JP2001326198A - Polished composition for copper-based metal, polished composition for copper diffusion preventing material and manufacturing method of semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polished composition for a copper-based metal, which increases the polishing rate of copper (Cu) or a copper alloy (Cu alloy) and also enables increase in the selection ratio of polishing of the polishing composition to a copper diffusion preventing material such as tantalum. SOLUTION: A polished composition for a copper-based metal contain a water-soluble organic acid, which reacts with copper, is substantially insoluble in water and produces a copper complex which is mechanically more brittle than copper, at least one polished abrasive grain which is selected from among aluminas, including a Q-alumina phase or a boehmite phase, an oxidizing agent and water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polishing composition for a copper-based metal, a polishing composition for a copper diffusion preventing material, and a method for manufacturing a semiconductor device.

[0002]

2. Description of the Related Art In forming a wiring layer, which is one of the manufacturing steps of a semiconductor device, an etch-back technique is employed for the purpose of eliminating a step on a surface. In this etch-back technique, a wiring-shaped groove is formed in an insulating film on a semiconductor substrate, a Cu film is deposited on the insulating film including the groove, and the Cu film is polished using a polishing apparatus and a polishing composition. This is a method of forming a buried wiring layer by processing and leaving a Cu film only in the trench.

[0003] Incidentally, as the polishing composition, those containing ferric nitrate and γ-alumina abrasive grains, those containing ammonia, potassium cyanide and alumina abrasive grains, or those containing nitric acid, BTA and alumina abrasive grains have hitherto been used. Are known.

However, a groove is formed in an interlayer insulating film made of SiO ₂ on a semiconductor substrate, and a copper diffusion preventing film such as TaN is formed on the entire surface of the interlayer insulating film including the groove. After a wiring material film made of copper or a copper alloy is formed so as to sufficiently fill the groove, the wiring material film is polished using the polishing composition, and further, the copper on the insulating film excluding the groove is removed. When the etch back for removing the diffusion prevention film is performed, the following problem occurs.

(1) The polishing rate for the wiring material film made of copper or copper alloy and the copper diffusion preventing film is low.

(2) When polishing the wiring material film and further polishing the copper diffusion preventing film on the interlayer insulating film excluding the groove, the polishing rate of the wiring material film is higher than that of the copper diffusion preventing film. That is, since the polishing selection ratio of the wiring material film / copper diffusion preventing film is large, dishing in which a recess is formed on the surface of the buried wiring layer made of copper or copper alloy embedded in the groove after polishing the copper diffusion preventing film proceeds. .

[0007]

SUMMARY OF THE INVENTION The present invention relates to a copper (C) coating whose base is coated on a copper diffusion preventing film such as a titanium nitride film.
In order to provide a polishing composition for a copper-based metal, which can increase the polishing rate of copper or a copper alloy in the polishing of u) or a copper alloy (Cu alloy) and increase the polishing selectivity with the copper diffusion preventing material. Is what you do.

According to the present invention, in the polishing of a copper diffusion preventing film after polishing of copper or copper alloy, the polishing selectivity between the copper or copper alloy and the copper diffusion preventing film material is reduced to suppress the polishing of copper or copper alloy. It is an object of the present invention to provide a polishing composition for a diffusion preventing metal which can polish a copper diffusion preventing film material.

According to the present invention, at least one burying member selected from a groove and an opening is formed in an insulating film on a semiconductor substrate, and copper (Cu) or copper alloy (Cu) is formed on the insulating film.
After forming a wiring material film made of an alloy, it is possible to etch back in a short time by polishing, and to form a conductive member such as a high-precision buried wiring layer whose periphery is covered except for the surface with a copper diffusion preventing film. It is intended to provide a possible method of manufacturing a semiconductor device.

Further, according to the present invention, a groove and an opening are formed in an insulating film on a semiconductor substrate, and a wiring material film made of copper (Cu) or a copper alloy (Cu alloy) formed on the insulating film is formed. An object of the present invention is to provide a method of manufacturing a semiconductor device capable of forming a wiring layer having a high-precision dual damascene structure, which can be etched back in a short time by subsequent polishing and has a high-precision dual damascene structure whose periphery except for the surface is covered with a copper diffusion preventing film. Is what you do.

Further, the present invention provides a method of manufacturing a semiconductor device capable of forming a high-precision multi-layered wiring mainly composed of copper, the periphery of which is covered with a copper diffusion preventing film except for the surface by short-time etch back. It is something to offer.

[0012]

SUMMARY OF THE INVENTION A polishing composition for a copper-based metal according to the present invention is an aqueous solution which reacts with copper to form a copper complex which is substantially insoluble in water and mechanically more brittle than copper. Organic acid, and at least one abrasive grain selected from alumina containing a θ-alumina phase or a boehmite phase, and an oxidizing agent and water mixed at a weight ratio of 3 to 20 times with respect to the organic acid. It is characterized by containing.

The polishing composition for a copper diffusion preventing material according to the present invention comprises a water-soluble organic acid which reacts with copper to form a copper complex which is substantially insoluble in water and which is more brittle than copper. , Θ
-Containing at least one abrasive grain selected from alumina and bayerite containing an alumina phase or a boehmite phase, and an oxidizing agent and water mixed in a weight ratio of 3 to 20 times with respect to the organic acid. It is a feature.

In the method of manufacturing a semiconductor device according to the present invention, at least one embedding member selected from a groove corresponding to a shape of a wiring layer and an opening corresponding to a shape of a via fill is formed in an insulating film on a semiconductor substrate. Forming a copper diffusion preventing film on the insulating film including the inner surface of the embedding member; forming a wiring material film made of copper or a copper alloy on the copper diffusion preventing film; Polishing the wiring material film with a polishing composition for a base metal until at least the copper diffusion preventing film portion on the insulating film excluding the embedding member is exposed; and Polishing at least the copper diffusion preventing film portion on the insulating film excluding the embedding member using a polishing composition, whereby the periphery excluding the surface inside the embedding member has the copper diffusion. It is characterized in that it comprises a; forming at least one conductive member selected from the wiring layers and via fill covered with sealing film.

Another method of manufacturing a semiconductor device according to the present invention is a method of manufacturing a semiconductor device, comprising the steps of: forming a groove in an insulating film on a semiconductor substrate in a shape corresponding to a wiring layer; Forming an opening reaching the surface;
Forming a copper diffusion prevention film on the insulating film including the inner surface of the groove and the opening; forming a wiring material film made of copper or a copper alloy on the copper diffusion prevention film; Polishing the wiring material film using a polishing composition for metal until the copper diffusion preventing film portion on the insulating film excluding at least the grooves and openings is exposed; and for the copper diffusion preventing material having the above-described composition. Polishing the copper diffusion prevention film portion on the insulating film except for at least the groove and the opening using a polishing composition, whereby the periphery except the surface in the opening and the groove is the copper diffusion prevention film. Forming a covered wiring having a dual damascene structure.

In still another method of manufacturing a semiconductor device according to the present invention, a step of forming a first opening having a shape corresponding to at least a first via fill in a first insulating film on a semiconductor substrate;
Forming a first copper diffusion preventing film on the first insulating film including an inner surface of the first opening; forming a first wiring material film made of copper or a copper alloy on the first copper diffusion preventing film; Step: using the polishing composition for a copper-based metal having the above-described composition, changing the first wiring material film until the first copper diffusion preventing film portion on the first insulating film excluding at least the first opening is exposed. Polishing step: using the polishing composition for a copper diffusion prevention material having the above-described composition, polishing at least the copper diffusion prevention film portion on the first insulating film except for the first opening, thereby forming the first opening. Forming a first via fill whose periphery except the surface is covered with the first copper diffusion preventing film; forming a second insulating film on the first insulating film including the first via fill; 2 At least reaches the first via fill in the insulating film Forming a second opening having a shape corresponding to 2 via fill; forming a second copper diffusion preventing film on the second insulating film including the second opening; forming a second copper diffusion preventing film on the second copper diffusion preventing film; Forming a second wiring material film made of copper or a copper alloy; using a polishing composition for a copper-based metal having the above-described composition, forming the second wiring material film on the second insulating film except for the second opening; Polishing until the second copper diffusion preventing film portion is exposed; and the copper diffusion on the second insulating film except for the second opening using the polishing composition for a copper diffusion preventing material having the above-described composition. Polishing the prevention film portion, thereby forming a second via fill in which the periphery except the surface is covered with the second copper diffusion prevention film in the second opening. .

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the polishing composition for a copper-based metal according to the present invention will be described in detail.

The copper-based metal polishing composition comprises a water-soluble organic acid which reacts with copper to form a copper complex which is substantially insoluble in water and which is more fragile than copper, and θ-alumina. At least one abrasive selected from alumina containing a phase or a boehmite phase, an oxidizing agent and water mixed in a weight ratio of 20 to 50 times with respect to the organic acid.

The organic acid may be substantially insoluble in water by reacting with copper hydrate generated by the oxidizing agent when the polishing composition is brought into contact with copper or a copper alloy,
It has an effect of forming a copper complex which is more fragile than Cu. Examples of such organic acids include 2-quinoline carboxylic acid (quinaldic acid), 2-pyridine carboxylic acid,
6-pyridinecarboxylic acid, quinone and the like can be mentioned.

The organic acid is contained in the polishing composition in an amount of 0.1%.
Preferably, it is contained in an amount of at least% by weight. When the content of the organic acid is less than 0.1% by weight, it is difficult to sufficiently generate a copper complex that is more mechanically weaker than copper on the surface of Cu or a Cu alloy. As a result, it becomes difficult to sufficiently increase the polishing rate of Cu or Cu alloy during polishing. More preferably, the content of the organic acid is 0.3 to 1.
2% by weight.

Alumina containing the θ-alumina phase constituting the abrasive grains is, for example, ammonium doughonite (N
It is produced by thermally decomposing H ₄ AlCo ₃ (OH) ₂ ) at 1300 ° C. FIG. 1 shows an X-ray diffraction diagram of alumina containing such a θ-alumina phase.

