydroxyl groups, it is 3600 cm ⁻¹ and 930 cm ^−1.
An absorption peak due to the hydroxyl group should be seen in the vicinity.

The absorption peak near 3600 cm ^-1 is H-
This is due to the expansion and contraction of the OH bond of OH and Si-OH. However, such an absorption peak is not seen in graphs 3-2 to 3-8. Therefore, it is understood that immediately after the ion implantation, the water content and the hydroxyl group contained in the modified SOG film 7 are reduced as compared with the organic SOG film 6.

FIG. 5 shows the results of measuring the infrared absorption spectrum before and after the ion implantation into the organic SOG film 6 by the FT-IR method. The ion implantation conditions and ion species are the same as those in FIG. 4, and the infrared absorption spectrum of the modified SOG film 7 does not change even if the ion species are changed.

In FIG. 5, graph 4-1 is an organic SOG.
Immediately after the film 6 is formed, graph 4-2 is immediately after ion implantation, graph 4-3 is after ion implantation and is exposed to the atmosphere in the clean room for one day, and then graph 4-4 is ion implanted. After being done, in the atmosphere in the clean room 10
It is an infrared absorption spectrum of the modified SOG film 7 immediately after being exposed for a day.

As shown in graphs 4-2 to 4-4, 3600 cm ^-1 and 9 even after the lapse of time from the ion implantation.
The absorption peak near 30 cm ^-1 does not become large.
Therefore, it can be seen that the water content and the hydroxyl group contained in the modified SOG film 7 do not increase with time.

FIGS. 6 and 7 show the results of measuring the infrared absorption spectrum by the FT-IR method when the dose amount of the ions implanted into the organic SOG film 6 was changed.
The ion implantation conditions are shown in FIG. 6 for acceleration energy of 30 KeV and for FIG. 7 in acceleration energy of 140 KeV, and heat treatment is performed at 300 ° C. for 30 minutes after ion implantation. .

The same result can be obtained even if the heat treatment after the ion implantation is omitted. Further, the ion species to be implanted are the same as those shown in FIG. 4, and the infrared absorption spectrum of the modified SOG film 7 does not change even if the ion species are changed.

In FIGS. 6 and 7, graphs 5-1 and 6-1 are immediately after the formation of the organic SOG film 6, and graphs 5-2 and 6-2 are dose amounts: 1 × 10 ¹⁴ atoms / cm ² , graphs 5-3 and graph 6-3 show dose amount: 1 × 10 ¹⁵ atom
s / cm ² , Graph 5-4 and Graph 6-4 are dose amount: 1
It is an infrared absorption spectrum in the case of × 10 ¹⁶ atoms / cm ² .

As shown in graphs 5-1 to 6-4, as the dose amount of ions increases, 3600 cm ^-1 and 930 cm ^-1.
The absorption peak in the vicinity is small. Therefore, by increasing the dose of implanted ions, the modified SOG
It can be seen that the water content and the hydroxyl groups contained in the film 7 are reduced. If the dose is 1 × 10 ¹⁴ atoms / cm ² ,
The water content and the hydroxyl groups contained in the film are increased more than immediately after the formation of the organic SOG film 6, but the ratio is extremely small.

As described above, according to this embodiment, the organic S
Since the water content and the hydroxyl groups contained in the OG film 6 are not increased, it is possible to prevent a defect such as a poisoned via from occurring in the via hole 9 without providing a step of etching back the organic SOG film 6.

FIG. 8 shows the infrared absorption spectrum of the organic SOG film 6 immediately after the implantation of argon ions, which is shown by FT-IR.
The result measured by the method is shown. The conditions of ion implantation are acceleration energy: 140 KeV, dose amount: 1 × 1.
It is 0 ¹⁵ atoms / cm ² .

In the modified SOG film 7, --CH ₃ (about 300
0 cm ^-1 vicinity) and Si-CH ₃ (1250cm ^-1 vicinity) absorption peak is not observed about. This suggests that the organic components in the organic SOG film 6 were decomposed. Also, O-
It can also be seen that the absorption intensities of H (near 3500 cm ^-1 ) and Si-O (near 1100 cm ^-1 ) do not change significantly before and after ion implantation.

Since argon is an inert element, it is considered that the energy of the injected ion bombardment is the main factor in the above process. Further, as shown in FIG. 4, similar results were obtained with other ions, suggesting that a process independent of the ion species to be implanted is the main factor. (B. Stability of Modified SOG Film 7) <B-1. Heat resistance> First, as an index of heat resistance, the modified S
The evaluation was made by focusing on the reduction in the film thickness of the OG film 7. FIG. 9 shows a modified S formed by implanting argon ions into the organic SOG film 6.
A change in film thickness when the OG film 7 is heat-treated for 30 minutes in a nitrogen atmosphere will be described. The conditions for ion implantation are
Acceleration energy: 140 KeV, Dose amount: 1 × 10 ¹⁵
atoms / cm ² .

