CN1271767A - Cleaning liquid and manufacturing method of semi-conductor device using said cleaning liquid - Google Patents

Abstract

Use a cleaning solution containing condensed ammonium phosphate as the main component, urea or a metamorphic component of urea as an auxiliary agent, and an acid with a hydrogen ion concentration of ^10-4 mol/l or more to remove the second layer exposed from the semiconductor substrate 2. The resist residue 22a on the wiring layer 20 and the buried metal film 14 is buried. Thereby, even if part of the buried film buried in the connection hole is exposed due to the borderless wiring, the resist residue can be reliably removed without dissolving the conductive layer such as the buried layer or the wiring layer.

Description

Cleaning liquid and method for manufacturing semiconductor device using same

The present invention relates to a cleaning solution and a method for manufacturing a semiconductor device using the cleaning solution, and more particularly to a cleaning solution that does not substantially damage wiring layers and buried films and a method for manufacturing a semiconductor device using the cleaning solution. Resist residue remaining on the semiconductor substrate after reactive ion etching (dry etching) using the resist pattern as a mask can be reliably removed.

In semiconductor devices, in order to achieve high-speed and high-performance devices, devices are being miniaturized. Not only components such as transistors, which affect device performance, but also wiring structures must be miniaturized.

In order to form a fine pattern by dry etching using a resist pattern as a mask, it is necessary to make the resist pattern finer and use dry etching with strong anisotropy. As a result, after etching and removing the resist pattern, many resist residues adhere to the fine pattern. Although this resist residue can be removed with a cleaning solution, it is difficult to remove this resist residue with conventional cleaning solutions.

Also, as will be described later, when a part of the upper surface of the buried film buried in the connection hole connected to the wiring layer is exposed, the conventional cleaning solution dissolves the buried film. Next, a method of manufacturing a semiconductor device having a wiring layer will be described with reference to three examples.

First, as a first prior art, a method of manufacturing a semiconductor device having an aluminum wiring layer will be described. Referring to FIG. 26, a first wiring layer 106 made of aluminum alloy or the like is formed on a silicon substrate 102 via an underlying interlayer insulating film 104 such as a silicon oxide film. An interlayer insulating film 108 is formed on the base interlayer insulating film 104 to cover the first wiring layer 106 . A connection hole 110 exposing the surface of the first wiring layer 106 is formed in the interlayer insulating film 108 . In this connection hole 110, a buried metal film 114 containing tungsten is formed via an underlying metal film 112 containing a titanium alloy or the like.

An intermediate metal film (not shown) made of aluminum alloy or the like is formed on the lower metal film 112 and the buried metal film 114 . An upper metal film (not shown) made of a titanium alloy or the like is formed on the intermediate metal film. A resist pattern 122 is formed on the upper metal film. Using the resist pattern 122 as a mask, reactive ion etching is performed on the upper metal film, the intermediate metal film, and the lower metal film to form the second wiring layer 120 . The second wiring layer 120 is composed of an upper metal film 118 , an intermediate metal film 116 , and a lower metal film 112 .

Next, referring to FIG. 27, the oxygen-containing gas is turned into plasma, and the semiconductor substrate 102 is exposed to the plasma gas atmosphere, whereby the resist pattern 122 is removed. Resist residue (not shown) adheres to the surface of the second wiring layer 120 and the like after the removal of the resist pattern 122 . This resist residue can be removed with a predetermined cleaning solution. Therefore, in the semiconductor device, a multilayer circuit structure having the first wiring layer 106 and the second wiring layer 120 can be obtained. The first wiring layer 106 and the second wiring layer 120 are electrically connected through the buried metal film 114 containing tungsten formed in the interlayer insulating film 108 .

Next, as a second prior art, a method of manufacturing a semiconductor device having, for example, a bit line will be described.

Referring first to FIG. 28 , an interlayer insulating film 126 made of a silicon oxide film is formed on a silicon substrate 102 . A bit line contact hole 128 exposing the surface of the silicon substrate 102 is formed in the interlayer insulating film 126 . A buried film 130 containing polysilicon is formed in the bit line contact hole 128 . An underlying metal film (not shown) containing a titanium alloy or a tungsten alloy is formed on the interlayer insulating film 126 and the buried film 130 .

An upper metal film (not shown) containing tungsten or the like is formed on the lower metal film. A resist pattern 136 is formed on the upper metal film. Using the resist pattern 136 as a mask, reactive ion etching is performed on the upper metal film and the lower metal film, whereby the bit line 135 is formed. Bit line 135 is composed of upper metal film 134 and lower metal film 132 .

Next, referring to FIG. 29, the oxygen-containing gas is turned into plasma, and the semiconductor substrate 102 is exposed to the plasma gas atmosphere, whereby the resist pattern 136 is removed. Resist residue (not shown) adheres to the surface of the bit line 135 and the like after the removal of the resist pattern 136 . This resist residue can be removed with a predetermined cleaning solution. Therefore, in the semiconductor device, a structure having the bit line 135 can be obtained. The bit line 135 is electrically connected to other elements (not shown) or the like through the buried film 130 containing polysilicon formed in the interlayer insulating film 126 .

Next, as a third prior art, a method of manufacturing a semiconductor device having copper wiring will be described. The multilayer circuit structure composed of copper wiring described here is called dual damascene.

Referring first to FIG. 30 , an interlayer insulating film 140 is formed on a silicon substrate 102 via an underlying interlayer insulating film 138 formed of a silicon oxide film or the like, and a first wiring groove 142 is formed in the interlayer insulating film 140 . A first wiring layer 146 made of copper is formed in the first wiring groove 142 via a first lower metal film 144 made of titanium alloy or the like.

An interlayer insulating film 148 is formed on the first wiring layer 146 and the interlayer insulating film 140 . A resist pattern 152 is formed on the interlayer insulating film 148 . Using the resist pattern 152 as a mask, reactive ion etching is performed on the interlayer insulating film 148 to form a connection hole 150 exposing the surface of the first wiring layer 146 .

Next, referring to FIG. 31, the oxygen-containing gas is turned into plasma, and the semiconductor substrate 102 is exposed to the plasma gas atmosphere, whereby the resist pattern 152 is removed. Resist residue (not shown) adheres to the surface of the first wiring layer 146 exposed on the side surface and the bottom surface of the connection hole 150 after the removal of the resist pattern 152 . This resist residue can be removed with a predetermined cleaning solution. Then, a predetermined wiring groove (not shown) is formed on the interlayer insulating film 148, and at the same time, a copper film (not shown) is embedded in the wiring groove and the connection hole 150 to form a second wiring layer (not shown). ). Therefore, in the semiconductor device, a multilayer wiring structure having the first wiring layer and the second wiring layer formed of copper wiring can be obtained.