Alumina containing a boehmite phase constituting the abrasive grains is produced by hydrothermal synthesis of bayerite.

Preferably, the abrasive grains have an average primary particle size of 0.02 to 0.1 μm and have a spherical or spherical shape. When a polishing treatment is performed on Cu or a Cu alloy using a polishing composition containing such polishing abrasive grains,
Damage to the polishing surface of Cu or Cu alloy can be suppressed.

The above-mentioned polishing abrasive is used in the above-mentioned polishing composition in an amount of 0.1%.
It is preferably contained in an amount of 8 to 20% by weight. When the content of the abrasive grains is less than 0.8% by weight, it is difficult to sufficiently achieve the effect. On the other hand, when the content of the abrasive grains exceeds 20% by weight, the handling becomes difficult, for example, the viscosity of the polishing composition increases. A more preferable content of the abrasive grains is 0.8 to 3% by weight.

The polishing abrasive grains are allowed to further contain colloidal alumina.

The oxidizing agent has a function of forming a hydrate of copper when the polishing composition is brought into contact with copper or a copper alloy. As such an oxidizing agent, for example, an oxidizing agent such as hydrogen peroxide (H ₂ O ₂ ) or sodium hypochlorite (NaClO) can be used.

If the content of the oxidizing agent is less than three times the weight of the organic acid, it becomes difficult to sufficiently promote the formation of a copper complex on the surface of Cu or a Cu alloy.
On the other hand, if the content of the oxidizing agent exceeds 20 times the weight of the organic acid by weight, the polishing rate of copper or copper alloy may be reduced.

The polishing composition for a copper-based metal according to the present invention further comprises one carboxyl group and one hydroxyl group.
It is allowed to contain another organic acid. This other organic acid has an effect of promoting the formation of copper hydrate by the oxidizing agent. Such other organic acids include, for example, lactic acid, tartaric acid, mandelic acid, malic acid and the like, and these can be used in the form of one kind or a mixture of two or more kinds. Lactic acid is particularly preferably used as the second organic acid.

The other organic acid may be present in the polishing composition in an amount of 20 to an organic acid such as the 2-quinoline carboxylic acid.
Preferably, it is contained in an amount of up to 250% by weight. When the content of the another organic acid is less than 20% by weight, it is difficult to sufficiently exert the effect of promoting the formation of copper hydrate by the oxidizing agent. On the other hand, when the content of the another organic acid is 2
If it exceeds 50% by weight, the copper thin film may be etched, and pattern formation may not be possible. More preferably, the content of the another organic acid is 40 to 20 with respect to the organic acid.
0% by weight.

The polishing composition for a copper-based metal according to the present invention permits the addition of a nonionic, zwitterionic, anionic or cationic surfactant. The polishing composition further containing such a surfactant makes it possible to enhance selective polishing of Cu or a Cu alloy and an insulating film such as a SiN film and SiO ₂ as described later.

Examples of the nonionic surfactant include polyethylene glycol phenyl ether and ethylene glycol fatty acid ester.

As the zwitterionic surfactant, for example, imidazoribetaine and the like can be mentioned.

Examples of the anionic surfactant include sodium dodecyl sulfate and ammonium dodecyl sulfate.

The cationic surfactant includes, for example, stearin trimethylammonium chloride.

The above-mentioned surfactants may be used in the form of a mixture of two or more.

The above-mentioned surfactant is contained in the above-mentioned polishing composition.
It is preferable to add at least mol / L. If the amount of the surfactant is less than 1 mol / L, it becomes difficult to enhance the selective polishing of Cu or a Cu alloy and an insulating film such as SiO ₂ during polishing. A more preferred amount of the surfactant is in the range of 10 to 100 mol / L.

The polishing composition for a copper-based metal according to the present invention comprises:
Further, it is permitted to contain a dispersant for the abrasive grains.
As the dispersant, for example, polyvinylpyrrolidone (P
VP) and the like.

Next, the polishing composition for a copper diffusion preventing material according to the present invention will be described in detail.

The polishing composition for a copper diffusion preventing material comprises a water-soluble organic acid which reacts with copper to form a copper complex which is substantially insoluble in water and which is mechanically more brittle than copper; It contains at least one abrasive grain selected from alumina containing alumina phase or boehmite phase and bayerite, and an oxidizing agent and water mixed in a weight ratio of 20 to 50 times with respect to the organic acid.

The organic acid is substantially insoluble in water by reacting with copper hydrate generated by the oxidizing agent when the polishing composition is brought into contact with copper or a copper alloy,
It has an effect of forming a copper complex which is more fragile than Cu. Examples of such organic acids include 2-quinoline carboxylic acid (quinaldic acid), 2-pyridine carboxylic acid,
6-pyridinecarboxylic acid, quinone and the like can be mentioned.

The organic acid is added to the polishing composition in an amount of 0.1%.
Preferably, it is contained in an amount of at least% by weight.

The abrasive grains preferably have an average primary particle size of 0.02 to 0.1 μm and have a spherical or spherical shape.

The above-mentioned polishing abrasive is used in the above-mentioned polishing composition in an amount of 0.1%.
It is preferably contained in an amount of 8 to 20% by weight. When the content of the abrasive grains is less than 0.8% by weight, it is difficult to sufficiently achieve the effect. On the other hand, when the content of the abrasive grains exceeds 20% by weight, the handling becomes difficult, for example, the viscosity of the polishing composition increases. A more preferable content of the abrasive grains is 0.8 to 3% by weight.

The abrasive grains are allowed to further contain colloidal alumina.

As the oxidizing agent, an oxidizing agent such as hydrogen peroxide (H ₂ O ₂ ) or sodium hypochlorite (NaClO) can be used.

When the content of the oxidizing agent is less than three times the weight of the organic acid by weight, the polishing rate of Cu or Cu alloy exposed together with the copper diffusion preventing film is reduced, and the copper diffusion preventing film is removed. It becomes difficult to increase the polishing rate. on the other hand,
The content of the oxidizing agent is 2% by weight with respect to the organic acid.
If it exceeds 0 times, Cu expressed together with the copper diffusion preventing film
Alternatively, the formation of a copper complex on the Cu alloy surface may be excessively advanced.

The polishing composition for a copper diffusion preventing material according to the present invention is allowed to further contain another organic acid having one carboxyl group and one hydroxyl group. This other organic acid has an effect of promoting the formation of copper hydrate by the oxidizing agent. Such other organic acids include, for example, lactic acid, tartaric acid, mandelic acid, malic acid and the like, and these can be used in the form of one kind or a mixture of two or more kinds. Lactic acid is particularly preferably used as the second organic acid.

The another organic acid may be present in the polishing composition in an amount of 20 to an organic acid such as the 2-quinoline carboxylic acid.
Preferably, it is contained in an amount of up to 250% by weight. More preferably, the content of the another organic acid is 40 to the organic acid.
~ 200% by weight.

The polishing composition for a copper diffusion preventing material according to the present invention further comprises a nonionic, amphoteric, anionic or cationic surfactant similarly to the above-mentioned polishing composition for a copper-based metal. Allow to be added.

The above-mentioned surfactant is contained in the above-mentioned polishing composition.
Mol / L or more, more preferably 10 to 100 mol / L.

The polishing composition for a copper diffusion preventing material according to the present invention is allowed to further contain a dispersant for the abrasive grains. Examples of the dispersant include polyvinylpyrrolidone (PVP).

For example, a concave portion is formed in an insulating film on a substrate using the polishing composition for a copper-based metal and the polishing composition for a copper diffusion preventing material according to the present invention. Forming a copper diffusion preventing film such as a TaN) film;
Further, in order to form a Cu film or a Cu alloy film and polish the Cu film or the Cu alloy film and the copper diffusion preventing film, a polishing apparatus shown in FIG. 2 is used. That is, the turntable 1 is covered with a polishing pad 2 made of, for example, a cloth or a polyurethane foam having closed cells. The supply pipe 3 for supplying the polishing composition is:
It is arranged above the polishing pad 2. A substrate holder 5 having a support shaft 4 on its upper surface is arranged above the polishing pad 2 so as to be vertically movable and rotatable.

In such a polishing apparatus, the substrate 6 is held by the holder 5 so that the polishing surface (eg, Cu film) of the polishing pad 2 faces the polishing pad 2. The substrate 6 is given a desired weight toward the polishing pad 2 by the support shaft 4 while the support shaft 4 is being supplied, and the holder 5 and the turntable 1 are further rotated in the same direction. The Cu film is polished.

The above-described polishing composition for a copper-based metal according to the present invention comprises a water-soluble organic acid which reacts with copper to form a copper complex which is hardly soluble in water and which is more brittle than copper. , Θ-
Since at least one abrasive grain selected from alumina containing alumina phase or boehmite phase, and an oxidizing agent and water mixed in a weight ratio of 3 to 20 times with respect to the organic acid, and water, the base material is made of titanium nitride ( Cu or a Cu alloy coated on a copper diffusion preventing film such as a TaN) film does not dissolve the Cu or the like at all during immersion, and can polish Cu or a Cu alloy at a practical rate during polishing. The polishing selectivity with the copper diffusion preventing material can be increased. Here, the practical polishing rate means that the polishing rate is 10 times or more that in the case of using a polishing composition containing only conventional polishing abrasive grains.

Further, the polishing composition for a copper diffusion preventing material according to the present invention comprises a water-soluble organic acid which reacts with copper to form a copper complex which is hardly soluble in water and which is more brittle than copper. , Θ-
At least one abrasive grain selected from alumina and bayerite containing an alumina phase or a boehmite phase, and containing an oxidizing agent and water mixed in a weight ratio of 20 to 50 times with respect to the organic acid, copper or In polishing a copper diffusion prevention film such as a titanium nitride (TaN) film after polishing a copper alloy, the polishing selectivity between the copper or copper alloy and the copper diffusion prevention film material is reduced to suppress polishing of the copper or copper alloy. Then, the copper diffusion preventing film material can be polished.