When the heat treatment is applied to the organic SOG film 6, the film thickness decreases as the heat treatment temperature increases. It is considered that this decrease in film thickness is due to the film becoming denser as the heat treatment temperature increases. On the other hand, modified SOG
The film 7 does not decrease in thickness even if heat-treated at 800 ° C. In addition, the film thickness of the modified SOG film 7 is 800 ° C. for the organic SOG film 6.
It is almost the same as the film thickness when it is heat-treated at. From this, it is understood that the modified SOG film 7 is densified to the same extent as when the organic SOG film 6 is heat-treated at 800 ° C. <B-2. Residual stress> In FIG. 10, when the organic SOG film 6 is processed into a fine line shape and then argon ions are implanted to form a modified SOG film (Ar ⁺ implantation),
When heat-treated for 30 minutes in a nitrogen atmosphere (Thermal t
reatment) and exposure to oxygen plasma (Oxygen plasm
a) Horizontal (Horizontal) and vertical (Ver) of each film
The result of measuring the shrinkage ratio in the (tical) direction is shown.

In the case of heat treatment or oxygen plasma treatment, contraction occurs in both the horizontal and vertical directions, but in the case of ion implantation,
It can be seen that the film shrinks in the vertical direction (film thickness direction), but does not shrink in the horizontal direction (film width direction). This result shows that when ions are implanted into the organic SOG film 6, the film becomes dense, but stress does not remain so much in the film. When the residual stress was actually measured, it was about −4 × 10 ⁸ dyn
The value was as low as e / cm ² (for example, the residual stress when ion-implanted into a silicon oxide film formed by a plasma CVD method using TEOS and oxygen is about −2 × 10 5
⁹ dyne / cm ² ). Further, the organic SOG film 6 is formed to a depth of 60
No cracks or peeling of the film occurred even if the film was modified to 0 nm at a time. <B-2. Thermal desorption gas characteristics> FIG. 11 shows the organic SOG film 6
The modified SOG film 7 formed by injecting argon ions into the substrate is heat-treated for 30 minutes in a nitrogen atmosphere, and the result of evaluation using the FT-IR method is shown.

It can be seen that in the heat treatment at 400 ° C. or higher, the absorption peaks predicted to be related to Si—H (around 900 cm ⁻¹ and 2100 to 2300 cm ⁻¹ ) gradually decrease with increasing temperature.

FIG. 12 shows the result of the heat treatment of the modified SOG film 7 in a nitrogen atmosphere for 30 minutes and the evaluation by the TDS method. The ion implantation conditions are the dose amount: 1 × 1.
0 ¹⁵ atoms / cm ² , acceleration energy: 140 KeV.

Desorption of hydrogen is observed in the heat treatment at 400 ° C. or higher. Since the behavior of the absorption peak predicted to be related to Si-H observed by the FT-IR method agrees with the tendency, it is considered that hydrogen dissociated from Si-H was observed by TDS analysis. As a result, around 900 cm ^-1 and 21
The absorption between 00 and 2300 cm ⁻¹ is considered to be the absorption related to Si—H.

Si-- formed by implanting ions
In the process of forming the H bond, hydrogen dissociated by ion bombardment (hydrogen dissociated from carbon constituting the methyl group, S
It is considered that hydrogen (dissociated from i-OH or H ₂ O) is involved. That is, the dangling bond of silicon formed by dissociation of oxygen and carbon,
It is considered that the hydrogen of or is terminated.

Further, the modified SOG film 7 is formed by using the TDS method.
And the organic SOG film 6 are compared, the modified SOG film 7
The relative intensity of each m / e in H ₂ (m / e = 2); 13, C
H ₃ (m / e = 15); 0.1, H ₂ O (m / e = 28); 2.4, CO
₂ (m / e = 44); 2.5.

On the other hand, the relative intensity of each m / e in the organic SOG film 6 is 1.0, which is the same for H ₂ , CH ₃ , H ₂ O, CO and CO ₂ . In this way, the modified SOG film 7 has a higher H
Desorption of ₂ O (m / e = 18) and CH _X (m / e = 14,15) is small, and H ₂ (m / e = 2) and CO _X (m / e = 28,44) are large. I found out. <B-4. As an index of plasma resistance> oxygen plasma resistance, the film thickness reduction of the modified SOG film 7 was focused and evaluated. FIG. 13 shows a change in film thickness when the modified SOG film 7 formed by implanting argon ions into the organic SOG film 6 is exposed to oxygen plasma. The ion implantation conditions are: acceleration energy: 140 KeV, dose amount: 1 × 10 ¹⁵ atoms /
It is cm ^2.