However, the above-mentioned first to third conventional technologies have the following problems, respectively. First, the problems of the first prior art will be described.

In order to adapt to the miniaturization of the device, the width of the wiring layer is reduced to the same order of magnitude as the opening size of the connection hole. On the other hand, processing accuracy of elements formed on a semiconductor substrate and wiring layers electrically connecting the elements differs depending on the photolithography process and the etching process.

As a result, as shown in FIG. 32 , the second wiring layer 120 and the upper surface of the buried metal 114 buried in the connection hole 110 may not be completely in contact with each other, and may be shifted from the connection hole 110 . The wiring structure formed in this way is called borderless (borderless) wiring. In addition, if the wiring layer formed on the upper surface of the connection hole is offset from the connection hole in this way, the connection hole formed on the wiring layer and the wiring layer may be offset from each other in the borderless wiring.

In the case of the borderless wiring shown in FIG. 32 , part of the upper surface of the buried metal 114 buried in the connection hole 110 is exposed. Furthermore, as shown in FIG. 33, resist residue 122a adheres to the surface of the second wiring layer 120 and the exposed buried metal 114 after the resist pattern 122 is removed. The resist residue 122a contains reaction products generated during reactive ion etching.

The resist residue 122a can be removed with a predetermined cleaning solution as described above. An example of such a cleaning solution includes an amine-based organic cleaning solution. The cleaning solution is an organic solvent mainly composed of alkanolamines such as hydroxylamine and ethanolamine. This cleaning solution is characterized by its high dissolving power against resists, and has some corrosive effects on metals such as aluminum and titanium.

When mixed with water, the amine shows strong alkalinity, and the pH value of the cleaning solution is mostly above 10. The tungsten monomer is almost not corroded in this cleaning solution. For example, if immersed in the cleaning solution at a temperature of 60°C for 30 minutes, the corroded amount of tungsten is below 30 angstroms.

However, as shown in FIG. 33, when the removal of the resist residue is carried out in a state where a part of the upper surface of the embedded metal 114 is exposed, the embedded metal film 114 containing tungsten is dissolved at an accelerated rate due to an electrochemical reaction, as shown in FIG. 34. As shown, a large portion of the buried metal film 114 is excavated. As a result, the contact resistance between the first wiring layer 106 and the buried metal film 114 increases or the connection is disconnected, resulting in poor electrical contact.

In addition, this electrochemical reaction is caused by the strong alkalinity of the cleaning solution, and since the silicon substrate 102 is exposed to the atmosphere of plasma gas when the resist is removed, the second wiring layer 120 accumulates electric charges, causing electric shock. chemical reaction.

Next, as another example of the cleaning solution, the cleaning solution described in JP-A-59-5670 can be mentioned. The cleaning liquid is an inorganic cleaning liquid, which is a water-soluble cleaning liquid containing urea or its abnormal components mainly composed of condensed ammonium. The pH of the cleaning solution varies somewhat depending on the amount of urea added, but is generally between 6.5 and 7.5, making the cleaning solution neutral. The cleaning liquid has the characteristics of good cleaning effect on the metal surface and little corrosion to the metal. Furthermore, this cleaning solution is excellent in terms of work safety such as ease of handling and non-pollution, and non-pollution.

However, when this cleaning solution was used to remove the resist residue 122a, it was confirmed that the tungsten-containing embedded metal film 114 was dissolved in the cleaning solution similarly to the amine-based organic cleaning solution. Furthermore, since this cleaning solution is neutral, the amount of dissolved metal film buried is less than when using an amine-based organic cleaning solution.

Next, as still another example of the cleaning liquid, a neutral organic cleaning liquid and a neutral inorganic cleaning liquid can be mentioned. However, when these cleaning solutions were used to remove the resist residue 122a, it was also confirmed that the embedded metal film 114 containing tungsten was dissolved in the cleaning solution.

As described above, in the first prior art, when the conventional cleaning solution is used to remove the resist residue 122a, when a part of the upper surface of the embedded metal film 114 is exposed due to the borderless wiring, the The electrochemical reaction accelerates the dissolution of the tungsten-containing buried metal film 114 . As a result, the contact resistance between the first wiring layer 106 and the buried metal film 114 increases or the connection is disconnected, resulting in poor electrical contact.

Next, problems in the second prior art will be described. As shown in FIG. 35, when the bit line 135 is a borderless wiring, part of the upper surface of the buried film 130 containing polysilicon buried in the bit line connection hole 128 is exposed. Further, as shown in FIG. 36, a resist residue 136a adheres to the surface of the bit line 135 and the exposed buried film 130 after the resist pattern 136 is removed. This resist residue 136a can be removed with a predetermined cleaning solution.

Conventional wiring materials for bit lines use polysilicon films or tungsten alloy films. At this time, as cleaning solutions for removing resist residues, a mixed solution of sulfuric acid and hydrogen peroxide (SPM) and a mixed solution of ammonia and hydrogen peroxide (APM) were used. However, in order to reduce the wiring resistance, low-resistance metals such as titanium or titanium alloys have been used as wiring materials.

However, as shown in FIG. 36, when SPM or APM is used to remove the resist residue attached to the bit line 135 having the lower metal film 132 containing titanium alloy and the upper metal film 134 containing tungsten, the titanium alloy and tungsten will Dissolve in hydrogen peroxide water. Therefore, SPM and APM which have been used so far cannot be used.

Therefore, an ammonia solution can be mentioned as an alternative cleaning solution for SPM and APM. As for the aqueous ammonia solution, it was confirmed that although the amount of corrosion of the tungsten and titanium alloy of the bit line 135 was small, the resist residue 136a could not be sufficiently removed.

In addition, since the ammonia solution has the property of dissolving silicon, the buried film 130 containing polysilicon buried in the bit line contact hole 128 is dissolved in the ammonia solution. As shown in FIG. piece. As a result, the contact resistance between the bit line 135 and the buried film 130 increases or disconnection causes a problem of poor electrical contact.

Next, as another example of the cleaning solution, the above-mentioned amine series organic cleaning solution can be mentioned. Cleaning liquids containing organic solvents contain a large amount of metal impurities in terms of manufacturing methods. Specifically, for inorganic solutions such as SPM and APM, metal impurities such as sodium (Na) and iron (Fe) are below 1 ppb, while for amine series organic cleaning solutions, they contain tens to hundreds of ppb of metal impurities.

Like the first prior art, when an amine-based organic cleaning solution is used in the aluminum wiring formation process, even if metal impurities adhere to the surface of the wiring, etc., the metal impurities are not easily diffused due to the action of the lower metal film 112 formed of a titanium alloy. into components such as transistors located below.