That is, as shown in FIG. 3A, for example, an insulating film 12 is formed on a substrate 11, an opening (via hole) 13 reaching the substrate 11 is formed in the insulating film 12, and A copper diffusion preventing film 14 such as Ta is formed on the insulating film 12 including the inner surface, and a Cu film 15 is further formed on the copper diffusion preventing film 14 with the via hole 13.
It is formed to fill the inside.

Then, the substrate 11 shown in FIG. 3A is placed on the substrate holder 5 of the polishing apparatus by using the polishing apparatus shown in FIG.
At least one polishing selected from an organic acid (eg, 2-quinoline carboxylic acid), an oxidizing agent (eg, hydrogen peroxide), an alumina including a θ-alumina phase or a boehmite phase. A polishing composition for a copper-based metal containing an abrasive, water and an oxidizing agent mixed with the organic acid in a weight ratio of 3 to 20 times is supplied from a supply pipe 3 to the polishing pad 2 so that Cu When the film 15 comes into contact with the polishing composition for a copper-based metal, an oxidizing agent in the composition reacts with copper in the presence of water to react with copper hydrate (Cu
Ions). At this time, the organic acid (for example, 2-quinolinecarboxylic acid) in the polishing composition reacts with the Cu hydrate (Cu ion) according to the reaction formula shown in the following Chemical Formula 1 to react with the Cu hydrate (Cu ion). As shown in (), a copper complex layer 16 is formed on the surface of the Cu film 15.

[0058]

Embedded image

Next, the substrate 11 shown in FIG. 3A is held in the substrate holder 5 of the polishing apparatus, and the supply of the copper-based metal polishing composition from the supply pipe 3 to the polishing pad 2 is continued. A predetermined load is applied to the polishing pad 2 by the support shaft 4 on the substrate while rotating the holder 5 and the turntable 1 in the same direction. At this time, the copper complex layer 16 formed on the surface of the Cu film 15 by the above reaction formula is not dissolved in water, but is more fragile than Cu, and therefore contains the polishing abrasive grains present in the polishing pad 2. As shown in FIG. 3B, the copper complex layer 16 corresponding to the convex portion of the Cu film 15 is mechanically polished by the copper-based metal polishing composition.

The polishing of the Cu film 15 is continued by using the polishing apparatus and the polishing composition for a copper-based metal until the portion of the copper diffusion preventing film 13 corresponding to the surface of the insulating film is exposed. ), Cu17 remains in the via hole 13.

After such a step, a water-soluble organic compound which reacts with copper in place of the polishing composition for a copper-based metal to form a copper complex which is substantially insoluble in water and mechanically more brittle than copper. the acid and θ- alumina phases or Bareru twisted alumina and bayerite containing boehmite phase at least one abrasive grains and 20 to 50 times distribution <br/> engaged by oxidizing agent in a weight ratio with respect to the organic acid A polishing composition for a copper diffusion preventing material containing water, and a position on the surface of the insulating film 12 while suppressing polishing of Cu 17 in the via hole 13 by polishing the copper diffusion preventing film using the polishing apparatus described above. The portion of the copper diffusion preventing film 14 to be removed can be removed. As a result, as shown in FIG. 3D, the copper diffusion preventing film 14 remains in the via hole 13, and the surface and the surface of the insulating film 12 are formed in the via hole 13 covered with the copper diffusion preventing film 14. A via fill 18 made of a uniform Cu can be formed.

Therefore, the polishing composition for a copper-based metal according to the present invention has a high polishing rate for a Cu or Cu alloy film and a high polishing selectivity with a copper diffusion preventing material, so that the film can be etched in a short time. In addition to the backing, it is possible to easily confirm the polishing completion timing of the coating on the copper diffusion preventing film located on the surface of the insulating film.

When polishing of the Cu or Cu alloy film on the copper diffusion preventing film portion located on the surface of the insulating film is completed, Cu or Cu and the copper diffusion preventing film are used instead of the polishing composition for a copper-based metal. Polishing the copper diffusion preventing film exposed on the insulating film using a polishing composition for a copper diffusion preventing material having a characteristic of a small polishing selectivity with a material, the Cu exposed on the surface together with the copper diffusion preventing film is polished. Alternatively, the copper diffusion preventing film portion located on the surface of the insulating film can be removed while suppressing polishing of a Cu alloy (wiring or via fill). As a result, Cu or C whose periphery is covered with the copper diffusion prevention film
A recess is formed in the wiring or via fill made of a u alloy,
So-called dishing can be prevented.

The polishing composition for a copper-based metal according to the present invention does not dissolve the Cu or the like when immersed in Cu or a Cu alloy. Therefore, the etching of Cu is performed by the supply timing of the polishing composition in the polishing process. Problems such as a change in the amount can be avoided, and the operation can be performed easily.

Further, when the Cu film or Cu alloy film is polished by the polishing apparatus shown in FIG. 2 with the polishing composition for a copper-based metal, the Cu film or Cu alloy film is applied to the polishing pad 2 by a predetermined load. Polishing is performed only during the contact (sliding contact). When the polishing pad separates from the Cu film, polishing is immediately stopped. Therefore, it is possible to prevent so-called over-etching in which the Cu film or the Cu alloy film is further etched after the polishing treatment.

In the polishing composition for a copper-based metal according to the present invention, by adding a nonionic, zwitterionic, anionic or cationic surfactant, Cu or Cu alloy and SiO It is possible to increase the selective polishing ratio with the insulating film such as ₂ .

Next, a method of manufacturing a semiconductor device according to the present invention will be described.

First, at least one embedding member selected from a groove corresponding to the shape of a wiring layer and an opening corresponding to the shape of a via fill is formed in an insulating film on a semiconductor substrate. Subsequently, a copper diffusion preventing film is formed on the insulating film including the inner surface of the embedding member. After forming a wiring material film made of copper or a copper alloy on the copper diffusion prevention film,
The wiring material film is polished by using the copper-based metal polishing composition having the composition described above until the copper diffusion preventing film portion on the insulating film excluding the burying member is exposed. Next, the copper diffusion preventing film portion on the insulating film excluding the embedding member is polished by using the copper diffusion preventing material polishing composition having the above-described composition instead of the copper-based metal polishing composition, Thus, at least one conductive member selected from a wiring layer and a via fill whose periphery except the surface is covered with the copper diffusion preventing film is formed in the embedding member to manufacture a semiconductor device.

As the insulating film, for example, a silicon oxide film, a boron-doped glass film (BPSG film), a phosphorus-doped glass film (PSG film), or the like can be used. This insulating film allows its surface to be covered with an insulating polishing stopper film made of silicon nitride, carbon, alumina, boron nitride, diamond, or the like.

It is preferable that the insulating film is made of an insulating material having a relative dielectric constant of 3.5 or less. Examples of the insulating material having this relative dielectric constant include SiOF, organic spin-on-glass, polyimide, fluorinated polyimide, polytetrafluoroethylene, fluorinated polyallyl ether, and fluorinated parelin. By using an insulating film having such a relative dielectric constant, it is possible to increase the signal propagation speed of a wiring layer made of copper or a copper alloy embedded in the insulating film.

The copper diffusion preventing film is made of, for example, TaN, Ta
Nb, W, WN, TaN, TaSiN, Ta, Co, Z
It is made of one or more layers selected from r, ZrN and CuTa alloy. Such a copper diffusion prevention film is composed of 1
Preferably, it has a thickness of 5 to 50 nm.

As the Cu alloy, for example, Cu—Si
Alloy, Cu-Al alloy, Cu-Si-Al alloy, Cu-
An Ag alloy or the like can be used.

The wiring material film made of Cu or Cu alloy is formed by sputter deposition, vacuum deposition, electroless plating, or the like. Specifically, copper or a copper alloy is deposited by a sputtering method or a CVD method, and further subjected to electroless copper plating to form a wiring material film made of copper or a copper alloy.

The polishing treatment using the polishing composition for a copper-based metal and the polishing composition for a copper diffusion preventing material is carried out, for example, by using the polishing apparatus shown in FIG.

In the polishing process using the polishing apparatus shown in FIG. 2, the load applied to the polishing pad by the substrate held by the substrate holder is appropriately selected depending on the composition of the polishing composition. For example, the load is 50 to 1000 g / cm ² . Is preferred.

In the method of manufacturing a semiconductor device according to the present invention described above, first, at least one embedding selected from a groove corresponding to the shape of a wiring layer and an opening corresponding to the shape of a via fill in an insulating film on a semiconductor substrate. A copper diffusion preventing film is formed on the insulating film including the inner surface of the embedding member, and a wiring material film made of copper or a copper alloy is formed on the copper diffusion preventing film. Subsequently, a water-soluble organic acid that reacts with copper to form a copper complex that is hardly soluble in water and mechanically weaker than copper, and at least one selected from alumina containing a θ-alumina phase or a boehmite phase The polishing composition for a copper-based metal described above containing one abrasive grain, an oxidizing agent that is mixed 3 to 20 times by weight with respect to the organic acid, and water, for example, the polishing shown in FIG. 2 described above. The wiring material film is polished using an apparatus until the copper diffusion preventing film portion on the insulating film excluding the embedding member is exposed. As described above, the polishing composition for a copper-based metal does not dissolve the Cu film or the Cu alloy film at all when the Cu film or the Cu alloy film is immersed, and the Cu or Cu alloy has a practical speed at the time of polishing. Can be polished.

Further, the polishing composition for a copper-based metal is characterized in that the polishing selection ratio with the copper diffusion preventing material is high. Therefore, it is possible to etch back the wiring material film in a short time, and it is possible to easily confirm the polishing end time of the wiring material film on the copper diffusion preventing film portion located on the surface of the insulating film.

At the end of the polishing of the wiring material film of Cu or Cu alloy on the copper diffusion preventing film portion located on the surface of the insulating film, C is replaced with the polishing composition for copper-based metal.
The copper diffusion preventing film exposed on the insulating film is polished using a polishing composition for a copper diffusion preventing material having a characteristic of a small polishing selectivity between u or Cu and a copper diffusion preventing film material, whereby the copper diffusion is reduced. The copper diffusion prevention film portion located on the insulating film surface can be removed while suppressing the polishing of the wiring material film exposed on the surface together with the prevention film. As a result, it is possible to prevent dishing in which a recess is formed in at least one buried conductive member selected from a wiring layer made of Cu or a Cu alloy and a via fill exposed on the surface together with the copper diffusion preventing film.