When the organic SOG film 6 was exposed to oxygen plasma, the film thickness was reduced by 16%, while the modified SOG film 7 was formed.
It was found that the film thickness did not decrease when the film was exposed to oxygen plasma. However, the thickness of the modified SOG film 7 is the organic SOG.
It is reduced by 25% as compared with the membrane 6. From the above results, it was found that when the ion implantation was performed under the condition that the organic component was decomposed and disappeared, it was modified into a film having excellent oxygen plasma resistance. In addition, since the film thickness decreases more when ion implantation is performed than when exposed to oxygen plasma,
It is considered that the density of the film is higher when the ions are implanted.

Next, the ashing resistance when only the film surface was modified by the ion implantation method was evaluated. In FIG.
Infrared absorption spectrum before and after the ashing process is FT-I
The result measured by R method is shown. The ashing was performed using a μ wave down flow under the condition that a resist having a film thickness of 10 μm could be removed.

From FIG. 14, it was found that when argon ions were implanted with an implantation energy of 20 KeV, the organic SOG film inside the modified SOG film remained unmodified. Furthermore, it was found that the amount of methyl groups in the underlying organic SOG film 6 did not decrease even if the sample was subjected to ashing treatment. As a result, it was found that the ashing resistance is improved even in the region where the dose of ions is shallow. <B-5. Moisture Permeability and Hygroscopicity> It is known that when the organic SOG film 6 is exposed to oxygen plasma, organic components are decomposed. In that case, the components in the film increase, and S
It is already known that the infrared absorption intensity for i-O increases.

Therefore, the modified SO modified by ion implantation is used.
The hygroscopic properties of the G film 7, the organic SOG film 6 exposed to oxygen plasma, and the unmodified organic SOG film 6 were compared.

FIG. 15 shows the results of evaluating the water content in the film by leaving it in the atmosphere in a clean room before, after, and after each treatment. The water content in the film was determined using the area intensity of absorption (near 3500 cm ⁻¹ ) related to the O—H group in the infrared absorption spectrum as an index. The ion species at this time is argon, and the implantation energy is 140 KeV. It can be seen that when exposed to oxygen plasma, the water content increases not only before and after the treatment but also after one day. On the other hand, in the case of ion implantation, not only does the amount increase after ion implantation, but the increase in water content is small even when left in the atmosphere in the clean room. Furthermore, when ion-implanted, it absorbed less moisture than the unmodified one.

FIG. 16 shows a pressure cooker test (PCT) (a humidification test, which is a condition in this embodiment, 120 ° C. and 2 atm) for the purpose of investigating the moisture permeability of the modified SOG film 7. The results are shown in (saturated vapor pressure atmosphere). Organic SO using FT-IR method
The area intensity of the absorption peak (near 3500 cm ⁻¹ ) relating to OH in the G film 6 was obtained and the relationship with the PCT time was plotted.

A sample (Ar ⁺ 20 KeV) in which only the very surface was modified by the ion implantation method was prepared, and the result was compared with that of the film modified (Ar ⁺ 140 KeV) and unmodified. I found the following.

(1) PC with unmodified organic SOG film 6
When it is T, the absorption intensity around 3500 cm ^-1 (related to OH) shows a dramatic increase.

(2) In the modified film, the increase in absorption intensity near 3500 cm ^-1 (related to OH) is small. A sample in which only the film surface was modified is comparable to a sample in which the entire film has been modified.

(3) When only the surface of the film is modified, there are unmodified parts inside the film, so that when moisture reaches the unmodified part inside the PCT film, as shown in (1) It is expected to show significant changes. However, the change was small in the range of the PCT time this time (up to 60 hours later).

From the above results, it is considered that by implanting ions, a layer suppressing moisture permeability could be formed.

Next, the results of examining the following various characteristics will be described. 17 and 18 show changes in CV special characteristics due to the difference in dose amount in the modified SOG film 7. From this, it is understood that the dose amount needs to be 1 × 10 ¹⁵ atoms / cm ² or more.