On the other hand, when an amine series cleaning solution is used in the process of forming the bit line, since the position of the bit line is closer to the transistor than to the aluminum wiring, the attached metal impurities are easy to reach the transistor and other components, and the device characteristics will deteriorate. The problem. Therefore, the resist residue 136a adhering to the bit line 135 and the like cannot be removed using an amine-based cleaning solution.

Next, as yet another example of the cleaning solution, the cleaning solution described in the above-mentioned Patent Publication (Shao 59-5670) can be mentioned. However, it has been confirmed that when this cleaning solution is used to remove the resist residue 136a, the cleaning effect is poor and it is difficult to remove the resist residue 136a.

As described above, in the second prior art, if the resist residue 136a is removed using a conventional cleaning solution, the buried film 130 containing polysilicon is dissolved in the cleaning solution in the case of borderless wiring. As a result, the contact resistance between the bit line 135 and the buried film 130 increases or disconnection occurs. In addition, depending on the type of cleaning solution, the resist residue 136a cannot be sufficiently removed.

Next, the problems of the third prior art will be described. As shown in FIG. 38, after removing the resist pattern 152 for forming the connection hole 150 in the interlayer insulating film 148, a resist is attached to the surface of the first wiring layer 146 exposed on the side and bottom of the connection hole 150. Residue 152a. This resist residue 152a is also removed with a predetermined cleaning solution.

An example of such a cleaning solution includes the aforementioned amine-based organic cleaning solution. However, as shown in FIG. 39 , it has been confirmed that the surface of the first wiring layer 146 exposed on the bottom surface of the connection hole 150 is dissolved in the amine-based organic cleaning solution.

In addition, in order to form a second wiring layer (not shown), a second wiring groove is formed in the interlayer insulating film 148 . It was confirmed that when the resist residue in this step was removed, the surface of the first wiring layer 146 exposed on the bottom surface due to the penetration of the cleaning solution into the connection hole 150 was further dissolved in the cleaning solution.

As a result, as shown in FIG. 40, the first wiring layer 146 is dug out, the contact resistance between the second wiring layer 160 and the first wiring layer 146 increases or even breaks, and the first wiring layer 146 and the second wiring layer 160 cannot be connected. good electrical contact.

Next, as yet another example of the cleaning solution, the cleaning solution described in the above-mentioned Patent Publication (Shao 59-5670) can be mentioned. However, it has been confirmed that the resist residue 152a cannot be sufficiently removed when the resist residue is removed using this cleaning solution.

As described above, in the third prior art, when the resist residue 152a is removed using a conventional cleaning solution, the first wiring layer is dissolved in the cleaning solution. In addition, the resist residue 152a cannot be sufficiently removed, depending on the kind of cleaning liquid.

As described above, in the first and second conventional techniques, when removing resist residues, due to the existing cleaning solution, the buried contact hole due to the borderless wiring is buried. When a part of the upper surface of the film is exposed, the exposed surface may be dissolved in the cleaning solution. In addition, in the third prior art, the wiring layer formed on the semiconductor substrate 102 may be dissolved in a conventional cleaning solution.

As a result, the contact resistance between the wiring layer and the buried film may increase, or disconnection may occur, resulting in poor electrical contact. In addition, resist residues could not be sufficiently removed due to the cleaning solution.

The present invention was made in order to solve the above-mentioned problems, and an object thereof is to provide a cleaning solution that reliably dissolves the conductive layer of the embedded film and the wiring layer even in the case of borderless wiring. Remove resist residue. Another object is to provide a method of manufacturing a semiconductor device, which has a residue removal step of removing resist residues using such a cleaning solution.

The cleaning solution according to the first aspect of the present invention is a water-soluble cleaning solution containing condensed ammonium phosphate as a main component, urea or a metamorphic component of urea and an acid as an auxiliary agent. And the hydrogen ion concentration is above 10 ^-4 mol/l.

According to this cleaning solution, the hydrogen ion concentration is above 10 ^-4 mol/l, that is, the pH value of the cleaning solution is below 4. Therefore, resist residue adhering to the surface of the conductive layer exposed from the semiconductor substrate can be reliably removed without the cleaning solution substantially dissolving the conductive layer.

The hydrogen ion concentration is preferably below 10 ^-2 mol/l.

At this time, the pH value of the cleaning solution is above 2. When the conductive layer exposed from the semiconductor substrate contains aluminum or an aluminum alloy, when the pH of the cleaning solution is less than 2, the conductive layer becomes easily dissolved. Therefore, it is desirable that the pH value of the cleaning solution is greater than 2 and less than 4.

The acid is preferably phosphoric or orthophosphoric acid.

At this time, the acid is added as an adjusting agent for adjusting the pH of the cleaning solution. The acid may be nitric acid, sulfuric acid, etc., but phosphoric acid or orthophosphoric acid is preferable from the viewpoint of cleaning effect and solubility to the conductive layer exposed from the semiconductor substrate.

In addition, the degree of polymerization of the condensed ammonium phosphate is preferably 2 or more and 150 or less.

This is because, when the degree of polymerization of the condensed ammonium phosphate exceeds 150, even if the liquid temperature exceeds 90°C, the condensed ammonium phosphate does not dissolve and becomes a slurry, and the cleaning effect is poor. Whereas when the degree of polymerization is less than 2, in the case where the conductive layer exposed from the semiconductor substrate contains aluminum or an aluminum alloy, aluminum or the like is more easily dissolved.

The metamorphic component of urea is preferably biuret or triuret.

They act as buffers by condensing ammonium phosphate, inhibiting the dissolution of the conductive layer exposed from the semiconductor substrate.

The weight ratio of condensed ammonium phosphate to urea or urea metamorphic components is preferably 1:1 to 10:1.

This is because, when urea or urea-abnormal components are added in a large amount exceeding 1:1, the cleaning effect will be poor. And when urea or urea abnormal components are added less than 10:1, the effect of condensed ammonium phosphate on the dissolution of the conductive layer exposed from the semiconductor substrate becomes poor, and the conductive layer is more likely to dissolve.

The concentration of condensed ammonium phosphate is preferably not less than 1% and not more than 40% relative to the total weight percentage of the cleaning solution.

This is because, when the concentration of condensed ammonium phosphate is less than 1% by weight, the effect of removing resist residue is poor. It is very difficult to make the concentration of condensed ammonium phosphate greater than 40% by weight.

The cleaning solution preferably further contains a surfactant.

When the conductive layer exposed from the semiconductor substrate contains aluminum or an aluminum alloy, by adding a surfactant, the melting of the aluminum or aluminum alloy by the cleaning solution can be reduced. In addition, when the conductive layer contains tungsten, its dissolution can also be suppressed by a surfactant.