Therefore, at least one buried conductive member selected from a wiring layer and a via fill is formed in at least one buried member selected from the groove and the opening surrounded by the copper diffusion preventing film while suppressing dishing. Accordingly, it is possible to manufacture a semiconductor device capable of preventing Cu as a wiring material from diffusing into the insulating film with the copper diffusion preventing film and preventing contamination of the semiconductor substrate with Cu.

Further, if a polishing composition for a copper-based metal further containing a nonionic, zwitterionic, anionic, or cationic surfactant is used, Cu or a Cu alloy is used in the etch-back step. Wiring material film and SiO
Selective polishing with an insulating film such as ₂ can be improved. As a result, thinning of the underlying insulating film can be suppressed, and a semiconductor device with high withstand voltage can be manufactured. In addition, by using the polishing composition containing such a surfactant, it is possible to easily remove fine wiring materials and contaminants such as organic substances remaining on the insulating film in cleaning after the etch-back step. Will be possible. Therefore, it is possible to manufacture a semiconductor device having a clean surface from which organic substances and residual wiring materials on the surface of the insulating film are removed.

Next, a method of manufacturing a semiconductor device having a wiring having a dual damascene structure according to the present invention will be described.

First, a groove having a shape corresponding to a wiring layer is formed in an insulating film on a semiconductor substrate, and an opening reaching the surface of the semiconductor substrate is formed in the interlayer insulating film located at a part of the bottom of the groove. Subsequently, a copper diffusion preventing film is formed on the insulating film including the inner surface of the groove and the opening. After forming a wiring material film made of copper or a copper alloy on the copper diffusion preventing film, the wiring material film is subjected to the insulation except for the grooves and openings using a polishing composition for a copper-based metal having the above-described composition. Polishing is performed until the copper diffusion preventing film portion on the film is exposed.
Then, polishing the copper diffusion prevention film portion on the insulating film except for the grooves and openings using the copper diffusion prevention material polishing composition of the above composition instead of the copper-based metal polishing composition, As a result, a wiring having a dual damascene structure in which the periphery except the surface is covered with the copper diffusion preventing film in the opening and the groove is formed, thereby manufacturing a semiconductor device.

On the surface of the semiconductor substrate where the opening is located, a diffusion layer of the same conductivity type as the substrate or a conductivity type opposite to the substrate is allowed to be formed. The former diffusion layer can be used as a substrate bias, and the latter diffusion layer can be used as a wiring layer.

As the insulating film, for example, a silicon oxide film, a boron-doped glass film (BPSG film), a phosphorus-doped glass film (PSG film), or the like can be used. This insulating film allows its surface to be covered with an insulating polishing stopper film made of silicon nitride, carbon, alumina, boron nitride, diamond, or the like.

The insulating film has the above-mentioned relative dielectric constant of 3.5.
It is preferably made from the following insulating materials: By using an insulating film having such a relative dielectric constant, it is possible to increase the signal propagation speed of a wiring layer having a dual damascene structure made of copper or a copper alloy embedded in the insulating film.

To form a groove and an opening in the insulating film, for example, (1) After forming a groove corresponding to the shape of a wiring layer in the insulating film by an etching technique, a part of the groove bottom is selected. A method of forming an opening reaching the surface of the semiconductor substrate by selective etching; or (2) forming a hole in the insulating film by a selective etching technique from the bottom to the depth of the groove whose thickness from the bottom to the surface of the substrate will be described later. And then selectively etching the insulating film including the hole to form a groove corresponding to the shape of the wiring layer and removing the insulating film portion at the bottom of the hole. You.

The copper diffusion preventing film is made of, for example, TaN, Ta
Nb, W, WN, TaN, TaSiN, Ta, Co, C
It is made of one or more layers selected from o, Zr, ZrN and CuTa alloy. Such a copper diffusion barrier film preferably has a thickness of 15 to 50 nm.

As the Cu alloy, for example, Cu—Si
Alloy, Cu-Al alloy, Cu-Si-Al alloy, Cu-
An Ag alloy or the like can be used.

The wiring material film made of Cu or Cu alloy is formed by sputter deposition, vacuum deposition, electroless plating, or the like. Specifically, copper or a copper alloy is deposited by a sputtering method or a CVD method, and further subjected to electroless copper plating to form a wiring material film made of copper or a copper alloy.

The polishing treatment with the polishing composition is performed, for example, by using the polishing apparatus shown in FIG.

In the polishing process using the polishing apparatus shown in FIG. 2, the load applied to the polishing pad by the substrate held by the substrate holder is appropriately selected depending on the composition of the polishing composition. Preferably it is ² .

According to the present invention described above, the periphery of the trench and the opening of the insulating film is covered with the copper diffusion preventing film, so that contamination of the semiconductor substrate by Cu can be prevented and dishing can be suppressed. A semiconductor device having a wiring layer having a highly accurate dual damascene structure can be manufactured.

Next, a method of manufacturing a semiconductor device having a multilayer wiring structure according to the present invention will be described.

First, a first opening having a shape corresponding to at least a first via fill is formed in a first insulating film on a semiconductor substrate. A first copper diffusion preventing film is formed on the first insulating film including the inner surface of the first opening. Subsequently, after forming a first wiring material film made of copper or a copper alloy on the first copper diffusion preventing film, the first wiring material film is formed by using the copper-based metal polishing composition having the above-described composition. Polishing is performed until the first copper diffusion preventing film portion on the first insulating film excluding the first opening is exposed. Subsequently, the copper diffusion preventing film portion on the first insulating film excluding the first opening is polished by using the copper diffusion preventing material polishing composition having the above-described composition instead of the copper-based metal polishing composition. Accordingly, a first via fill is formed in the first opening, the periphery of which is covered with the first copper diffusion preventing film except for the surface.

Next, a second insulating film is formed on the first insulating film including the first via fill. A second opening having a shape corresponding to the second via fill reaching at least the first via fill is formed in the second insulating film. A second copper diffusion preventing film is formed on the second insulating film including the second opening. Subsequently, after a second wiring material film made of copper or a copper alloy is formed on the second copper diffusion preventing film, the second wiring material film is formed by using the copper-based metal polishing composition having the above-described composition. Polishing is performed until the second copper diffusion preventing film portion on the second insulating film excluding the second opening is exposed. Continued,
Polishing the copper diffusion prevention film portion on the second insulating film except for the second opening using the copper diffusion prevention material polishing composition having the above-described composition instead of the copper-based metal polishing composition, By forming the second via fill in which the periphery except the surface is covered with the second copper diffusion preventing film in the second opening, a semiconductor device having a multilayer wiring structure is manufactured.

On the surface of the semiconductor substrate where the first via fill is located, a diffusion layer of the same conductivity type as the substrate or a conductivity type opposite to the substrate is allowed to be formed. The former diffusion layer can be used as a substrate bias, and the latter diffusion layer can be used as a wiring layer.

As the first and second insulating films, for example, a silicon oxide film, a boron-doped glass film (BPSG film),
A phosphorus-added glass film (PSG film) or the like can be used. The second insulating film allows the surface to be covered with an insulating polishing stopper film made of silicon nitride, carbon, alumina, boron nitride, diamond, or the like.

It is preferable that at least one of the first and second insulating films is made of the above-mentioned insulating material having a relative dielectric constant of 3.5 or less.

The copper diffusion preventing film is made of, for example, TaN, Ta
Nb, W, WN, TaN, TaSiN, Ta, Co, C
It is made of one or more layers selected from o, Zr, ZrN and CuTa alloy. Such a copper diffusion barrier film preferably has a thickness of 15 to 50 nm.

As the Cu alloy, for example, Cu—Si
Alloy, Cu-Al alloy, Cu-Si-Al alloy, Cu-
An Ag alloy or the like can be used.

The first and second wiring material films made of Cu or Cu alloy are formed by sputter deposition, vacuum deposition, electroless plating, or the like. Specifically, copper or a copper alloy is deposited by a sputtering method or a CVD method, and further subjected to electroless copper plating to form first and second wiring material films made of copper or a copper alloy.

The polishing treatment with each of the polishing compositions is performed, for example, by using the polishing apparatus shown in FIG.

In the polishing treatment using the polishing apparatus shown in FIG. 2, the load applied to the polishing pad by the substrate held by the substrate holder is appropriately selected depending on the composition of the polishing composition. For example, the load is 50 to 1000 g / cm ² . Is preferred.

The polishing composition for copper-based metal used for polishing the first wiring material film and the polishing composition for copper-based metal used for polishing the second wiring material film have the same component composition and composition ratio. Even if they are present, their component compositions or composition ratios may be different from each other.

The polishing composition for a copper diffusion preventing material used for polishing the first copper diffusion preventing film and the polishing composition for a copper diffusion preventing material used for polishing the second copper diffusion preventing film have the same component composition and composition. Even if the ratio is the same, the component composition or the composition ratio may be different from each other.

According to the method of manufacturing a semiconductor device according to the present invention described above, a high-precision copper or copper alloy made of copper or a copper alloy whose first insulating film reaches the semiconductor substrate surface and whose periphery is covered with a copper diffusion preventing film is used. At least a first via fill can be formed, and at least a high-accuracy second via fill made of copper or a copper alloy connected to the first via fill and covered with a copper diffusion prevention film can be formed on a second insulating film.
As a result, a semiconductor device made of copper or a copper alloy and having a multilayer wiring structure capable of preventing contamination of the semiconductor substrate with Cu can be obtained.

[0107]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings.