FIG. 19 shows the dose dependency of the leak current in the modified SOG film 7. However, the film thickness of the organic SOG film 6 is such that no ion implantation is performed and the dose amount is 1 × 10 ¹⁵ atoms /
cm ² is 2500 Å for 1 × 10 ¹⁶ atoms / cm ² , and dose is 300 for 1 × 10 ¹⁴ atoms / cm ^2.
It is 0Å. At a dose of 1 × 10 ¹⁴ atoms / cm ² , the film quality is poor because the leak current is large despite the thick organic SOG film.

FIG. 20 shows a change in infrared absorption spectrum due to a difference in dose amount in the modified SOG film 7. No ion implantation (organic SOG film 6), dose: 1 × 10
^{At 14} atoms / cm ² , the C—H peak is large, and many organic components remain. Also, the dose amount: 1 × 10 ¹⁴ atoms / cm
^In No. ² , since the peak of O-H is large, it can be seen that the film absorbs water or water is generated in the film. On the other hand, dose amount: 1 × 10 ¹⁵ atoms / cm ² ,
At 1 × 10 ¹⁶ atoms / cm ² , since the OH peak is small, it can be seen that the film is a good quality film with little water content.

FIG. 21 shows changes in CV characteristics due to heat treatment of the modified SOG film 7. It can be seen that the modified SOG film 7 is thermally stable because the CV curve hardly changes even when heat treatment is performed. However, if heat treatment is applied,
The hysteresis becomes slightly larger.

FIG. 22 shows oxygen plasma resistance depending on the difference in heat treatment temperature. The dielectric constant of the modified SOG film 7 hardly changes even if the heat treatment temperature is increased by performing oxygen plasma treatment. From this, it can be seen that the film is of good quality and stable.

FIG. 23 shows oxygen plasma resistance depending on the difference in dose amount. When the dose amount is 1 × 10 ¹⁴ atoms / cm ² , the oxygen plasma treatment significantly increases the dielectric constant, which is about the same as that without ion implantation (organic SOG film 6). From this, it is understood that it is important to decompose the organic component in the organic SOG film 6 by ion implantation in order to improve the oxygen plasma resistance.

FIG. 24 shows changes in film thickness when the dose amount of argon ions is changed when the modified SOG film 7 formed by implanting argon ions into the organic SOG film 6 is exposed to oxygen plasma. . The conditions of the oxygen plasma treatment are as follows: microwave downflow device, microwave output: 1000 W, gas species: mixed gas of oxygen, nitrogen and hydrogen, pressure: 400 Pa, treatment temperature: 2
20 ° C., treatment time: 2.5 min, acceleration energy of ion implantation: 140 KeV.

As described with reference to FIG. 13, when the organic SOG film 6 is exposed to oxygen plasma, the film thickness is greatly reduced. Even when the modified SOG film 7 is exposed to oxygen plasma, the film thickness also decreases when the dose amount is 1 × 10 ¹⁴ atoms / cm ² . Therefore, it is understood that a dose amount of 1 × 10 ¹⁵ atoms / cm ² or more is required to prevent the film shrinkage of the modified SOG film 7 when exposed to oxygen plasma.

FIG. 25 shows acceleration energy: 20 KeV,
3 is a micrograph of a cross-sectional state of a via hole 9 observed with a cross-section SEM method when the dose amount of argon ions is 1 × 10 ¹⁵ atoms / cm ² . Further, FIG. 26 shows acceleration energy: 90 KeV, dose amount of argon ion: 1 × 1.
7 is a micrograph of a cross-sectional state of the via hole 9 observed with a cross-sectional SEM method in the case of 0 ¹⁵ atoms / cm ² . FIG. 27 is a micrograph of the cross-sectional state of the via hole 9 observed by a cross-section SEM method when the acceleration energy is 140 KeV and the dose amount of argon ions is 1 × 10 ¹⁵ atoms / cm ² .

While the recesses are generated in FIGS. 25 and 26, the recesses are not generated in FIG.

From the above results, in order to prevent the film contraction of the modified SOG film 7, the acceleration energy is 140 KeV or more,
It can be seen that the dose amount of argon ions is required to be 1 × 10 ¹⁵ atoms / cm ² or more.

In FIG. 28, under the same conditions as in FIG. 12, H ₂ O (m /
The results of evaluation using the TDS method for e = 18) are shown.
As described with reference to FIG. 12, the modified SOG film 7 is formed of H ₂ O (m /
It can be seen that desorption for e = 18) and CH ₃ (m / e = 15) is small.

29 and 30 are sectional SEMs showing a sectional state when the tungsten plug 12 is formed in the via hole 9 by using the blanket-tungsten CVD method.
It is a micrograph observed by the method. 29 shows the case where the organic SOG film 6 is not ion-implanted as described above, and FIG. 30 shows the modified SOG obtained by injecting argon ions into the organic SOG film 6.
When the film 7 is formed (dose amount: 1 × 10 ¹⁵ atoms / c
m ² , acceleration energy: 140 KeV).