A method of manufacturing a semiconductor device according to another aspect of the present invention includes a residue removal step. In this residue removal step, the residues at least from the semiconductor are removed using a cleaning solution containing condensed ammonium phosphate as the main component, urea or a metamorphic component of urea as an auxiliary agent, and an acid and having a hydrogen ion concentration of 10 ^-4 mol/l or more. Photoresist residue on the surface of the substrate exposing the conductive layer.

According to this method, since the hydrogen ion concentration of the cleaning solution is above 10 ^-4 mol/l, that is, the pH value of the cleaning solution is below 4, the resist residue can be reliably removed and the cleaning solution has no substantial effect on the conductive layer. dissolve.

As the conductive layer exposed from the semiconductor substrate, specifically, tungsten, tungsten alloy, aluminum, aluminum alloy, copper and copper alloy are preferably contained.

The method preferably includes, before the residue removing step: a step of forming a conductive layer on the semiconductor substrate; a step of forming an insulating film on the semiconductor substrate to cover the conductive layer; a step of forming a resist pattern on the insulating film; A step of etching the insulating film with the resist pattern as a mask to form connection holes exposed from the surface of the conductive layer; and a step of removing the resist pattern, the residue removal step is followed by the removal of the resist pattern after the procedure.

In this case, the resist residue adhering to the surface of the conductive layer exposed from the side and bottom of the connection hole can be reliably removed without substantially dissolving the conductive layer by the cleaning solution.

The above-mentioned method preferably includes before the residue removal step: a step of forming an insulating film on the semiconductor substrate; a step of forming an opening on the insulating film; a step of forming a buried conductor to fill the opening; The process of forming a layer to be a wiring layer; the process of forming a resist pattern on a layer to be a wiring layer; using the resist pattern as a mask to etch a layer to be a wiring layer to form a connection with a buried conductor a step of wiring layer; and a step of removing the resist pattern, the residue removing step is performed immediately after the step of removing the resist pattern, and the conductive layer includes a wiring layer and a buried conductor.

In this case, even if the wiring layer becomes a borderless wiring and a part of the upper surface of the buried conductor is exposed, the resist residue can be reliably removed without substantially dissolving the wiring layer and the buried conductor by the cleaning solution. As a result, an increase in contact resistance between the wiring layer and the buried conductor or disconnection can be prevented.

The buried conductor preferably contains tungsten, and the wiring layer preferably contains aluminum or an aluminum alloy.

In this case, the resist residue can be reliably removed without substantially dissolving the tungsten, aluminum or aluminum alloy in the cleaning solution. As a result, an increase in contact resistance between the wiring layer and the buried conductor or disconnection can be prevented.

The hydrogen ion concentration of the cleaning solution is preferably below 10 ^-2 mol/l.

When the conductive layer comprises aluminum or aluminum alloy, since the hydrogen ion concentration of the cleaning solution is below 10 ^-2 mol/l, that is, the pH value of the cleaning solution is above 2 (below 4), it can inhibit the cleaning solution from affecting the aluminum or aluminum alloy. of the dissolution.

Furthermore, since the cleaning liquid contains a surfactant, it is possible to suppress the dissolution of aluminum or aluminum alloy in the cleaning liquid.

When the conductive layer contains aluminum or an aluminum alloy, it is desirable that the temperature of the cleaning solution is not less than 20°C and not more than 65°C. This is because, when the temperature of the cleaning solution is lower than 20°C, the ability to remove resist residues decreases, and on the other hand, when the temperature of the cleaning solution is higher than 65°C, aluminum or aluminum alloy tends to dissolve in the cleaning solution.

In addition, when the conductive layer does not contain aluminum or aluminum alloy, the temperature of the cleaning solution is not less than 40°C and not more than 100°C.

This is because, when the temperature of the cleaning solution is lower than 40° C., the ability to remove resist residues decreases, and on the other hand, when the temperature of the cleaning solution exceeds 100° C., the cleaning solution evaporates quickly and cannot be used.

In the residue removal step, it is desirable to immerse the semiconductor substrate in a cleaning solution or to spray the cleaning solution on the semiconductor substrate.

FIG. 1 is a cross-sectional view showing one step of a method of manufacturing a semiconductor device according to Embodiment 1 of the present invention.

FIG. 2 is a cross-sectional view showing steps performed after the step shown in FIG. 1 in Example 1. FIG.

3 is a cross-sectional view showing steps performed after the step shown in FIG. 2 in Example 1. FIG.

FIG. 4 is a cross-sectional view showing steps performed after the step shown in FIG. 3 in Example 1. FIG.

5 is a cross-sectional view showing steps performed after the step shown in FIG. 4 in Example 1. FIG.

FIG. 6 is a cross-sectional view showing steps performed after the step shown in FIG. 5 in Example 1. FIG.

FIG. 7 is a cross-sectional view showing steps performed after the step shown in FIG. 6 in Example 1. FIG.

8 is a cross-sectional view showing steps performed after the step shown in FIG. 7 in Example 1. FIG.

Fig. 9 is a diagram showing an equilibrium state based on pH value and oxidation-reduction potential in a tungsten-water system.

10 is a cross-sectional view showing one step of a method of manufacturing a semiconductor device according to Embodiment 2 of the present invention.

FIG. 11 is a cross-sectional view showing steps performed after the step shown in FIG. 10 in Example 2. FIG.

FIG. 12 is a cross-sectional view showing steps performed after the step shown in FIG. 11 in Example 2. FIG.

FIG. 13 is a cross-sectional view showing steps performed after the step shown in FIG. 12 in Example 2. FIG.

FIG. 14 is a cross-sectional view showing steps performed after the step shown in FIG. 13 in Example 2. FIG.

FIG. 15 is a cross-sectional view showing steps performed after the step shown in FIG. 14 in Example 2. FIG.

16 is a cross-sectional view showing one step of a method of manufacturing a semiconductor device according to Embodiment 3 of the present invention.

FIG. 17 is a cross-sectional view showing steps performed after the step shown in FIG. 16 in Example 3. FIG.

FIG. 18 is a cross-sectional view showing steps performed after the step shown in FIG. 17 in Example 3. FIG.

FIG. 19 is a cross-sectional view showing steps performed after the step shown in FIG. 18 in Example 3. FIG.

20 is a cross-sectional view showing steps performed after the step shown in FIG. 19 in Example 3. FIG.

FIG. 21 is a cross-sectional view showing steps performed after the step shown in FIG. 20 in Example 3. FIG.

FIG. 22 is a cross-sectional view showing steps performed after the step shown in FIG. 21 in Example 3. FIG.

FIG. 23 is a cross-sectional view showing steps performed after the step shown in FIG. 22 in Example 3. FIG.