(Example 1) A silicon wafer having a Cu film and a TaN film formed on a substrate holder 5 using the polishing apparatus shown in FIG. The film (or TaN film) is held upside down so as to face the polishing pad (trade name: IC1000, manufactured by Rodel) 2, and a load of 150 gf / cm ² is applied to the polishing pad 2 by the support shaft 4. Further, while rotating the turntable 1 and the holder 5 in the same direction at a speed of 103 rpm and 100 rpm, respectively, the polishing composition for copper-based metal
The Cu film and the TaN film were polished by supplying the polishing pad 2 at a rate of 00 mL / min.

<Polishing composition for copper-based metal; each component is in proportion to water> 2-quinolinecarboxylic acid (quinaldic acid); 0.67
Lactic acid; 0.67% by weight; Alumina containing θ-alumina phase; 1.67% by weight; Hydrogen peroxide; 4.67% by weight; Ammonium dodecyl sulfate; 0.576% by weight; Pyrrolidone (PVP); 0.4% by weight.

The Cu film and the TaN film were polished under the same conditions as described above, except that a polishing composition for a copper diffusion preventing material having the following composition was used.

<Polishing Composition for Copper Diffusion Preventing Material; Each Component is Percentage of Water> 2-quinolinecarboxylic acid (quinaldic acid); 0.67
Lactic acid; 0.67% by weight; Alumina containing θ-alumina phase; 1.67% by weight; hydrogen peroxide; 17% by weight; ammonium dodecyl sulfate; 0.576% by weight; polyvinylpyrrolidone ( PVP); 0.4% by weight.

Comparative Example 1 A Cu film and a TaN film were polished under the same conditions as in Example 1 except that a polishing composition for a copper-based metal having the following composition was used.

<Polishing composition for copper-based metal; the amount of each component is relative to water> 2-quinolinecarboxylic acid (quinaldic acid); 0.67
Lactic acid; 0.67% by weight Colloidal silica: 4.4% by weight Colloidal alumina: 1.47% by weight Hydrogen peroxide: 4.67% by weight Ammonium dodecyl sulfate: 0.576 % By weight Polyvinylpyrrolidone (PVP); 0.4% by weight.

The polishing rates of Cu and TaN by the polishing composition for a copper-based metal, the polishing composition for a copper diffusion preventing material of Example 1, and the polishing composition for a copper-based metal of Comparative Example 1 were measured.

As a result, the polishing rates of Cu and TaN by the polishing composition for a copper-based metal of Example 1 were doubled as compared with those of Comparative Example 1, and the polishing selectivity of Cu / TaN was 25. Was.

Further, the polishing rate of Cu and TaN by the polishing composition for copper diffusion preventing material of Example 1 is 0.6 times and 2 times that of the polishing composition for copper-based metal of Example 1, respectively. And the polishing selectivity of Cu / TaN was reduced from 25 to 7.

Example 2 A Cu film and a TaN film were polished under the same conditions as in Example 1 except that a load was set to 500 gf / cm ² using a polishing composition for a copper-based metal having the following composition.

<Polishing composition for copper-based metal; each component is in proportion to water> 2-quinoline carboxylic acid (quinaldic acid); 0.67
Lactic acid; 0.67% by weight; Alumina containing boehmite phase; 0.83% by weight; Hydrogen peroxide; 4.67% by weight; Ammonium dodecyl sulfate; 0.576% by weight; Polyvinylpyrrolidone ( PVP); 0.4% by weight.

The Cu film and the TaN film were polished under the same conditions as in Example 1 except that the load was set to 500 gf / cm ² using the polishing composition for a copper diffusion preventing material having the following composition.

<Polishing Composition for Copper Diffusion Prevention Material; Each Component is in Ratio to Water> 2-Quinolinecarboxylic acid (quinaldic acid); 0.67
Lactic acid; 0.67% by weight Alumina containing boehmite phase; 0.83% by weight Hydrogen peroxide: 17% by weight Ammonium dodecyl sulfate; 0.576% by weight Polyvinyl pyrrolidone (PVP) 0.4% by weight;

Comparative Example 2 A polishing composition for a copper-based metal having the same composition as in Comparative Example 1 was used, and the load was 500 gf / cm.
² and the Cu film and T under the same conditions as in Example 1.
The aN film was polished.

The polishing rates of Cu and TaN by the polishing composition for a copper-based metal of Comparative Example 2, the polishing composition for a copper diffusion preventing material, and the polishing composition for a copper-based metal of Comparative Example 2 were measured.

As a result, the polishing rate of Cu and TaN by the polishing composition for copper-based metal of Example 2 was 0.5 times that of Comparative Example 2, and the polishing selectivity of Cu / TaN was It was 50.

The polishing rate for Cu and TaN by the polishing composition for copper diffusion preventing material of Example 2 was 0.5 times and 2.5 times that of the polishing composition for copper-based metals of Example 2, respectively. And the polishing selectivity of Cu / TaN is 50 to 10
Decreased to.

(Example 3) The same conditions as in Example 1 were used except that a polishing composition for a copper diffusion preventing material having the following composition was used.
The film and the TaN film were polished.

<Polishing Composition for Copper Diffusion Preventing Material; Each Component is in Percentage of Water> 2-quinolinecarboxylic acid (quinaldic acid); 0.67
Lactic acid; 0.67% by weight; bayerite; 0.83% by weight; hydrogen peroxide; 17% by weight; ammonium dodecyl sulfate; 0.576% by weight; polyvinylpyrrolidone (PVP); 4% by weight.

The polishing rate of Cu and TaN by the polishing composition for a copper diffusion preventing material of Example 3 was measured. As a result, the polishing rate of Cu and TaN by the polishing composition for copper diffusion preventing material was 0.005 times and 0.5 times respectively that of the polishing composition for copper-based metal of Comparative Example 1, and Cu / TaN
Was 0.1.

(Example 4) First, as shown in FIG. 4A, on a silicon substrate 21 on which a diffusion layer such as a source and a drain (not shown) is formed on the surface, for example, a thick film as an interlayer insulating film is formed by a CVD method. after depositing the SiO ₂ film 22 of 1000nm is, the depth 500nm having a shape corresponding to the wiring layer by photoetching technique on the SiO ₂ film 22
Are formed. Subsequently, as shown in FIG. 4B, a copper diffusion preventing film 24 made of TaN having a thickness of 15 nm and a Cu film 25 having a thickness of 600 nm are formed on the SiO ₂ film 22 including the groove 23 by sputtering. Formed in order.

Next, the substrate 21 shown in FIG. 4B is held upside down on the substrate holder 5 of the polishing apparatus shown in FIG. 2, and the substrate is placed on the turntable 1 by the support shaft 4 of the holder 5. Product name of Rodel; IC10
The polishing pad 2 consisting of 00 apply a load of 500 g / cm ^2, 103 rpm the turntable 1 and the holder 5, respectively, while rotating in the same direction at 100rpm speed, the copper-based metal polishing composition from the supply pipe 3 50 ml
/ Min to the polishing pad 2 and supply the substrate 21
The Cu film 25 formed as described above was polished until the surface of the copper diffusion preventing film 24 on the SiO ₂ film 22 was exposed. Here, as the polishing composition for a copper-based metal, 0.67% by weight of 2-quinolinecarboxylic acid (quinaldic acid) and 0.67% of lactic acid were used.
% By weight, 1.67% by weight of alumina containing a θ-alumina phase, 4.67% by weight of hydrogen peroxide, 0.576% by weight of ammonium dodecyl sulfate, polyvinylpyrrolidone (PV
P) A composition having a composition of 0.4% by weight and water was used. In the polishing step, the polishing composition did not undergo any etching at the time of contact with the Cu film, and the polishing rate at the time of polishing with the polishing pad was about 600 nm / min.
For this reason, in the polishing step, the convex Cu film 25 shown in FIG. 4B was preferentially polished from the surface that is in mechanical contact with the polishing pad.

Next, the polysilicon used for polishing the Cu film was used.
Another poly-element having the same structure as that of FIG.
The substrate 2 shown in FIG.
1 is held upside down, and is supported by the support shaft 4 of the holder 5.
The substrate is made on a turntable 1 by a trade name of Rodel;
500 g / cm on polishing pad 2 made of IC1000 ^Two
Of the turntable 1 and the holder 5
In the same direction at a speed of 103 rpm and 100 rpm respectively
While rotating, supply pipe for polishing composition for copper diffusion prevention material
Supply to the polishing pad 2 at a rate of 3 to 100 ml / min
The copper diffusion preventing film 24 formed on the substrate 21
iO_TwoPolishing was performed until the surface of the film 22 was exposed. Where before
2-quinolinecal as a polishing composition for a copper diffusion preventing material
Bonic acid (quinaldic acid) 0.67% by weight, lactic acid 0.67
1.67% by weight of alumina containing θ-alumina phase
%, Hydrogen peroxide 17% by weight, ammonium dodecyl sulfate
0.576% by weight, polyvinylpyrrolidone (PVP)
One having a composition of 0.4% by weight and water was used. So
As a result, as shown in FIG.
The diffusion preventing film 24 remains and the copper diffusion preventing film 24
The dishing is suppressed in the groove 23 covered with
SiO_TwoBuried Cu wiring layer 2 substantially flush with the surface of film 22
6 was formed.

Further, after releasing the load on the polishing pad 2 by the holder 5 of the polishing apparatus and stopping the rotation of the turntable 1 and the holder 5,
Even when the Cu wiring layer 26 was brought into contact with the polishing composition, it was not dissolved (etched).

Example 5 First, as shown in FIG. 5A, an 800 nm-thick SiO 2 film was formed on a silicon substrate 31 having an n ⁺ -type diffusion layer 31 formed on the surface by CVD.
₂ after depositing the film 33 to form an interlayer insulating film,
A plurality of grooves 3 having a depth of 500 nm and a width of 400 nm corresponding to the shape of the wiring layer are formed in the O ₂ film 33 by a photoetching technique.
4 was formed. Subsequently, as shown in FIG. 5B, the SiO ₂ film 33 located at a part of the bottom of the predetermined groove 34 among the plurality of grooves 34 is selectively removed by a photo-etching technique to form the n. ^An opening 35 reaching the ⁺ type diffusion layer 31 was formed.