As shown in FIG. 29, when the argon ions are not implanted, the tungsten plug 12 is not sufficiently embedded in the via hole 9. On the other hand, as shown in FIG. 30, in the modified SOG film 7, the inside of the via hole 9 is completely filled with the tungsten plug 12. This is Figure 1
2 and FIG. 28, in the modified SOG film 7, H ₂ O
It is considered that this is because desorption of CH ₃ and CH ₃ is small.

FIG. 31 shows variations in resistance value when 1000 via holes 9 in which tungsten plugs or aluminum electrodes are formed are connected in series. 31a shows the case where the via hole 9 and the aluminum electrode are formed in the organic SOG film 6 without ion implantation, and FIG. 31b shows the case where the via hole 9 and the aluminum electrode are formed in the modified SOG film 7 into which argon ions are implanted. Shows the case where the via hole 9 and the tungsten plug are formed in the modified SOG film 7 into which argon ions are implanted.

The diameter of the via hole is 0.7 μm.

In the case of the modified SOG film 7, the resistance value is the organic S
It can be seen that the resistance value is much smaller than the resistance value of the OG film 6.

32 to 36, from the silicon oxide film 8 / organic SOG film 6 (modified SOG film 7) / silicon oxide film 5 on the NMOS transistor as shown in FIGS. The results of various experiments are shown using a test device having an inter-layer insulating film.

FIG. 32 shows the drain voltage dependence of the hot carrier life of the NMOS transistor (the time until Gm (mutual conductance) deteriorates at a certain rate, which is one of the parameters indicating the life of the transistor). It can be seen that the hot carrier life is extended by about two digits in the case of using the modified SOG film 7 (especially, the acceleration energy is 140 keV), as compared with the case of using the organic SOG film without ion implantation. .

FIGS. 33 and 34 show the threshold Vt before and after the acceleration test (test in which the voltage of 5 V is continuously applied to the transistor of the test device for 2 hours under the temperature condition of 200 ° C.). 33 shows the threshold value Vt before the acceleration test, and FIG. 34 shows the amount of change in the threshold value Vt before and after the acceleration test.

As shown in FIG. 33, before the acceleration test, there is almost no change in the threshold value of both the organic SOG film without ion implantation and the modified SOG film 7.

However, as shown in FIG. 34, in the case of using the organic SOG film which is not ion-implanted, the threshold value Vt greatly changes before and after the test, whereas in the modified SOG film,
Using film 7 (especially acceleration energy of 140 keV
), There is almost no change in the threshold value Vt regardless of the gate length. This result indicates that the threshold characteristics of the MOS transistor are stable for a long time.

FIG. 35 shows the amount of change in Gm of the transistor before and after the acceleration test similar to FIG.

Whereas the one using the organic SOG film which has not been ion-implanted has a large change in Gm before and after the test, the one using the modified SOG film 7 (particularly, one having an acceleration energy of 140 keV) ) Is G regardless of the gate length
Almost no change in m is seen. This result indicates that Gm of the MOS transistor is stable for a long time.

It should be noted that in FIGS. 31 to 35, the modified SOG is used.
The improvement effect of the film 7 formed under the condition of the acceleration energy of 20 keV is slight as compared with the film formed under the condition of the acceleration energy of 140 keV. This is shown in Figure 3.
As shown in 6, the acceleration energy (injection energy) is organic S.
There is almost a positive correlation with the modification depth of the OG film, and it is considered that only the surface layer (about 50 nm) of the organic SOG film 6 was modified when the acceleration energy was 20 keV. (Second Embodiment) A manufacturing method according to a second embodiment of the present invention will be described with reference to FIGS. In the present embodiment, the same components as those in the first embodiment are designated by the same reference numerals and detailed description thereof will be omitted.

Step (1) (see FIG. 37a): p-type (or n)
Type) single crystal silicon substrate 1 on which a gate insulating film 2, a gate electrode 3 and a source / drain region 4 are formed to form a MOS
Complete the transistor. Then, an interlayer insulating film 21 is formed on the entire surface of the device, and a via hole 22 is formed in the interlayer insulating film 21 on the source / drain region 4. After that, an aluminum film is deposited on the entire surface of the device including the inside of the via hole 22 by using a sputtering method, and anisotropic etching is performed so that the aluminum film has a desired pattern, and the source / drain electrodes (source / drain wiring) are formed. ) 15 is formed.