24 is a cross-sectional view showing steps performed after the step shown in FIG. 23 in Example 3. FIG.

25 is a cross-sectional view showing steps performed after the step shown in FIG. 24 in Example 3. FIG.

26 is a cross-sectional view showing one step of the method of manufacturing a semiconductor device according to the first prior art.

FIG. 27 is a cross-sectional view showing steps performed after the step shown in FIG. 26 .

28 is a cross-sectional view showing one step of a method of manufacturing a semiconductor device according to the second prior art.

Fig. 29 is a cross-sectional view showing steps performed after the step shown in Fig. 28 .

30 is a cross-sectional view showing one step of a method of manufacturing a semiconductor device according to the third prior art.

Fig. 31 is a cross-sectional view showing steps performed after the step shown in Fig. 30 .

32 is a cross-sectional view illustrating one step of a method of manufacturing a semiconductor device for explaining problems of the first conventional art.

Fig. 33 is a cross-sectional view showing steps performed after the step shown in Fig. 32 .

Fig. 34 is a cross-sectional view showing steps performed after the step shown in Fig. 33 .

35 is a cross-sectional view showing one step of a method of manufacturing a semiconductor device for explaining problems of the second conventional art.

Fig. 36 is a cross-sectional view showing steps performed after the step shown in Fig. 35 .

FIG. 37 is a cross-sectional view showing steps performed after the step shown in FIG. 36 .

38 is a cross-sectional view showing one step of a method of manufacturing a semiconductor device for explaining problems of the third prior art.

FIG. 39 is a cross-sectional view showing steps performed after the step shown in FIG. 38 .

FIG. 40 is a cross-sectional view showing steps performed after the step shown in FIG. 39 .

Example 1

The cleaning solution according to Example 1 of the present invention and a method of manufacturing a semiconductor device using the cleaning solution will be described. Referring first to FIG. 1, an underlying interlayer insulating film 4 made of a silicon oxide film is formed on a silicon substrate 2 by a CVD method or the like. A metal film (not shown) containing aluminum or an aluminum alloy to be the first wiring layer is formed on the underlying interlayer insulating film 4 by, for example, sputtering. A resist pattern (not shown) is formed on the metal film. Using this resist pattern as a mask, reactive ion etching (dry etching) is performed on the metal film, whereby the first wiring layer 6 is formed. The resist pattern is then removed.

Next, referring to FIG. 2 , an interlayer insulating film 8 made of a silicon oxide film is formed on the underlying interlayer insulating film 4 by CVD or the like to cover the first wiring layer 6 .

Next, referring to FIG. 3 , a resist pattern (not shown) is formed on interlayer insulating film 8 . The interlayer insulating film 8 is reactively ion-etched using the resist pattern as a mask, thereby forming the connection hole 10 exposed from the surface of the first wiring layer 6 . The resist pattern is then removed.

Next, referring to FIG. 4, a lower layer metal film 12 comprising, for example, a titanium alloy such as titanium nitride is formed on the interlayer insulating film 8 by sputtering, and the exposed surface of the first wiring layer 6 and the connection hole 10 are covered. . Next, a tungsten film (not shown) is formed on the lower metal film 12 by CVD, and embedded in the connection hole 10 . By performing etchback on the entire surface of the tungsten film, only the tungsten film is left in the connection hole 10, whereby the buried metal film 14 is formed.

Next, referring to FIG. 5 , an intermediate metal film 16 containing aluminum or an aluminum alloy is formed by, for example, sputtering to cover the base metal film 12 and the buried metal film 14 . An upper metal film 18 containing a titanium alloy is formed on the intermediate metal film 16 by sputtering. Next, referring to FIG. 6 , a resist pattern 22 is formed on the upper metal film 8 . Using the resist pattern 22 as a mask, reactive ion etching is performed on the upper metal film 18, the intermediate metal film 16, and the lower metal film 12, thereby exposing the surface of the interlayer insulating film 8. Thus, the second wiring layer 20 composed of the upper metal film 18 , the intermediate metal film 16 and the lower metal film 12 is formed.

In this step, it is assumed that the second wiring layer 20 becomes a borderless wiring due to misalignment when the resist pattern 22 is formed. Therefore, a part of the upper surface of the buried metal film 14 is exposed.

Next, referring to FIG. 7, the oxygen-containing gas is turned into plasma, and the resist 22 is removed by exposing the silicon substrate 2 to the plasma gas. Resist residue 22 a adheres to the surface of the second wiring layer 20 and the surface of the buried metal film 14 after the removal of the resist 22 .

Next, the resist is removed using a cleaning solution containing condensed ammonium phosphate as the main component, urea or a metamorphic component of urea as an auxiliary agent, and an acid with a hydrogen ion concentration of 10 ^-4 mol/l or higher, that is, a pH value of 4 or lower. agent residue 22a.

If this cleaning solution is used, as will be described in detail later, since the pH value of the cleaning solution is 4 or less, the resist residue 22a can be reliably removed, and the cleaning solution does not substantially dissolve the embedded metal film 14 containing tungsten. . Since the cleaning solution has a pH value greater than 2 and less than 4, the resist residue 22a can be reliably removed, and the cleaning solution does not substantially dissolve the second wiring layer 20 containing aluminum or aluminum alloy.

Therefore, as shown in FIG. 8 , a multilayer wiring structure having the first wiring layer 6 and the second wiring layer 20 in the semiconductor device can be obtained.

As described above, in the step of removing the resist residue 22 a shown in FIG. 7 , this cleaning solution does not substantially dissolve the exposed tungsten-containing embedded metal film 14 . Hereinafter, this point will be described in detail.

Fig. 9 is a graph showing the reaction of tungsten and water in a WH ₂ O-based aqueous solution and the stability regions of various compounds according to pH and redox potential (1998 IEEE International Reliability Physics Symposium Proceedings 36th Annual).

Considering the cleaning solution and the buried metal, in particular, the oxidation-reduction potential on the vertical axis in FIG. 9 approximately corresponds to the potential of the buried metal film 14 . The potential of the buried metal film 14 is a potential generated by exposing the exposed surface of the buried metal film 14 to an oxygen-containing plasma atmosphere.

The mechanism for generating this potential will be described more specifically. First, when the resist pattern 22 is removed, the surfaces of the second wiring layer 20 and the buried metal film 14 exposed by the removal of the resist pattern 22 are exposed to an oxygen-containing plasma atmosphere. Oxygen radicals exist in the plasma atmosphere. Oxygen radicals have very high reactivity and oxygen is a strongly electronegative atom, so once oxygen radicals come into contact with the surface of the second wiring layer 20 , the oxygen radicals can easily take electrons from the second wiring layer 20 . As a result, the second wiring layer is positively charged. In this way, a positive potential is generated on the buried metal film 14 connected to the second wiring layer 20 . Hereinafter, this oxidation-reduction potential is simply referred to as potential.

Therefore, referring to FIG. 9 , when the pH value of the cleaning solution is in the region above 4 and the potential is in the positive region, tungsten dissolves in the cleaning solution in the form of WO ₄ ^-2 . On the other hand, even if the potential is in the positive region, when the pH value of the cleaning solution is below 4, so-called oxides (non-conductors) of WO ₂ , WO ₃ , and W ₂ O ₃ are formed on the surface of tungsten, and tungsten insoluble. In addition, when the potential is in a relatively low negative range, tungsten does not dissolve in the state of tungsten in the cleaning solution, regardless of the pH value.

Therefore, since the pH value of the cleaning solution is below 4, even if the embedded metal film 14 is positively charged, the cleaning solution does not substantially dissolve the embedded metal film containing tungsten.

On the other hand, for the sake of comparison, the case where the washing liquid of the first prior art is used will be described. For example, the pH value of the amine-based organic cleaning solution is above 10. In addition, the pH value of the inorganic cleaning solution mainly composed of condensed ammonium phosphate is 6.5 to 7.5. These cleaning solutions have a pH greater than 4. Therefore, as shown in FIG. 9, when the pH value is greater than 4 and the potential is positive, the buried metal film containing tungsten will dissolve in the existing cleaning solution.

The second wiring layer 20 contains aluminum or an aluminum alloy. Since aluminum is easy to dissolve when the pH value of the cleaning solution is less than 2, it is desirable that the pH value of the cleaning solution is greater than 2 and less than 4.

Sulfuric acid, nitric acid, etc. may be used as the acid to be added as an adjusting agent for adjusting the pH of the cleaning solution, but phosphoric acid is preferred, preferably orthophosphoric acid, from the viewpoint of cleaning effect and solubility of wiring materials.

The degree of polymerization of the condensed ammonium phosphate contained in this cleaning solution is desirably not less than 2 and not more than 150. This is because, when the degree of polymerization of the condensed ammonium phosphate exceeds 150, the condensed ammonium phosphate does not dissolve even at a liquid temperature of 90° C. or higher, and the cleaning effect decreases.

On the other hand, when the degree of polymerization is less than 2, the aluminum or aluminum alloy forming the second wiring layer 20 is easily dissolved.

The urea modification component added as an auxiliary agent is desirably biuret (Biuret: H ₂ NCONHCONH ₂ ) or triuret (Triuret: H ₂ NCONHCONHCONH ₂ ). In addition, the auxiliary agent mentioned here means the thing which has the effect of suppressing the dissolution of the wiring material which forms a wiring layer in a cleaning liquid by condensed ammonium phosphate.

The ratio of condensed ammonium phosphate to urea and its metamorphic components is preferably 1:1 to 10:1 by weight. This is because, when urea and its metamorphic components are added so much that the weight ratio exceeds 1:1, the cleaning effect is poor.

On the other hand, when urea and its metamorphic components are added in a weight ratio of less than 10:1, the effect as an auxiliary agent is reduced, and the wiring material forming the wiring layer is more easily dissolved in the cleaning solution.

In addition, the concentration of condensed ammonium phosphate is preferably not less than 1% and not more than 40% relative to the total weight of the cleaning solution. This is because, when the concentration of condensed ammonium phosphate is lower than 1% by weight, the resist residue removal effect is poor.

On the other hand, when the concentration of condensed ammonium phosphate exceeds 40% by weight, there are difficulties in manufacture.

In addition, as described above, since the second wiring layer contains aluminum or the like, by adding a surfactant to this cleaning solution, it is possible to further suppress the dissolution of the aluminum or the like in the cleaning solution. In addition, by adding an activator, the effect of removing resist residues can be enhanced, and at the same time, the dissolution of the tungsten-containing buried metal film 14 can be suppressed.

Furthermore, considering that when the amount of the surfactant added to the cleaning solution is too much, the surfactant cannot be fully dissolved, and there are environmental problems such as waste liquid treatment, so the concentration of the surfactant is preferably below 500ppm.

In addition, as a resist residue removal method using this cleaning solution, the resist residue 22a can be removed by immersing the silicon substrate 2 in this cleaning solution or spraying this cleaning solution on the silicon substrate 2 .

Furthermore, the temperature of the cleaning solution at this time is preferably not less than 20°C and not more than 65°C. This is because, when the temperature of the cleaning solution is lower than 20°C, the removal effect of the resist residue 22a is poor. On the other hand, when the temperature of the cleaning solution is higher than 65°C, the second wiring layer containing aluminum or aluminum alloy 20 is easier to dissolve in the cleaning solution.

As described above, in the process of removing resist residues, if this cleaning solution is used, even if a borderless wiring is generated and a part of the surface of the buried metal film 14 is exposed, the cleaning solution will not affect the buried metal film 14 and the second wiring. Layer 20 also did not substantially dissolve. As a result, an increase in contact resistance between the second wiring layer 20 and the buried metal film 14 or disconnection can be prevented.

In this embodiment, the case where the resist residue in the step shown in FIG. 7 is removed using this cleaning solution has been described. However, in addition to this, in the process shown in FIG. 3 , when the resist pattern for forming the connection hole 10 is removed, the first wiring layer 6 attached to the side surface of the connection hole 10 and exposed on the bottom surface are removed. This cleaning solution can also be used when removing resist residues on the surface.

Even in this case, the resist residue can be reliably removed, and the cleaning solution does not substantially dissolve the first wiring layer 6 including aluminum or the like exposed from the bottom of the connection hole.

Example 2

The cleaning solution according to Example 2 of the present invention and a method of manufacturing a semiconductor device using the cleaning solution will be described. In addition, since the cleaning solution in this embodiment is the same as that described in the working example, its detailed description will be omitted.

First, referring to FIG. 10, an interlayer insulating film 26 made of a silicon oxide film or the like is formed on a silicon substrate 2 by CVD. A resist pattern (not shown) is formed on the interlayer insulating film 26 . Using the resist pattern as a mask, reactive ion etching is performed on the interlayer insulating film 26 to form a bit line contact hole 28 exposing the surface of the silicon substrate 102 . .

Next, referring to FIG. 11 , a polysilicon film (not shown) is formed on the interlayer insulating film 26 by CVD to cover the bit line contact hole 28 . By etching back the entire surface of the polysilicon film, only the polysilicon film is left in the bit line contact hole 28, whereby the buried film 30 is formed.

Next, referring to FIG. 12 , an underlying metal film 32 made of, for example, a titanium alloy such as titanium nitride or a tungsten alloy is formed by sputtering to cover the interlayer insulating film 26 and the buried film 30 . An upper layer metal film 34 containing tungsten or the like is formed on the lower layer metal film 32 by sputtering.

Next, referring to FIG. 13 , a resist pattern 36 is formed on the upper metal film 34 . Using the resist pattern 36 as a mask, reactive ion etching is performed on the upper metal film 34 and the lower metal film 32 to expose the surface of the interlayer insulating film 26 . Thus, the bit line 35 is formed.

It should be noted that the bit line 35 is assumed to be a borderless wiring due to misalignment when the resist pattern 36 is formed in this step. Therefore, a part of the upper surface of the buried film 30 is exposed.

Next, referring to FIG. 14, the oxygen-containing gas is turned into plasma, and the resist 36 is removed by exposing the silicon substrate 2 to the plasma gas. Resist residue 36 a adheres to the surface of the bit line 35 after the removal of the resist 36 and the exposed surface of the buried film 30 .

This resist residue 36a is removed using this cleaning solution. It was confirmed that the use of this cleaning solution can reliably remove resist residues even if a portion of the upper surface of the buried film 30 is exposed due to borderless wiring, and that the cleaning solution has no substantial effect on the buried film 30 formed of polysilicon. of the dissolution.

Therefore, as shown in FIG. 15 , an increase in contact resistance between the bit line 35 and the buried film 30 or disconnection can be prevented without substantially dissolving the buried film 30 by the cleaning solution.

In the first embodiment, the wiring material of the second wiring layer 20 contains aluminum or aluminum alloy, while in the present embodiment, the wiring material of the bit line 35 contains tungsten or a titanium alloy. Therefore, the components contained in the resist residue 36a and the resist residue 22a of Example 1 are different.

As a result, it was found that the lower limit temperature of the cleaning solution was higher than that of the cleaning solution in Example 1, that is, unless it was 40° C. or higher, the resist residue could not be sufficiently removed. On the other hand, it is also known that when the temperature of the cleaning solution is higher than 100° C., the cleaning solution evaporates quickly, making it difficult to use in practice.

Therefore, at this time, the temperature of the cleaning solution for removing the resist residue 36a is preferably not less than 40°C and not more than 100°C.

As described above, by using this cleaning solution in the resist residue removal step, even if the bit line 35 becomes a borderless wiring and a part of the surface of the buried film 30 is exposed, the resist residue 36a can be reliably removed and the cleaning solution There is no substantial dissolution of the buried film 30 and the bit line 35 . As a result, an increase in contact resistance between the bit line 35 and the buried film 30 or disconnection can be prevented.

In addition, in this embodiment, the process of removing the resist residue adhering when the bit line 35 is formed using this cleaning solution is described. In addition to this, for example, this cleaning solution can also be used in the step of removing resist residue adhering to the formation of the transfer gate of the transistor. In order to reduce the wiring resistance, the transfer gate uses tungsten like the bit line. Therefore, when the resist residue is removed, tungsten and polysilicon are exposed.

By using this cleaning solution, the resist residue 36a can be reliably removed without substantially dissolving the transmission gate containing tungsten and polysilicon in the cleaning solution.

Also, for example, in DRAM, in order to electrically connect transistors and capacitors in the memory cell area to elements formed in the peripheral circuit area, contact holes are formed in the interlayer insulating film formed on the substrate. The process of making the contact hole is simultaneously exposed from the surface of the bit line, the transmission gate, the silicon substrate and the cell plate of the capacitor.

In this process, the surface of the bit line and the transfer gate containing tungsten are exposed at the bottom of each contact hole, and the surface of the cell plate and the silicon substrate containing silicon are exposed. And, after the contact hole is formed, resist residues adhere to the surface.

When removing the resist residue, by using this cleaning solution, the resist residue can be reliably removed without substantially dissolving the bit line containing tungsten, the transmission gate, the cell plate containing silicon, and the silicon substrate. .

Example 3

The cleaning solution according to Example 3 of the present invention and a method of manufacturing a semiconductor device using the cleaning solution will be described. In addition, since the cleaning solution in this embodiment is the same as that described in Example 1, its description is omitted.

First, referring to FIG. 16, an underlying interlayer insulating film 38 made of a silicon oxide film or the like is formed on a silicon substrate 2 by the CVD method. Furthermore, an interlayer insulating film 40 is formed on the interlayer insulating film 38 by a CVD method or the like. A resist pattern (not shown) is formed on the interlayer insulating film 40 . Reactive ion etching is performed on the interlayer insulating film 40 using this resist pattern as a mask, whereby the first wiring groove 42 is formed.

Next, referring to FIG. 17, a first lower metal film (not shown) made of a titanium alloy is formed on the surface of the first wiring groove 42 and the interlayer insulating film 40 by, for example, sputtering. Next, a metal film (not shown) containing copper is formed by electroplating or sputtering. Then, the first lower metal film 44 and the first wiring layer 46 are formed in the first wiring trench by performing chemical mechanical polishing (CMP) on the metal film and the first lower metal film.

Next, referring to FIG. 18, an interlayer insulating film 48 is formed on the first wiring layer 46 and the interlayer insulating film 40 by the CVD method. A resist pattern 52 is formed on the interlayer insulating film 48 . Using the resist pattern 52 as a mask, reactive ion etching is performed on the interlayer insulating film 48 to form a connection hole 50 exposed from the surface of the first wiring layer 46 .

Next, referring to FIG. 19, the oxygen-containing gas is turned into plasma, and the resist 52 is removed by exposing the silicon substrate 2 to the plasma gas. Resist residue 52 a adheres to the side surfaces of the connection hole 50 and the exposed surface of the first wiring layer 46 after the removal of the resist 52 .

Next, referring to FIG. 20, the resist residue 52a is removed using this cleaning solution. It was confirmed that the resist residue 52 a could be reliably removed by using this cleaning solution, and the cleaning solution did not substantially dissolve the surface of the first wiring layer 46 exposed from the bottom of the connection hole 50 .

Next, referring to FIG. 21 , a resist pattern 54 is formed on the interlayer insulating film 48 . Reactive ion etching is performed on the interlayer insulating film 48 using the resist pattern 54 as a mask, whereby the second wiring groove 56 is formed. Next, referring to FIG. 22, the oxygen-containing gas is turned into plasma, and the resist 54 is removed by exposing the silicon substrate 2 to the plasma gas. Resist residue 54 a adheres to the side surface of the second wiring trench 56 after the removal of the resist 52 .

Next, referring to FIG. 23, the resist residue 54a is removed using this cleaning solution. It was confirmed that the resist residue 54 a can be reliably removed by pouring the cleaning solution into the connection hole 50 , and the cleaning solution does not substantially dissolve the surface of the first wiring layer 46 exposed from the bottom of the connection hole 50 .

Next, referring to FIG. 24 , a first layer containing titanium alloy is formed on the surface of the second wiring groove 56, the surface of the connection hole 50, the surface of the exposed second wiring layer 46, and the upper surface of the interlayer insulating film 48 by sputtering or the like. 2. The lower metal film 58. Next, a metal film containing copper is formed on the second lower layer metal film 58 by electroplating, sputtering, or the like.

Next, referring to FIG. 25 , the second wiring layer 60 is formed in the second wiring trench 56 by performing chemical mechanical polishing (CMP) on the metal film and the second lower metal film 58 .

Therefore, in a semiconductor device, a wiring structure having copper wiring called a dual damascene can be obtained.

As described above, it can be confirmed that when removing the resist residue 52a generated in the step shown in FIG. 19 and the resist residue 54a generated in the step shown in FIG. The resist residues 52a and 54a are removed without substantially dissolving the surface of the first wiring layer 46 exposed from the bottom of the connection hole 50 by the cleaning solution. Therefore, an increase in contact resistance between the first wiring layer 46 and the second wiring layer 60 or disconnection can be prevented.

In addition, in this embodiment, this cleaning solution is used to remove the resist residues 52a, 54a generated when the connection hole 50 or the second wiring groove 56 is formed. Alternatively, as shown in FIG. 17 , the cleaning solution may be used as a cleaning solution for cleaning the surface after the first wiring layer 46 is formed by chemical mechanical polishing. In particular, in this step, copper as a wiring material of the first wiring layer 46 and titanium alloy as a material of the first lower layer metal film 44 are exposed.

By using this cleaning solution, it is possible to effectively remove the contaminants generated by chemical mechanical polishing without dissolving such metals. In addition, this cleaning solution can also be used after performing chemical mechanical polishing at the time of forming the second wiring layer 60 .

The embodiment disclosed this time is an illustration in all respects, and the present invention is not limited thereto. The scope of the present invention is not the above-described content but the scope indicated by the claims, and all changes within the scope of the scope of the claims and equal content are included in the scope of the claims of the present invention.

Claims (15)

1. scavenging solution comprises condensed phosphoric acid ammonium as main component, as the abnormal composition and the acid of the urea or the urea of auxiliary, and it is characterized in that: hydrogen ion concentration is 10 ^-4More than the mol/l.

2. scavenging solution as claimed in claim 1 is characterized in that: above-mentioned hydrogen ion concentration is 10 ^-2Below the mol/l.

3. scavenging solution as claimed in claim 1 is characterized in that: above-mentioned acid is phosphoric acid or ortho-phosphoric acid.

4. scavenging solution as claimed in claim 1 is characterized in that: the polymerization degree of above-mentioned condensed phosphoric acid ammonium is more than 2 below 150.

5. scavenging solution as claimed in claim 1 is characterized in that: the abnormal composition of above-mentioned urea is biuret or triuret (triuret).

6. scavenging solution as claimed in claim 1 is characterized in that: the weight ratio of the abnormal composition of above-mentioned condensed phosphoric acid ammonium and above-mentioned urea or urea is 1: 1～10: 1.

7. scavenging solution as claimed in claim 1 is characterized in that: the concentration of above-mentioned condensed phosphoric acid ammonium with respect to the per-cent of the gross weight of scavenging solution more than 1% below 40%.

8. the manufacture method of a semiconductor device, it is characterized in that: have residue and remove operation, remove in the operation at this residue, use the condensed phosphoric acid ammonium comprise as main component, as the abnormal composition of the urea of auxiliary or urea and acid and hydrogen ion concentration 10 ^-4The above scavenging solution of mol/l is removed the lip-deep resist residue (22a, 36a, 52a, 54a) that remains in the conductive layer (14,20,30,35,46) that exposes at least on semiconducter substrate (2).

9. the manufacture method of semiconductor device as claimed in claim 8, it is characterized in that: above-mentioned conductive layer comprises tungsten or tungstenalloy (14).

10. the manufacture method of semiconductor device as claimed in claim 8, it is characterized in that: above-mentioned conductive layer comprises aluminum or aluminum alloy (20).

11. the manufacture method of semiconductor device as claimed in claim 8 is characterized in that: above-mentioned conductive layer comprises copper or copper alloy (46).

12. the manufacture method of semiconductor device as claimed in claim 8 is characterized in that: before residue is removed operation, have:

Go up the operation that forms above-mentioned conductive layer (46) in semiconducter substrate (2);

Go up to form insulating film (48) so that the operation that above-mentioned conductive layer (46) is covered in above-mentioned semiconducter substrate (2);

Go up the operation that forms resist figure (52) at above-mentioned insulating film (48);

Above-mentioned resist figure (52) is carried out etching, forms the operation of the connecting hole (50) on the surface expose above-mentioned conductive layer (46) thus above-mentioned insulating film (48) as mask; And

Remove the operation of above-mentioned resist figure (52),

Above-mentioned residue is removed operation and is right after after the operation of removing above-mentioned resist figure (52) and carries out.

13. the manufacture method of semiconductor device as claimed in claim 9 is the manufacture method of the semiconductor device of dependent claims 8, it is characterized in that: before residue is removed operation, have:

Go up the operation that forms insulating film (8) in semiconducter substrate (2);

In above-mentioned insulating film (8), form the operation of peristome (10);

Formation is imbedded electrical conductor (14) so that with the operation of above-mentioned peristome (10) landfill;

Go up the operation of the layer that becomes wiring layer (20) at above-mentioned insulating film (8);

Go up the operation that forms resist figure (22) at the layer that becomes above-mentioned wiring layer (20);

Above-mentioned resist figure (22) is carried out etching to form and the above-mentioned operation of imbedding the wiring layer (20) that electrical conductor (14) is connected as mask to the layer that becomes above-mentioned wiring layer (20); And

Remove the operation of above-mentioned resist figure (22),

Above-mentioned residue is removed operation and is right after after the operation of removing above-mentioned resist figure (22) and carries out, and above-mentioned conductive layer (20,14) comprises above-mentioned wiring layer (20) and the above-mentioned electrical conductor (14) of imbedding.

14. the manufacture method of semiconductor device as claimed in claim 13 is characterized in that: the above-mentioned electrical conductor of imbedding comprises tungsten (14),

Above-mentioned wiring layer comprises aluminum or aluminum alloy (16).

15. the manufacture method of semiconductor device as claimed in claim 10 is characterized in that: the hydrogen ion concentration of above-mentioned scavenging solution is 10 ^-2Below the mol/l.

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