Next, as shown in FIG. 6C, a copper diffusion preventing film 36 of TaN having a thickness of 15 nm and a thickness of 600 nm are formed on the SiO ₂ film 33 including the groove 34 and the opening 35 by sputtering. Was deposited in this order.

Next, the substrate 32 shown in FIG. 6C is held upside down on the substrate holder 5 of the polishing apparatus shown in FIG. 2, and the substrate is held by the support shaft 4 of the holder 5 by Rodel-Nitta. A 300 g / cm ² load was applied to a polishing pad 2 made of SUBA800, and the turntable 1 and the holder 5 were each rotated at 100 rpm.
While rotating in the same direction at a speed of m, the copper-based metal polishing composition is supplied from the supply pipe 3 to the polishing pad 2 at a rate of 12.5 ml / min to deposit the Cu film 37 deposited on the substrate 21.
Was polished until the surface of the copper diffusion preventing film 36 on the SiO ₂ film 33 was exposed. Here, 2-quinoline carboxylic acid (quinaldic acid) is used as the copper-based metal polishing composition.
0.67% by weight, 0.67% by weight of lactic acid, 1.67% by weight of alumina containing a θ-alumina phase, 4.67% by weight of hydrogen peroxide, 0.576% by weight of ammonium dodecylsulfate, and 0.2% by weight of polyvinylpyrrolidone (PVP). One having a composition of 4% by weight and water was used. In the polishing step, the polishing composition does not undergo any etching at the time of contact with the Cu film, and the polishing rate at the time of polishing with the polishing pad is about 6
00 nm / min. For this reason, the convex Cu film 37 shown in FIG. 6C was preferentially polished from the surface that mechanically contacts the polishing pad.

Next, the polysilicon used for polishing the Cu film was used.
Another poly-element having the same structure as that of FIG.
The substrate 3 shown in FIG.
2 is held upside down, and is supported by the support shaft 4 of the holder 5.
The substrate is made on a turntable 1 by a trade name of Rodel;
500 g / cm on polishing pad 2 made of IC1000 ^Two
Of the turntable 1 and the holder 5
In the same direction at a speed of 103 rpm and 100 rpm respectively
While rotating, supply pipe for polishing composition for copper diffusion prevention material
Supply to the polishing pad 2 at a rate of 3 to 100 ml / min
The copper diffusion preventing film 36 formed on the substrate 32
iO_TwoPolishing was performed until the surface of the film 33 was exposed. Where before
2-quinolinecal as a polishing composition for a copper diffusion preventing material
Bonic acid (quinaldic acid) 0.67% by weight, lactic acid 0.67
1.67% by weight of alumina containing θ-alumina phase
%, Hydrogen peroxide 17% by weight, ammonium dodecyl sulfate
0.576% by weight, polyvinylpyrrolidone (PVP)
One having a composition of 0.4% by weight and water was used.

As a result, as shown in FIG. 6D, the copper diffusion preventing film 36 is formed in the groove 34 and the opening 35.
And a Cu wiring layer 38 having a dual damascene structure substantially flush with the surface of the SiO ₂ film 33 in which the dishing is suppressed in the grooves 34 and the openings 35 covered with the copper diffusion preventing film 36. Was formed. At the same time, the copper diffusion preventing film 36 remains in the groove 34, and the Cu _{2 that} is substantially flush with the surface of the SiO ₂ film 33 in which the dishing is suppressed is formed in the groove 34 covered with the copper diffusion preventing film 36. The wiring layer 39 was formed.

Since the Cu wiring layer 38 and the Cu wiring layer 39 having the dual damascene structure are embedded in the SiO ₂ film 33 via the copper diffusion preventing film 36 made of TaN, the wiring layers 38 and 39 are formed. From copper to SiO
Diffusion into the _second film 33 reaches the silicon substrate 32, thereby preventing contamination.

Further, after the load on the polishing pad 2 by the holder 5 of the polishing apparatus is released and the rotation of the turntable 1 and the holder 5 is stopped,
Even when the Cu wiring layers 38 and 39 were brought into contact with the polishing composition, they were not dissolved (etched).

Therefore, according to the fifth embodiment, the Cu wiring layer 38 having a high-accuracy dual damascene
The wiring layer 39 was formed, and a highly reliable semiconductor device in which contamination due to the activity was avoided could be manufactured.

(Embodiment 6) First, as shown in FIG.
Sea surface n⁺P-type silicon on which a p-type diffusion layer 41 is formed
For example, as a first insulating film on a substrate 42 by a CVD method,
1000nm thick SiO_TwoAfter depositing the film 43,
The SiO corresponding to the diffusion layer 31_TwoPhoto-etching on film 43
The first opening (first via hole) 44 is formed by the
Formed. Subsequently, as shown in FIG.
The SiO including one via hole 44 _TwoSpatter on the film 43
Prevention of copper diffusion made of TaN with a thickness of 20 nm by vapor deposition
After depositing the film 45, the first wiring material is formed by sputter deposition.
A first Cu film 46 having a thickness of 1100 nm, which is a film, is deposited.
Was.

Next, the polishing apparatus shown in FIG.
The substrate 42 shown in FIG.
And hold the substrate by the support shaft 4 of the holder 5.
-Product name manufactured by Del Nitta; Lab consisting of SUBA800
300 g / cm for polishing pad 2 ^TwoAnd apply the load
The table 1 and the holder 5 are each set at 100 rpm.
While rotating in the same direction at a speed, the polishing composition for copper-based metal
From the supply pipe 3 at a rate of 12.5 ml / min.
Cu film 46 supplied to the substrate 2 and deposited on the substrate 42
With the SiO_TwoThe surface of the copper diffusion preventing film 45 on the film 43 is
Polished until exposed. Here, the polishing group for copper-based metal
2-quinolinecarboxylic acid (quinaldic acid) as a product
0.67% by weight, lactic acid 0.67% by weight, θ-alumina phase
1.67% by weight of alumina containing 4.67% by weight of hydrogen peroxide
%, Ammonium dodecyl sulfate 0.576% by weight,
0.4% by weight of vinyl pyrrolidone (PVP) and water
The one having the composition was used. In the polishing step,
The polishing composition was completely etched when contacting the first Cu film.
Does not occur, the polishing rate at the time of polishing by the polishing pad is
It was about 600 nm / min. For this reason, FIG.
The convex first Cu film 46 shown in FIG.
Polished preferentially from the contacting surface.

Next, the poly film used for polishing the Cu film was used.
Another poly-element having the same structure as that of FIG.
The substrate 4 shown in FIG.
2 is held upside down, and is supported by the support shaft 4 of the holder 5.
The substrate is made on a turntable 1 by a trade name of Rodel;
500 g / cm on polishing pad 2 made of IC1000 ^Two
Of the turntable 1 and the holder 5
In the same direction at a speed of 103 rpm and 100 rpm respectively
While rotating, supply pipe for polishing composition for copper diffusion prevention material
Supply to the polishing pad 2 at a rate of 3 to 100 ml / min
The copper diffusion preventing film 45 formed on the substrate 42
iO_TwoPolishing was performed until the surface of the film 43 was exposed. Where before
2-quinolinecal as a polishing composition for a copper diffusion preventing material
Bonic acid (quinaldic acid) 0.67% by weight, lactic acid 0.67
0.83% by weight of alumina containing boehmite phase,
17% by weight of hydrogen peroxide, ammonium dodecyl sulfate 0.1%
576% by weight, polyvinylpyrrolidone (PVP) 0.4
Those having the composition of weight% and water were used.

As a result, as shown in FIG. 7C, the copper diffusion preventing film 45 remains in the first via hole 44, and the dishing also occurs in the via hole 44 covered with the copper diffusion preventing film 45. The suppressed first via fill 47 made of Cu was formed substantially flush with the surface of the SiO ₂ film 43. In addition, since the polishing composition having the above-described composition containing a surfactant has high polishing selectivity between Cu and SiO ₂ , it was possible to prevent the SiO ₂ film 43 from being thinned (thinned) in the etch-back step. Furthermore, even after the weight of the polishing pad 2 by the holder 5 of the polishing apparatus is released and the rotation of the turntable 1 and the holder 5 is stopped, even if the via fill 47 comes into contact with the polishing composition, etching is not performed. Did not progress. Subsequently, the substrate after the formation of the via fill 47 was subjected to ultrasonic cleaning using pure water to clean the surface of the SiO ₂ film 43.

Next, as shown in FIG.
The SiO containing 1 via fill 47 _TwoCVD on film 43
The second insulating film, for example, having a thickness of 1000 nm
SiO_TwoAfter depositing the film 48, the via
Said SiO located_TwoPhoto-etching technology for film 48
Thus, a second opening (second via hole) 49 was formed. Sa
In addition, the SiO_TwoPhoto-etching technology is applied to the film 48
400 nm deep groove 5 having a shape corresponding to the wiring layer
0 was formed. Then, as shown in FIG.
The SiO including the second via hole 49 and the groove 50
_Two15 nm thick TaN on the film 48 by sputter deposition
Copper diffusion prevention film 51 and second wiring material film made of
A second Cu film 52 having a thickness of 900 nm was deposited.

Next, the substrate 42 shown in FIG. 8E is held upside down in the substrate holder 5 of the polishing apparatus shown in FIG. 2 and the substrate is held by the support shaft 4 of the holder 5 by Rodel-Nitta. A 300 g / cm ² load was applied to a polishing pad 2 made of SUBA800, and the turntable 1 and the holder 5 were each rotated at 100 rpm.
While rotating in the same direction at a speed of m, a polishing composition for a copper-based metal having a composition similar to that used in the above-described etch-back step was supplied from the supply pipe 3 at a rate of 12.5 ml / min. And the second C deposited on the substrate 42
u film 52 is formed on the SiO ₂ film 48 by the copper diffusion prevention film 5.
Polishing was performed until one surface was exposed.