Step (2) (see FIG. 37b): A silicon oxide film 5 is formed on the entire surface of the device. Step (3) (see FIG. 37c): After forming the organic SOG film 6 on the silicon oxide film 5, the organic SOG film 6 is changed to the modified SOG film 7 by ion implantation.

Step (4) (see FIG. 38a): A silicon oxide film 8 is formed on the modified SOG film 7.

Step (5) (see FIG. 38b): Anisotropic etching using a mixed gas system of carbon tetrafluoride and hydrogen as an etching gas is performed to form each film 5, 7, 8 on the source / drain region 4. A via hole 9 is formed in.

Step (6) (see FIG. 38c): A titanium nitride thin film 10 is formed on the silicon oxide film 8 including the inside of the via hole 9 by using a magnetron sputtering method.

Step (7) (see FIG. 39a): By sputter etching using an inert gas (eg Ar),
After cleaning the inside of the via hole 9, a blanket-
Tungsten 11 is formed on the titanium nitride thin film 10 including the inside of the via hole 9 by the tungsten CVD method.

Step (8) (see FIG. 39b): The titanium nitride thin film 10 and the formed tungsten 11 are anisotropically fully etched back until the silicon oxide film 8 is exposed, and the tungsten 11 is almost flush with the silicon oxide film 8. The tungsten plug 12 is formed in the via hole 9 by processing so as to be uniform.

Step (9) (see FIG. 39c): If necessary, the oxide film or the like on the surface of the tungsten plug 12 is removed by sputter etching using an inert gas (Ar, for example).

Next, using the magnetron sputtering method,
An Al alloy film, a Ti film, and a TiN film are sequentially formed on the tungsten plug 12 and the silicon oxide film 8 from below.

Then, an aluminum alloy film, a Ti film and a TiN film are patterned into a predetermined shape by applying a resist (not shown), exposing and etching by a usual lithography technique and a dry etching technique (RIE method or the like). , The upper metal wiring 13 is formed.

As described above, in this embodiment, the wiring 1 is formed on the source / drain wiring 15 with the interlayer insulating film 14 interposed therebetween.
3 is formed. Even in this case, without adversely affecting the MOS transistor and the source / drain wiring 15,
The same operation and effect as those of the first embodiment can be obtained.

The present invention is not limited to the above-mentioned embodiment, and the same effects can be obtained even if it is carried out as follows.

1) Instead of the organic SOG film 6, polyimide, siloxane-organized polyimide, or the like is used. These, including organic SOG films, are collectively referred to as organic polymers (or organic spin coating films).

2) Plasma C is applied to each of the silicon oxide films 5 and 8.
Methods other than VD method (normal pressure CVD method, low pressure CVD method, EC
R plasma CVD method, photo-excitation CVD method, TEOS-CV
A silicon oxide film formed by a D method, a PVD method, or the like is used. In this case, gases used in the normal pressure CVD method are monosilane and oxygen (SiH ₄ + O ₂ ), and the film formation temperature is 400 ° C. or less. The gas used in the low pressure CVD method is monosilane and nitrous oxide (SiH ₄ + N ₂ O), and the film formation temperature is 900 ° C. or less.

3) Each of the silicon oxide films 5 and 8 is replaced with another insulating film (silicon nitride film, silicate glass film, etc.) having a property of high mechanical strength in addition to the property of blocking moisture and hydroxyl groups. The insulating film may be formed by any method such as a CVD method and a PVD method.

4) The source / drain electrode 10 and the wiring 23 are formed of a conductive material other than aluminum (copper, gold, silver, silicide, refractory metal, doped polysilicon, titanium nitride (TiN), tungsten titanium (TiW), etc. Alloy) and their laminated structure.

5) Heat treatment is applied to the modified SOG film 7. In this case, dangling bonds in the modified SOG film 7 are reduced. Hygroscopicity is further reduced, and permeation of moisture is further reduced.

6) The composition of the organic SOG film 6 is represented by the general formula (2)
Replace with the one represented by.

7) The composition of the organic SOG film 6 is represented by the general formula (1)
The inorganic SOG film represented by is replaced by ion implantation into the inorganic SOG film. In this case, moisture and hydroxyl groups contained in the inorganic SOG film can be reduced.

8) The modified SOG film 7 is also used as a passivation film. In this case, an excellent passivation film that can reliably protect the device mechanically and chemically can be obtained.

9) In the above embodiment, argon ions are used as the ions to be injected into the organic SOG film 6, but any ions may be used as long as they can modify the organic SOG film 6.

Specifically, argon ions, boron ions, and nitrogen ions are most suitable. In addition, the following ions can be expected to have a sufficient effect.