Next, the polysilicon used for polishing the Cu film described above was used.
Another poly-element having the same structure as that of FIG.
The substrate 4 shown in FIG.
2 is held upside down, and is supported by the support shaft 4 of the holder 5.
The substrate is made on a turntable 1 by a trade name of Rodel;
500 g / cm on polishing pad 2 made of IC1000 ^Two
Of the turntable 1 and the holder 5
In the same direction at a speed of 103 rpm and 100 rpm respectively
While rotating, expand copper with a composition similar to that described above.
100 ml / min of the polishing composition for the scattering prevention material from the supply pipe 3
To the polishing pad 2 at a speed of
The formed copper diffusion preventing film 51 is_TwoThe surface of the film 48 is exposed
Polished until it came out.

As a result, as shown in FIG. 8F, the copper diffusion preventing film 51 remains in the second via hole 49 located on the first via fill 47 and is covered with the copper diffusion preventing film 51. In the second via hole 49, C is substantially flush with the surface of the SiO ₂ film 48 in which dishing is suppressed.
A second via fill 53 made of u was formed. at the same time,
In the trench 50 covered with the copper diffusion preventing film 51, the S
A buried Cu wiring layer 54 substantially flush with the surface of the iO ₂ film 48
Was formed. In addition, since the polishing composition having the above-described composition containing a surfactant has high polishing selectivity between Cu and SiO ₂ , it was possible to prevent the SiO ₂ film 48 from being thinned (thinned) in the etch-back step. Further, after the weight of the polishing pad 2 by the holder 5 of the polishing apparatus is released and the rotation of the turntable 1 and the holder 5 is stopped, the second via-fill 53 made of Cu and the wiring layer 54 are polished by the polishing. Etching did not proceed even when contacted with the composition.

Therefore, according to the sixth embodiment, the first and second
Having SiO ₂ films 43 and 48 as insulating films of
A _first layer made of Cu substantially flush with the surface of the iO ₂ film 43
It has a multilayer wiring structure in which a via fill 47 is formed, and a _second via fill 53 made of Cu and a Cu wiring layer 54 are formed on the SiO ₂ film 48 and connected to the first via fill 47 almost flush with the surface thereof. , And the surface is flattened,
Furthermore, a semiconductor device in which the diffusion of copper from the first and second via fills 47 and 53 and the wiring layer 54 was prevented by the barrier layers 45 and 51 having a copper diffusion barrier property was able to be manufactured.

(Embodiment 7) First, as shown in FIG. 9A, a p-type silicon substrate 42 having an n ⁺ -type diffusion layer 41 formed on the surface thereof is formed on a p-type silicon substrate 42 as a first insulating film by a CVD method. After depositing an SiO ₂ film 43 having a thickness of 1100 nm, a first opening (first via hole) 44 was formed in the SiO ₂ film 43 corresponding to the diffusion layer 31 by a photo-etching technique. Further, a groove 55 having a shape corresponding to the wiring layer and having a depth of 400 nm was formed in the first SiO ₂ film 43 by a photoetching technique. Subsequently, as shown in FIG. 9B, the first via hole 44 and the groove 5 are formed.
After depositing a copper diffusion preventing film 45 made of TaN with a thickness of 20 nm on the SiO ₂ film 43 containing
A 100 nm first Cu film 46 was deposited.

Next, the polishing apparatus shown in FIG.
The substrate 42 shown in FIG.
And hold the substrate by the support shaft 4 of the holder 5.
-Product name manufactured by Del Nitta; Lab consisting of SUBA800
300 g / cm for polishing pad 2 ^TwoWeight, and the tar
The table 1 and the holder 5 are each set at 100 rpm.
While rotating in the same direction at a speed, the polishing composition for copper-based metal
From the supply pipe 3 at a rate of 12.5 ml / min.
Cu film 46 supplied to the substrate 2 and deposited on the substrate 42
With the SiO_TwoThe surface of the copper diffusion preventing film 45 on the film 43 is
Polished until exposed. Here, the polishing group for copper-based metal
2-quinolinecarboxylic acid (quinaldic acid) as a product
0.67% by weight, lactic acid 0.67% by weight, θ-alumina phase
1.67% by weight of alumina containing 4.67% by weight of hydrogen peroxide
%, Ammonium dodecyl sulfate 0.576% by weight,
0.4% by weight of vinyl pyrrolidone (PVP) and water
The one having the composition was used. In the polishing step,
The polishing composition is etched at the time of contact with the first Cu film 46.
Does not occur at all and the polishing speed when polishing with the polishing pad
The degree was about 600 nm / min. Therefore, in FIG.
The convex first Cu film 46 shown in FIG.
Polished preferentially from mechanically contacting surfaces.

Next, the polysilicon used for polishing the Cu film was used.
Another poly-element having the same structure as that of FIG.
The substrate 4 shown in FIG.
2 is held upside down, and is supported by the support shaft 4 of the holder 5.
The substrate is made on a turntable 1 by a trade name of Rodel;
500 g / cm on polishing pad 2 made of IC1000 ^Two
Of the turntable 1 and the holder 5
In the same direction at a speed of 103 rpm and 100 rpm respectively
While rotating, supply pipe for polishing composition for copper diffusion prevention material
Supply to the polishing pad 2 at a rate of 3 to 100 ml / min
The copper diffusion preventing film 45 formed on the substrate 42
iO_TwoPolishing was performed until the surface of the film 43 was exposed. Where before
2-quinolinecal as a polishing composition for a copper diffusion preventing material
Bonic acid (quinaldic acid) 0.67% by weight, lactic acid 0.67
Wt%, bayerite 0.83 wt%, hydrogen peroxide 17
% By weight, 0.576% by weight of ammonium dodecyl sulfate,
0.4% by weight of polyvinylpyrrolidone (PVP) and water
Having the following composition was used.

As a result, as shown in FIG. 9C, the copper diffusion preventing film 45 remains in the first via hole 44, and the dishing also occurs in the via hole 44 covered with the copper diffusion preventing film 45. The suppressed first via fill 47 made of Cu was formed substantially flush with the surface of the SiO ₂ film 43. At the same time, the SiO ₂ film 43 in which the dishing is suppressed is formed in the groove 55 covered with the copper diffusion prevention film 45.
A buried Cu wiring layer 56 substantially flush with the surface was formed. The polishing composition having the above-mentioned composition containing a surfactant is C
Since the polishing selectivity between u and SiO ₂ is high, thinning of the SiO ₂ film 43 in the etch-back step can be prevented. Further, after the weight of the polishing pad 2 by the holder 5 of the polishing apparatus is released and the rotation of the turntable 1 and the holder 5 is stopped, the via fill 47 and the Cu wiring layer 56 come into contact with the polishing composition. Etching did not proceed even if it was performed. Subsequently, the substrate after the formation of the via-fill 47 is subjected to ultrasonic cleaning using pure water to form SiO 2.
_{2 The} surface of the film 43 was cleaned.

Next, as shown in FIG. 10D, the S via including the first via fill 47 and the Cu wiring layer 56 is formed.
After depositing, for example, a 1000 nm thick SiO ₂ film 48 as a second insulating film on the iO ₂ film 43 by a CVD method,
A second opening (second via hole) 49 was formed in the SiO ₂ film 48 located on the via fill 37 by a photoetching technique. Subsequently, as shown in FIG. 10E, the SiO ₂ film 4 including the second via hole 49 is formed.
A copper diffusion preventing film 51 made of TaN having a thickness of 15 nm and a second wiring material film having a thickness of 9
A second Cu film 52 of 00 nm was deposited.

Next, the substrate 42 shown in FIG. 10E is held upside down on the substrate holder 5 of the polishing apparatus shown in FIG. 2 and the substrate is held by the support shaft 4 of the holder 5 by Rodel-Nitta. A 300 g / cm ² load was applied to the polishing pad 2 made of SUBA800, and the turntable 1 and the holder 5 were each placed at 100 r.
While rotating in the same direction at a speed of pm, a polishing composition for a copper-based metal having a composition similar to that described above is supplied from the supply pipe 3 to the polishing pad 2 at a rate of 12.5 ml / min. the first 2Cu film 52 deposited on 42 the SiO ₂
Polishing was performed until the surface of the copper diffusion preventing film 51 on the film 48 was exposed.

Next, the substrate 42 shown in FIG. 10E is held upside down in the substrate holder 5 of another polishing apparatus having the same structure as that of FIG. 2 adjacent to the polishing apparatus used for polishing the Cu film. Then, the substrate is supported on the turntable 1 by the support shaft 4 of the holder 5 on a turntable 1 with a polishing pad 2 made of Rodel Corporation;
While applying a load of m ² and rotating the turntable 1 and the holder 5 in the same direction at a speed of 103 rpm and 100 rpm, respectively, a polishing composition for a copper diffusion preventing material having the same composition as described above is supplied from the supply pipe 3. The copper diffusion preventing film 51 formed on the substrate 42 was supplied to the polishing pad 2 at a rate of 100 ml / min and polished until the surface of the SiO ₂ film 48 was exposed.

As a result, as shown in FIG.
The second via hole 49 located on the first via fill 47
The copper diffusion preventing film 51 remains in
A disc is formed in the second via hole 49 covered with the stop film 51.
The above-described SiO in which _TwoIt is almost flush with the surface of the film 48
A second via fill 53 made of Cu was formed. Also,
The polishing composition having the above-mentioned composition containing a surfactant contains Cu and SiO.
_TwoHigh polishing selectivity for the etch back step
And SiO_TwoPrevents thinning of the film 48
I was able to. Further, a holder of the polishing apparatus
5, the load on the polishing pad 2 is released, and
After the rotation of the table 1 and the holder 5 has stopped.
The second via fill 53 made of Cu is
Etching does not proceed even if it comes in contact with the product
Was.

Therefore, according to the seventh embodiment, the first and second
Having SiO ₂ films 43 and 48 as insulating films of
A first via fill 47 made of Cu and a Cu wiring layer 56 are formed on the iO ₂ film 43 so as to be flush with the surface thereof.
The first via fill 47 is flush with the surface of the O ₂ film 48.
Has a multilayer wiring structure in which a second via fill 53 made of Cu connected to the first and second via fills 47, 53 is formed by copper diffusion prevention films 45, 51. A semiconductor device in which diffusion of copper from the wiring layer 56 was prevented could be manufactured.