Inert gas ions other than argon (helium ion, neon ion, krypton ion, xenon ion, radon ion). Inert gas is organic SOG
Since it does not react with the film 6, there is no possibility that ion implantation will have an adverse effect.

III b, IV b, V other than boron and nitrogen
b, VI b, VII b elemental element ions and their compound ions. In particular, oxygen, aluminum, sulfur, chlorine, gallium, germanium, arsenic, selenium, bromine, antimony,
Elemental element ions of iodine, indium, tin, tellurium, lead and bismuth, and their compound ions.

Among these, regarding the metal element ions, there is a possibility that the dielectric constant of the organic SOG film 6 after ion implantation may decrease, but since the amount thereof is very small, the interlayer insulating film having a particularly high dielectric constant is used. There is no practical problem except when is required.

Group IVa and Va element elemental ions and their compound ions. In particular, elemental elemental ions of titanium, vanadium, niobium, hafnium, and tantalum and their compound ions. Since the oxides of the IVa group and Va group elements have a high dielectric constant, the dielectric constant of the organic SOG film 6 after ion implantation can be increased.

A plurality of types of each ion are used in combination. In this case, a more excellent effect can be obtained by the synergistic action of each ion.

10) In the above embodiment, the organic SOG film 6 is used.
Although ions are implanted in the above, not only ions but also atoms, molecules, and particles having kinetic energy may be used (in the present invention, these are collectively referred to as impurities).

11) As the sputtering method, other than magnetron sputtering, diode sputtering, high frequency sputtering, quadrupole sputtering, or the like may be used.

12) As a method of sputter etching,
In addition to using an inert gas, a reactive gas (for example, CCl
₄ , reactive ion beam etching (R ₆ ) using SF ₆ )
IBE, also called reactive ion milling).

13) The tungsten plug 12 may be replaced with a plug made of another metal (aluminum, nickel, copper, molybdenum, etc.).

14) Titanium nitride is used when blanket-tungsten CVD is used to grow tungsten.
Tungsten nuclei are easily formed and tungsten grows well. Instead of the titanium nitride thin film 10, titanium compounds such as titanium tungsten (TiW) are used as those having similar characteristics. Such a titanium compound provides a low contact resistance and has good adhesion to the substrate. Alternatively, tungsten alone may be used.

15) The silicon oxide film 8 is omitted.

[0161]

According to the present invention, the film is modified by containing impurities in the insulating film such as the SOG film,
Since the water content and the hydroxyl groups contained in the film are reduced and the film is less likely to absorb water, the conductive plug can be well formed in the contact hole formed in the modified film, and the conductive plug and the transistor can be formed. Less likely to have an adverse effect.

Therefore, it is possible to maintain good flatness due to the insulating film while preventing deterioration of device characteristics.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing a manufacturing process of a semiconductor device according to a first embodiment of the invention.

FIG. 2 is a cross-sectional view showing a manufacturing process of the semiconductor device according to the first embodiment of the present invention;

FIG. 3 is a cross-sectional view showing the manufacturing process of the semiconductor device according to the first embodiment of the present invention.

FIG. 4 is a characteristic diagram for explaining the first and second embodiments.

FIG. 5 is a characteristic diagram for explaining the first and second embodiments.

FIG. 6 is a characteristic diagram for explaining the first and second embodiments.

FIG. 7 is a characteristic diagram for explaining the first and second embodiments.

FIG. 8 is a characteristic diagram for explaining the first and second embodiments.

FIG. 9 is a characteristic diagram for explaining the first and second embodiments.

FIG. 10 is a characteristic diagram for explaining the first and second embodiments.

FIG. 11 is a characteristic diagram for explaining the first and second embodiments.

FIG. 12 is a characteristic diagram for explaining the first and second embodiments.

FIG. 13 is a characteristic diagram for explaining the first and second embodiments.

FIG. 14 is a characteristic diagram for explaining the first and second embodiments.

FIG. 15 is a characteristic diagram for explaining the first and second embodiments.

FIG. 16 is a characteristic diagram for explaining the first and second embodiments.

FIG. 17 is a characteristic diagram for explaining the first and second embodiments.

FIG. 18 is a characteristic diagram for explaining the first and second embodiments.

FIG. 19 is a characteristic diagram for explaining the first and second embodiments.

FIG. 20 is a characteristic diagram for explaining the first and second embodiments.

FIG. 21 is a characteristic diagram for explaining the first and second embodiments.

FIG. 22 is a characteristic diagram for explaining the first and second embodiments.

FIG. 23 is a characteristic diagram for explaining the first and second embodiments.

FIG. 24 is a characteristic diagram for explaining the first and second embodiments.

FIG. 25 is a micrograph showing a cross-sectional state of the device in the first and second embodiments.

FIG. 26 is a micrograph showing a cross-sectional state of the device in the first and second embodiments.

FIG. 27 is a micrograph showing a cross-sectional state of the device in the first and second embodiments.

FIG. 28 is a characteristic diagram for explaining the first and second embodiments.

FIG. 29 is a micrograph showing a cross-sectional state of the device in the first and second embodiments.

FIG. 30 is a micrograph showing a cross-sectional state of the device in the first and second embodiments.

FIG. 31 is a characteristic diagram for explaining the first and second embodiments.

FIG. 32 is a characteristic diagram for explaining the first and second embodiments.

FIG. 33 is a characteristic diagram for explaining the first and second embodiments.

FIG. 34 is a characteristic diagram for explaining the first and second embodiments.

FIG. 35 is a characteristic diagram for explaining the first and second embodiments.

FIG. 36 is a characteristic diagram for explaining the first and second embodiments.

FIG. 37 is a cross-sectional view showing the manufacturing process of the semiconductor device according to the second embodiment of the invention.

FIG. 38 is a cross-sectional view showing the manufacturing process of the semiconductor device according to the second embodiment of the present invention.

FIG. 39 is a cross-sectional view showing the manufacturing process of the semiconductor device according to the second embodiment of the invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Silicon substrate 4 Source / drain region (lower conductive part) 5 Silicon oxide film (insulating film, second insulating film) 6 Organic SOG film (organic polymer) 7 Modified SOG film 12 Tungsten plug (conductive plug) 13 Upper layer metal wiring (upper conductive part) 14 Interlayer insulating film 15 Source / drain electrodes (lower conductive part)

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical indication location H01L 21/90 C (72) Inventor Seiki Hirase 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Denki Co., Ltd. (72) Inventor Hiroyuki Aoe 2-5-5 Keihan Hondori, Moriguchi City, Osaka Sanyo Denki Co., Ltd.

Claims (14)

[Claims] 1. A conductive plug is formed in a contact hole for connecting a lower conductive portion and an upper conductive portion formed via an interlayer insulating film, wherein at least a part of the interlayer insulating film is formed. A semiconductor device characterized by being a layer containing impurities. 2. The semiconductor device according to claim 1, wherein the conductive plug is made of a tungsten material, and the layer containing the impurities is made of a polymer material. 3. A contact hole for connecting a lower conductive portion and an upper conductive portion formed via an interlayer insulating film,
A semiconductor device in which a conductive plug is formed by a CVD method, and impurities having kinetic energy are introduced into at least a part of the interlayer insulating film before the conductive plug is formed. Manufacturing method. 4. A step of forming a lower conductive portion on a substrate, a step of depositing an interlayer insulating film on the lower conductive portion, and introducing an impurity having kinetic energy into at least a part of the interlayer insulating film. A step of forming a contact hole communicating with the lower conductive part in the interlayer insulating film, forming a conductive plug in the contact hole by a CVD method, and electrically connecting to the conductive plug. And a step of forming an upper conductive portion, as described above. 5. The method of manufacturing a semiconductor device according to claim 3, wherein the conductive plug is made of a tungsten material, and the layer into which the impurities are introduced is made of an organic polymer. 6. The method of manufacturing a semiconductor device according to claim 3, wherein the conductive plug is made of a tungsten material, and the layer into which the impurities are introduced is an inorganic SOG film. 7. A semiconductor device comprising an insulating film containing impurities formed on a transistor formed on a substrate. 8. The semiconductor device according to claim 7, wherein the insulating film is made of a polymer material. 9. The semiconductor device according to claim 7, wherein a second insulating film such as a silicon oxide film is provided between the transistor and the insulating film. 10. A semiconductor device comprising: a step of forming an organic polymer film on a substrate on which a transistor is formed; and a step of introducing impurities having kinetic energy into the organic polymer film. Manufacturing method. 11. The semiconductor device according to claim 3, wherein the step of introducing impurities having kinetic energy into the organic polymer film is performed by ion implantation. Production method. 12. The method of manufacturing a semiconductor device according to claim 10, wherein an insulating film such as a silicon oxide film is formed on the surface of the substrate before forming the organic polymer film. 13. The method of manufacturing a semiconductor device according to claim 10, wherein heat treatment is performed after introducing an impurity having a kinetic energy into the organic polymer film. 14. Organic SOG as the organic polymer
Was used.
14. The method for manufacturing a semiconductor device according to any one of 2 and 13.