In the above embodiment, a silicon oxide film and a silicon nitride film are used as the interlayer insulating film.
A film made of an insulating material having a relative dielectric constant of 3.5 or less, such as an organic spin-on-glass, may be used. By using an insulating film having such a relative permittivity, the signal propagation speed of the Cu wiring layer embedded in the insulating film could be increased.

In the above examples, 2-quinolinecarboxylic acid was used as an organic acid as one component of the polishing composition for copper-based metals and the polishing composition for copper diffusion preventing materials. Using 6-pyridinecarboxylic acid, quinone, or the like, it was possible to exhibit the same effect as in the example.

In the manufacture of the semiconductor device having the multilayer wiring structure of the sixth and seventh embodiments, when forming the conductive members such as the first and second via fills, the copper-based metal having the same component and composition ratio is used. Although the polishing composition for polishing was used, a polishing composition for copper-based metal having a different component composition or composition ratio may be used.

[0161]

As described above, according to the present invention, in polishing copper (Cu) or copper alloy (Cu alloy) whose base is coated on a copper diffusion preventing film such as a titanium nitride film, copper or copper is polished. It is possible to provide a polishing composition for a copper-based metal, which can increase the polishing rate of the alloy and increase the polishing selectivity with the copper diffusion preventing material.

Further, according to the present invention, in the polishing of a copper diffusion preventing film such as a titanium nitride film after polishing of a copper or copper alloy, the polishing selectivity between the copper or copper alloy and the copper diffusion preventing film material is reduced. Thus, it is possible to provide a polishing composition for a diffusion preventing material capable of polishing a copper diffusion preventing film material while suppressing polishing of copper or a copper alloy.

Further, according to the present invention, at least one burying member selected from a groove and an opening is formed in an insulating film on a semiconductor substrate, and copper (Cu) or a copper alloy (Cu alloy) is formed on the insulating film. It is possible to etch back in a short time by polishing after forming a wiring material film made of, and to form a conductive member such as a high-precision embedded wiring layer whose periphery is covered except for the surface with a copper diffusion preventing film. A method for manufacturing a semiconductor device can be provided.

Further, according to the present invention, a groove and an opening are formed in an insulating film on a semiconductor substrate, and a wiring material film made of copper (Cu) or a copper alloy (Cu alloy) formed on the insulating film is formed. Provided is a method for manufacturing a semiconductor device capable of forming a wiring layer having a high-precision dual damascene structure that can be etched back in a short time by polishing after formation and has a high-precision dual damascene structure whose periphery except for the surface is covered with a copper diffusion prevention film. can do.

Further, according to the present invention, it is possible to manufacture a semiconductor device capable of forming a high-precision multi-layered wiring mainly composed of copper, the periphery of which is covered with a copper diffusion preventing film except for the surface by short-time etch back. A method can be provided.

[Brief description of the drawings]

FIG. 1 is an X-ray diffraction diagram of alumina containing a θ-alumina phase.

FIG. 2 is a schematic view showing a polishing apparatus used in the polishing step of the present invention.

FIG. 3 is a cross-sectional view showing a step of polishing a Cu film having irregularities having a copper diffusion prevention film as a base film with the polishing composition for a copper-based metal and the polishing composition for a copper diffusion prevention material of the present invention.

FIG. 4 is a sectional view showing a manufacturing step of a semiconductor device according to a fourth embodiment of the present invention.

FIG. 5 is a sectional view showing a manufacturing step of a semiconductor device according to a fifth embodiment of the present invention.

FIG. 6 is a sectional view illustrating a manufacturing step of a semiconductor device according to a fifth embodiment of the present invention.

FIG. 7 is a sectional view illustrating a manufacturing process of a semiconductor device according to a sixth embodiment of the present invention.

FIG. 8 is a sectional view illustrating a manufacturing process of a semiconductor device according to a sixth embodiment of the present invention.

FIG. 9 is a sectional view illustrating a manufacturing step of a semiconductor device according to a seventh embodiment of the present invention.

FIG. 10 is a sectional view showing a manufacturing step of the semiconductor device according to the seventh embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Turntable, 2 ... Polishing pad, 3 ... Supply pipe, 5 ... Holder, 11, 21, 31, 42 ... Silicon substrate, 15, 25, 37, 46, 52 ... Cu film, 16 ... Copper complex layer, 12 , 22, 33, 43, 48 ... SiO ₂ film, 23, 34, 50, 55 ... groove, 14, 24, 36, 45, 51 ... copper diffusion preventing film, 26, 38, 39, 54, 56 ... Cu wiring Layers 31, 41... N ⁺ -type diffusion layers, 13, 44, 49... Via holes, 18, 47, 53.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09K 3/14 550 C09K 3/14 550Z 13/00 13/00 H01L 21/306 H01L 21/306 M (72 Inventor Hideaki Hirabayashi 33, Shinisogo-cho, Isogo-ku, Yokohama-shi, Kanagawa Prefecture Inside the Toshiba Production Technology Center Co., Ltd. (72) Inventor Katsuhiro Kato 3-22-9 Shiohama, Kawasaki-ku, Kawasaki-shi, Kanagawa F-term (reference) 3C047 FF08 GG15 3C058 AA07 CA01 CB01 CB03 DA02 5F043 AA27 BB30 DD16 FF07

Claims (10)

[Claims] 1. A water-soluble organic acid which reacts with copper to form a copper complex which is substantially insoluble in water and which is more mechanically weaker than copper, and an alumina containing a θ-alumina phase or a boehmite phase. A polishing composition for a copper-based metal, comprising: at least one selected abrasive grain, an oxidizing agent and water mixed in a weight ratio of 3 to 20 times the organic acid. 2. A water-soluble organic acid which reacts with copper to form a copper complex which is substantially insoluble in water and mechanically weaker than copper, and an alumina containing a θ-alumina phase or a boehmite phase. At least one selected from bayerite
Abrasive grains and the organic acid in a weight ratio of 20 to 20 to
A polishing composition for a copper diffusion preventing material, comprising an oxidizing agent and water mixed 50 times. 3. The polishing composition according to claim 1, wherein the organic acid is 2-quinoline carboxylic acid. 4. The polishing composition according to claim 1, further comprising another organic acid having one carboxyl group and one hydroxyl group. 5. The polishing composition according to claim 1, wherein the polishing abrasive further contains colloidal alumina. 6. A step of forming at least one embedding member selected from a groove corresponding to a shape of a wiring layer and an opening corresponding to a shape of a via fill in an insulating film on a semiconductor substrate; Forming a copper diffusion preventing film on the insulating film including: forming a wiring material film made of copper or a copper alloy on the copper diffusion preventing film;
3. A step of polishing the wiring material film using the polishing composition for a copper-based metal according to the above, until at least a portion of the copper diffusion preventing film on the insulating film excluding the embedding member is exposed; Polishing at least the copper diffusion preventing film portion on the insulating film except for the embedding member using a polishing composition for diffusion preventing material, whereby the periphery excluding the surface inside the embedding member has the copper diffusion preventing film. Forming at least one conductive member selected from a wiring layer and a via fill covered with the semiconductor device. 7. The copper diffusion preventing film is made of TaN, TaN.
b, W, WN, TaN, TaSiN, Ta, Co, C
7. It is made of one or more layers selected from o, Zr, ZrN and CuTa alloy.
The manufacturing method of the semiconductor device described in the above. 8. The copper alloy is a Cu—Si alloy, Cu—
The method according to claim 6, wherein the material is selected from the group consisting of an Al alloy, a Cu-Si-Al alloy, and a Cu-Ag alloy. 9. a step of forming a groove having a shape corresponding to a wiring layer in an insulating film on the semiconductor substrate and an opening reaching the surface of the semiconductor substrate in a portion of the interlayer insulating film located at a part of a bottom of the groove; Forming a copper diffusion preventing film on the insulating film including the inner surface of the groove and the opening; forming a wiring material film made of copper or a copper alloy on the copper diffusion preventing film;
A step of polishing the wiring material film using the polishing composition for a copper-based metal according to claim 1 until the portion of the copper diffusion preventing film on the insulating film excluding at least the groove and the opening is exposed; Polishing at least a portion of the copper diffusion preventing film on the insulating film except for the groove and the opening using the polishing composition for copper diffusion preventing material according to 2, thereby removing a surface in the opening and the groove. Forming a wiring having a dual damascene structure, the periphery of which is covered with the copper diffusion preventing film. 10. A step of forming a first opening having a shape corresponding to at least a first via fill in a first insulating film on a semiconductor substrate; forming a first opening on the first insulating film including an inner surface of the first opening. A step of forming a copper diffusion barrier film; a step of forming a first wiring material film made of copper or a copper alloy on the first copper diffusion barrier film; 3. The polishing composition for a copper diffusion preventing material according to claim 2, wherein the first wiring material film is polished until at least the first copper diffusion preventing film portion on the first insulating film excluding the first opening is exposed. Polishing at least the copper diffusion preventing film portion on the first insulating film except for the first opening, so that the periphery of the first opening except the surface is the first.
Forming a first via fill covered with a copper diffusion preventing film; forming a second via fill on the first insulating film including the first via fill;
Forming an insulating film; forming a second opening in the second insulating film at least corresponding to the second via fill reaching the first via fill; the second insulating film including the second opening 2. A polishing composition for a copper-based metal according to claim 1, wherein a step of forming a second copper diffusion preventing film thereon; a step of forming a second wiring material film made of copper or a copper alloy on the second copper diffusion preventing film; The second wiring material film using the second
Polishing the second copper diffusion preventing film portion on the second insulating film excluding the opening until the second copper diffusion preventing film portion is exposed; Polishing the portion of the copper diffusion preventing film on the removed second insulating film, thereby forming the second via fill in which the periphery except the surface is covered with the second copper diffusion preventing film in the second opening. A method for manufacturing a semiconductor device, comprising: