KR20120123272A - Phosphorous-containing copper anode for electrolytic copper plating, method for manufacturing same, and electrolytic copper plating method - Google Patents

Abstract

Provided are a phosphorus-containing copper anode for electro-copper plating capable of reducing plating defects due to slime, a manufacturing method thereof, and an electro-copper plating method using the same. After processing the phosphorus-containing copper for electroplating to impart a work strain, and then recrystallization heat treatment, the total grain boundary length L of the grain boundaries of the grains of the copper grains on the anode surface is converted to per unit area of 1 mm 2. L _N, and converted the entire special grain boundary length L _σ of special grain boundaries by the unit area per 1 ㎟ unit entire special grain boundary length of the special grain boundary length ratio of L _{σ N} L _σN / L _N is, the grain boundary tissues becomes equal to or greater than 0.4 The black film is uniformly formed in the initial stage of electro-copper plating, and the plating defect is reduced by preventing the black film from falling off.

Description

Phosphorus-containing copper anode for electro-copper plating, its manufacturing method and electro-copper plating method

The present invention, for example, suppresses the generation of anode slime generated from a phosphorous-containing copper anode electrode when performing electro-copper plating on a semiconductor wafer or the like, and contaminates the surface of the cathode made of the semiconductor wafer or the like. The present invention relates to a phosphorus-containing copper anode for electroplating copper plating that prevents the occurrence of plating defects, a method for producing the phosphorus-containing copper anode, and an electrocopper plating method using the phosphorus-containing copper anode electrode.

This application claims priority based on Japanese Patent Application No. 2010-003718 for which it applied to Japan on January 12, 2010, and Japanese Patent Application 2010-141721 for which it applied to Japan on June 22, 2010, The content Is used here.

Conventionally, electrocopper plating using electrocopper or oxygen-free copper has been performed as an anode electrode for electrocopper plating, but a large amount of anode slime is likely to occur, and plating defects are likely to occur in the workpiece. There was a problem.

And in order to solve this, electro copper plating which used phosphorus containing copper as an anode electrode was performed.

According to the electrolytic copper plating using the phosphorus containing copper anode, since the black film which consists of nitrous oxide, copper powder, etc. as a main component is formed in the anode surface at the time of electrolysis, generation | occurrence | production of anode slime is reduced and as a result, the plating defect Incidence has also been reduced. However, for example, in the case of forming a precise copper wiring for a semiconductor wafer or the like, even if electroplating using phosphorus-containing copper as an anode, the prevention of plating defects such as contamination and protrusion on the surface of the semiconductor wafer is sufficiently performed. Can not.

Therefore, in recent years, while defining the oxygen content contained in the anode, the electro-copper plating (see Patent Document 1) using the pure copper anode that defines the crystal grain size of the anode electrode, or the phosphorus content contained in the anode In addition, electro-copper plating (refer patent documents 2, 3) using the phosphorus containing copper anode which prescribed | regulated the crystal grain diameter of an anode electrode was developed, and reduction of an anode slime and prevention of a plating defect are aimed at.

Japanese Patent No. 4011336 Japanese Patent No. 4034095 Japanese Patent No.4076751

In electrocopper plating using the conventional phosphorus containing copper anode, with the progress of electrolysis, the black film which has copper powder, copper nitrous oxide, phosphide copper, copper chloride, etc. as a main component is formed in the phosphorus containing copper anode surface. Electrolysis proceeds further, and when this black film grows thick, it will fall out from the phosphorus containing copper anode surface, and it will cause anode slime. In addition, the dropped black film diffuses in the plating bath and adheres to the surface of the plated material (cathode surface), which causes contamination of plating surfaces such as semiconductor wafers and plating defects.

Therefore, the present invention suppresses the generation of anode slime even when forming an accurate copper wiring for a semiconductor wafer or the like by electro-copper plating, and contaminates the surface of the plated material such as a semiconductor wafer. It is one object of the present invention to provide a phosphorus-containing copper anode for electro-copper plating that can prevent occurrence of plating defects such as protrusions and the like.

In addition, to provide a new method for producing a phosphorus-containing copper anode for electro-copper plating that can reduce the occurrence of anode slime and prevent the occurrence of plating defects such as contamination and protrusions on the surface of the plated material. For other purposes.

Moreover, by using the said phosphorus containing copper anode for electroplating, it is possible to reduce the generation of anode slime and plating defects such as contamination and protrusion on the surface of the plated material such as a semiconductor wafer. It is another object of the present invention to provide an electrocopper plating method capable of preventing the occurrence of oxidization.

MEANS TO SOLVE THE PROBLEM The present inventors earned the following knowledge as a result of earnestly researching the relationship of the form of the crystal grain boundary of a phosphorus containing copper anode at the time of electrocopper plating, the generation of an anode slime, and the plating defect.

In the case of electro-copper plating using a conventional phosphorus-containing copper anode, the black film grows thickly and drops off with the progress of electrolysis, resulting in the disproportionation reaction of monovalent copper, for example,

2Cu ⁺ → Cu (powder) + Cu ^{2 +}

This is because metal copper or nitrous oxide is produced by the process. Since the property of the black film formed at the beginning of electrolysis affects to the last, it is important to form a black film which is uniform in the initial stage of electrolysis and is less likely to generate monovalent copper ions (Cu ⁺ ). From the above viewpoints, all the conditions which form the black film which is uniform at an initial stage of electrolysis, and generate | occur | produces monovalent copper ion (Cu ⁺ ) little are examined. As a result, it was found that the form of the crystal grain boundary of the phosphorus-containing copper anode has a great influence on the properties of the black film formed at the initial stage of electrolysis.

That is, the present inventors raise the formation rate of what is called a special grain boundary in the grain boundary of the crystal grain of the phosphorus containing copper anode surface in the phosphorus containing copper anode for electrocopper plating, and unit the total special grain boundary length Lσ of a special grain boundary. When the unit total special grain boundary length Lσ _N converted to per 1 mm 2 area becomes equal to or more than a specific value for the unit total grain boundary length L _N converted to the total grain boundary length L of all grains per unit area of 1 mm 2 (Lσ _N / L _N ? 0.4) was found to be able to form a black film uniformly throughout the anode in the initial stage of electrolysis. As a result, it was found that the dropping of the black film can be prevented, and the plating defect caused by the anode slime can be greatly reduced.

Here, the special grain boundary means "Trans. Met. Soc. AIME, 185, 501 (1949), which corresponds to a grain boundary of 3? Metallurgica. Vol. 14, p.1479, (1966) ", a unique site corresponding grid orientation defect Dq in the art as described in the corresponding grain boundary, is defined as a grain boundary that satisfies ^{Dq ≤ 15 ° / Σ 1/} 2.

Further, the inventors of the present invention, in the production of the phosphorus-containing copper anode for electro-copper plating, subjected to predetermined cold working and hot working to impart processing deformation, and then recrystallization heat treatment at a predetermined temperature range (350 to 900 ° C). By carrying out, it was found out that among the crystal grain boundaries existing on the surface of the copper anode, a phosphorus-containing copper anode for electro-copper plating with a high formation rate of so-called special grain boundaries (Lσ _N / L _N ≥ 0.4) can be produced. will be.

In addition, the present inventors used a copper-containing phosphorus anode (Lσ _N / L _N ≥ 0.4) having a high formation rate of special grain boundaries, for example, when copper plating a semiconductor wafer or the like, the semiconductor wafer surface was contaminated or raised. It was found out that precise copper wiring without plating defects, such as these, can be formed.

The 1st aspect of this invention is a phosphorus containing copper anode for electroplating WHEREIN: An electron beam is irradiated to each crystal grain of an anode surface using a scanning electron microscope, and crystal grains whose orientation orientation difference between adjacent crystal grains is 15 degrees or more. Using the interface as the crystal grain boundary, the total grain boundary length L of the grain boundary in the measurement range was measured, and the total unit grain boundary length L _N converted to this per unit area of 1 mm 2 was obtained. Irradiating an electron beam to each crystal grain on the surface of the anode, determining the position of the crystal grain boundary where the interfaces of the adjacent grains constitute a special grain boundary, and measure the total special grain boundary length Lσ of the special grain boundary, When the total unit specific grain boundary length Lσ _N is obtained by converting it to per unit area of 1 mm 2, the unit total grain boundary length of the measured grain boundary is determined. L _N and, determining that the same special grain boundary length ratio of the measurements taken by the unit total special grain boundaries of the special grain boundary length Lσ _N Lσ _N / L _N, satisfies the relationship Lσ _N / L _N ≥ 0.4 characterized in that it has a grain boundary organization It is a phosphorus containing copper anode for electroplating.

The phosphorus containing copper anode for electroplating of the 1st aspect of this invention may contain phosphorus of 100-800 ppm by mass%.

The phosphorus containing copper anode for electroplating of the 1st aspect of this invention may be 3-1000 micrometers in average crystal grain diameter.

According to the second aspect of the present invention, after the phosphorus-containing copper for electroplating is processed to impart a work strain, a recrystallization heat treatment is performed at 350 to 900 ° C., so that the special grain boundary length ratio Lσ _N / L _N is 0.4 or more. It is a manufacturing method of the phosphorus containing copper anode for electroplating characterized by the above-mentioned.

In the phosphorus containing copper anode manufacturing method for electroplating of 2nd aspect of this invention, the said process may be performed by at least any one of cold work or hot work.

In the method for producing a phosphorus-containing copper anode for electroplating according to the second aspect of the present invention, the cold working and recrystallization heat treatment, the hot working and recrystallization heat treatment, or a combination thereof are treated with a special grain boundary length ratio Lσ _N / L _N of 0.4. You may carry out repeatedly until it becomes abnormal.

In the phosphorus containing copper anode manufacturing method for electroplating of the 2nd aspect of this invention, hot working with a reduction ratio of 5 to 80% is performed in the temperature range of 400-900 degreeC, and the said process deformation for 3 to 300 second after that. You may hold | maintain statically without adding and recrystallization heat processing may be performed.

In the phosphorus containing copper anode manufacturing method for electroplating of the 2nd aspect of this invention, cold working of 5 to 80% of a reduction ratio is performed, and it heats in the temperature range of 350-900 degreeC after that, and it is 5 minutes-5 hours. In addition, the crystallization heat treatment may be performed without static addition of the above processing strain.

The electrocopper plating method of the 3rd aspect of this invention irradiates an electron beam to each crystal grain of an anode surface using a scanning electron microscope, and determines the interface of the crystal grain whose orientation orientation difference of adjacent crystal grains is 15 degrees or more. Using the system, the total grain boundary length L of the grain boundaries in the measurement range was measured, and the unit total grain boundary length L _N, which was converted into per unit area of 1 mm 2, was obtained, and the anode was also used in the same manner. Electron beams are irradiated to each crystal grain on the surface to determine the positions of crystal grain boundaries at which interfaces between adjacent crystal grains constitute a special grain boundary, and measure the total special grain boundary length Lσ of the special grain boundary, which is measured in unit area of 1 mm 2. If the calculated an entire special grain boundary length Lσ _N unit in terms of sugars, above the grain boundary unit measuring the total grain boundary length L and _N, the same phase The units of measurement special grain boundaries entire special grain boundary length Lσ _N special grain boundary length ratio Lσ _N / L _N is, Lσ _N / L _N ≥ 0.4, which satisfies the relationship determined using a phosphorus-containing copper anode for electroplating with a grain boundary structure of the Electric copper plating method.

According to the phosphorus containing copper anode for electrocopper plating of this invention, its manufacturing method, and the electrocopper plating method, even if an accurate copper wiring with respect to a semiconductor wafer etc. is formed by electrocopper plating, for example, it is an anode slime. Can be prevented from occurring, and plating defects such as contamination and protrusions caused by slime on the surface of a plated material such as a semiconductor wafer can be prevented.

1 (a) to 1 (d) are schematic diagrams showing a dissolution progress state of an anode surface by electrolysis, and FIG. 1 (a) is an initial state in which electrolysis is initiated, and FIG. 1 (b) is a fixed time starting electrolysis. In the state where the selective dissolution of the grain boundary at the elapsed time has started, FIG. 1C shows that the dissolution of the current density due to the shape factor occurs as a result of the selective dissolution of the grain boundary. 1 (d) shows a state in which undissolved crystal grains peel and fall off together with a black film (surface oxide film) formed on the anode surface by melting of grain boundaries.
The EBSD analysis result of this invention 3 is shown, a thick line shows a special grain boundary, and a thin line shows a general grain boundary (the same also about FIGS. 3-9).
Fig. 3 shows the EBSD analysis results of the present invention 7.
4 shows the result of EBSD analysis of the present invention 11. FIG.
5 shows the result of EBSD analysis of the present invention 13. FIG.
6 shows the result of EBSD analysis of the present invention 21.
7 shows the result of EBSD analysis of the present invention 27.
8 shows the results of EBSD analysis of Comparative Example 4. FIG.
9 shows the EBSD analysis results of Comparative Example 6. FIG.

MEANS TO SOLVE THE PROBLEM The present inventors obtained the following knowledge, as a result of investigating the progress of melt | dissolution of the phosphorus containing copper anode surface in electrocopper plating.

As shown in the schematic diagrams of Figs. 1 (a) to 1 (d), in the initial state (a) in which electrolysis is initiated, no large change occurs on the anode surface. However, in the state (b) after a certain time has passed after the start of electrolysis, the crystal grains on the anode surface start to dissolve selectively at grain boundaries that are chemically unstable compared to those in the particles. Further, in the state (c) in which the electrolysis proceeds, as a result of selectively dissolving the grain boundaries, nonuniformity in the current density due to the shape factor occurs, and therefore, the grain boundaries selectively dissolve more rapidly. Further, in the state (d) in which the electrolysis proceeds, dissolution of grain boundaries proceeds, and together with the black film (surface oxide film) formed on the anode surface, undissolved crystal grains come off and fall off, which causes anode slime. This also causes plating failure. In addition, a new surface is formed in the anode portion where the undissolved crystal grains are peeled off and peeled off, a voltage fluctuation occurs, and it becomes increasingly difficult to perform stable electrolytic operation.

Based on the above findings, the present inventors further studied an anode which does not cause selective dissolution (non-uniform dissolution) from the grain boundary with the passage of the electrolysis time as the phosphorus-containing copper anode for electro-copper plating. As a result, the following was found. Special grain boundaries as defined above in the phosphorus-containing copper anode (corresponding grain boundaries belonging to 3? Σ ≤ 29 in the Σ value, and intrinsic corresponding site lattice orientation defects Dq in the corresponding grain boundaries are Dq ≤ 15 ° / Σ the entire grain boundary length L of the crystal grain boundaries of the ^1/2 crystal grain boundary) units in terms of total special grain boundary length Lσ the unit area per 1 ㎟ the entire special grain boundary length and Lσ _N, phosphorus-containing copper anode that satisfies when the entire grain boundary length of a unit in terms of a unit area per 1 ㎟ the special grain boundary length ratio Lσ _N / L _N of L _N, having a grain boundary organization which satisfies a relation Lσ _N / L _N ≥ 0.4, crystal structural stability to In addition, the ratio of chemically stable special grain boundaries increases. When the ratio of the said special grain boundary increases, the said selective dissolution of a grain boundary will hardly generate | occur | produce, and peeling and peeling of undissolved crystal grains will be suppressed and a uniform black film will be formed. As a result, generation of anode slime is reduced, and at the same time, generation of plating defects due to slime is also reduced.

The total grain boundary length L can be calculated | required using a scanning electron microscope. First, an electron beam is irradiated to each crystal grain of an anode surface, and the orientation data of a crystal is calculated | required from the obtained backscattered electron diffraction pattern. Next, based on the orientation data of each crystal, the total grain boundary length L of the crystal grain boundaries in a measurement range is calculated | required using the interface of the crystal grain whose orientation orientation difference of adjacent crystal grains is 15 degrees or more as a crystal grain boundary.

When the special grain boundary length ratio Lσ _N / L _N is Lσ _N / L _N <0.4, the selective dissolution of the crystal grain boundary at the time of electrolysis cannot be suppressed, resulting in the formation of a uniform black film, the reduction of the occurrence of anode slime, and the slime origin. Since the occurrence of plating defects cannot be reduced, the special grain boundary length ratio Lσ _N / L _{N was set} to Lσ _N / L _N ≧ 0.4.

It is preferable that the phosphorus containing copper anode of this invention contains phosphorus of 100-800 ppm by mass%. If the phosphorus content is out of this range, no stable black film is formed and anode slime occurs.

Moreover, it is preferable that the average crystal grain diameter (counted as a pair crystal grain) of the phosphorus containing copper anode of this invention is 3-1000 micrometers. If the average grain size is out of this range, more anode slime occurs.

One of the special grain boundaries entire special grain boundary length in terms of the Lσ the unit area per 1 ㎟ unit entire special grain boundary length Lσ _N and the grain boundary entire grain boundary length was converted to L by the unit area per 1 ㎟ unit entire grain boundary length L _N of Phosphorus-containing copper anodes having a grain boundary structure where the special grain boundary length ratio Lσ _N / L _N satisfies the relationship of Lσ _N / L _N ≥ 0.4 are processed (cold processing and And / or hot working) to impart a work strain, and then, may be produced by performing a recrystallization heat treatment at 350 to 900 ° C.

As a specific manufacturing example, as a manufacturing example (A), after performing the hot working of 5 to 80% of reduction ratio to the phosphorus containing copper for electroplating in the temperature range of 400-900 degreeC, for 3 to 300 second, The method of manufacturing a phosphorus-containing copper anode for electroplating having a grain boundary structure satisfying the relationship of Lσ _N / L _N ? 0.4 by maintaining statically without performing work deformation and carrying out a recrystallization heat treatment.

Moreover, as another manufacturing example, as a manufacturing example (B), after cold working of 5 to 80% of a reduction ratio, it heats in the temperature range of 350-900 degreeC, and is static without adding the said processing deformation for 5 minutes-5 hours. And the recrystallization heat treatment is carried out, and a method for producing a phosphorus-containing copper anode for electroplating having a grain boundary structure satisfying the relationship of Lσ _N / L _N ? 0.4 is mentioned.

After imparting strain by hot working or cold working of the specific reduction ratios described in Production Examples (A) and (B), recrystallization is carried out in a state that is statically maintained without imparting strain in the recrystallization temperature range. Formation of a grain boundary is accelerated | stimulated, the ratio of the whole unit special grain boundary length Lσ _N can be raised, and the value of the special grain boundary length ratio Lσ _N / L _N can be made 0.4 or more.

Further, the above-mentioned hot working, cold working, and recrystallization heat treatment are repeatedly performed several times, so that a grain boundary structure of Lσ _N / L _N ? 0.4 is obtained.

Special grain boundary length Lσ _N of unit of special grain boundary and special grain boundary length ratio Lσ _N / L _N of unit grain boundary length L _N of grain boundary have crystal grain boundary structure satisfying relationship of Lσ _N / L _N ≥ 0.4 By carrying out electrocopper plating using a phosphorus containing copper anode as an anode for electroplating, generation | occurrence | production reduction of an anode slime can be aimed at. For example, when copper plating on the surface of a to-be-plated material, such as a semiconductor wafer, it becomes possible to form the precise copper wiring on the surface of a semiconductor wafer without plating defects, such as a contamination and protrusion.

The determination of the grain boundaries of the phosphorus-containing copper anode and the measurement of the unit-wide grain boundary length L _N are performed by using an electron microscope to irradiate each crystal grain on the surface of the anode with an electron beam and to obtain an orientation of a crystal obtained from the backscattered electron diffraction pattern. Based on the data, the total grain boundary length L of the grain boundaries in the measurement range is measured using the interface of the crystal grains having an orientation orientation difference of 15 ° or more as the crystal grain boundary, and this is divided by the measurement area to obtain a unit area of 1 mm 2. It carries out by converting into sugar whole unit grain boundary length. In addition, the measurement of the specific grain boundary and the unit-wide special grain boundary length Lσ _N are similarly carried out using a field emission scanning electron microscope to irradiate the electron beams to the respective grains on the anode surface, and the interface of the crystal grains adjacent to each other is special. While determining the position of the grain boundary constituting the grain boundary, the total special grain boundary length Lσ of the special grain boundary is measured, and this is divided by the measurement area and converted into the unit-specific special grain boundary length per unit area of 1 mm 2.

Specifically, to an EBSD measuring apparatus (S4300-SE manufactured by HITACHI, OIM Data Collection manufactured by EDAX / TSL) and an analysis software (OIM Data Analysis ver.5.2 manufactured by EDAX / TSL) using a field emission scanning electron microscope By this, crystal grain boundaries and special grain boundaries can be specified and the length thereof can be calculated.

In addition, the measurement of the average crystal grain size (counted as a pair crystal grain) of a phosphorus containing copper anode determines a grain boundary from the result obtained by the said EBSD measuring apparatus and analysis software, and determines the number of crystal grains in an observation area. By calculating, dividing the area area by the number of crystal grains, calculating the crystal grain area, and converting it into a circle, the average grain size (diameter) can be obtained.

Next, an Example demonstrates this invention concretely.

Example

In the recrystallization material or cast material of phosphorus containing copper which contains the predetermined amount of P (phosphorus) shown in Table 1, and whose total content of Pb, Fe, Sn, Zn, Mn, Ni, Ag as an unavoidable impurity is 0.002 mass% or less, Similarly, under the conditions shown in Table 1, hot working (temperature, processing method, processing rate), cold working (processing method, processing rate), recrystallization heat treatment (temperature, time) or repetitively performing these recrystallization heat treatments Then, it cooled by water and produced the phosphorus containing copper anode (it is called this invention anode) 1-28 of this invention of the predetermined size shown in Table 3.

In addition, in the Example of Table 1, when performing a hot work recrystallization heat treatment, a cold work recrystallization heat treatment, or these required times repeatedly, only the repetition in the same conditions is given, but it is not necessarily required to repeat on the same conditions. It is, of course, possible to carry out the repetition under different conditions (processing temperature, processing method, processing rate, holding temperature, holding time) within the range of the conditions defined in the claims of the claims.

The above-described anode of the present invention manufactured by the above EBSD measuring apparatus (S4300-SE manufactured by Hitachi, OIM Data Collection manufactured by EDAX / TSL) and analysis software (OIM Data Analysis ver.5.2 manufactured by EDAX / TSL) , Grain boundaries and special grain boundaries were specified, and the total unit grain boundary length L _N and the total unit specific grain boundary length Lσ _N were obtained.

In Table 3, L _N , Lσ _N and the special grain boundary length ratio Lσ _N / L _N are shown.

Table 3 also shows the value of the average grain size determined from the results obtained by the EBSD measuring apparatus and analysis software.

2-7, the EBSD analysis result of this invention anode 3, 7, 11, 13, 21, 27 is shown, respectively.

For comparison, for the phosphorus-containing copper anode material prepared above, hot working (temperature, processing method, working rate), cold working (at least one condition is a condition outside the scope of the present invention) shown in Table 2 Processing method, processing rate) and recrystallization heat treatment (temperature, time) were performed to prepare phosphorus-containing copper anodes (hereinafter referred to as comparative example anodes) 1 to 8 of the comparative examples shown in Table 4.

Moreover, also about the comparative example anode manufactured above, unit whole grain boundary length L _N , unit whole special grain boundary length Lσ _N , special grain boundary length ratio Lσ _N / L _N, and average crystal grain diameter were calculated | required. .

This value is shown in Table 4.

8 and 9 show the results of EBSD analysis of Comparative Examples Anodes 4 and 6, respectively.

Using the present invention anodes 1 to 28 and comparative examples anodes 1 to 8 (all anode surface areas are 530 cm 2), the semiconductor wafer is used as a cathode, and five copper wafers are subjected to electrocopper plating under the following conditions. It was.

Plating solution: CuSO ₄ · 5H ₂ O 200 g / ℓ,

50 g / l H ₂ SO ₄ ,

Cl ^- 50 ppm,

        Additive polyethylene glycol ： 400 ppm (molecular weight 6000)

Plating condition: 25 ℃, liquid temperature

            Cathode current density 2 A / dm 2,

            Plating time 1 hour / sheet,

With respect to the present invention anodes 1 to 28 and comparative examples anodes 1 to 8, the amount of anode slime generated from the start of electrocopper plating to the completion of electrocopper plating of the fifth wafer (5 hours) was measured.

Moreover, the surface of the semiconductor wafer after plating was observed with the optical microscope, and the protrusion formed in the wafer surface of 5 micrometers or more in height was regarded as a defect, and the number of protrusion defects was counted.

These measurement results are shown in Tables 5 and 6.

From the results shown in Tables 5 and 6, according to the production method of the phosphorus-containing copper anode for electrocopper plating, the phosphorus-containing copper anode for electrocopper plating, and the electrocopper plating method, for example, a semiconductor wafer or the like Even in the case of forming a precise copper wiring, it can be seen that the generation of anode slime can be suppressed and plating defects such as contamination and protrusions on the surface of the plated material such as a semiconductor wafer can be prevented. .

In the comparative example anode in which the special grain boundary length ratio Lσ _N / L _N is less than 0.4, it was found that not only the amount of anode slime was generated, but also many plating defects due to slime were generated.

Industrial availability

As described above, the present invention has an excellent effect that the generation of anode slime can be suppressed at the time of electro-copper plating, and the occurrence of plating defects on the surface of the plated material can be prevented. When applied to precise copper wiring formation, since industrial defects, such as a contamination on a semiconductor wafer and generation | occurrence | production of a defect, can be prevented, industrial utility is very high.

Claims (9)

In the phosphorus-containing copper anode for electroplating,
(a) An electron beam is irradiated to each crystal grain of an anode surface using a scanning electron microscope, and the grain boundary in a measurement range is made into the grain boundary as the interface of the crystal grain whose orientation orientation difference of adjacent crystal grains is 15 degrees or more. The total grain boundary length L of was measured, and the unit total grain boundary length L _N obtained by converting it to per unit area of 1 mm 2 was obtained.
(b) Using a scanning electron microscope, electron beams are irradiated to each crystal grain on the surface of the anode, and the positions of the crystal grain boundaries at which the interfaces of the adjacent crystal grains constitute a special grain boundary are determined. In the case where the grain boundary length Lσ is measured and the total unit specific grain boundary length Lσ _N is obtained by converting it to per unit area of 1 mm 2,
(c) The unit total grain boundary length L _N of the measured grain boundary and the special grain boundary length ratio Lσ _N / L _N of the unit total special grain boundary length Lσ _N of the special grain boundary measured as above,
Lσ _N / L _N ≥ 0.4
A phosphorus-containing copper anode for electroplating, characterized by having a grain boundary structure satisfying the relationship of. The method of claim 1,
The phosphorus containing copper anode for electroplating containing 100-800 ppm of phosphorus by mass%. The method according to claim 1 or 2,
The phosphorus containing copper anode for electroplating whose average crystal grain size is 3-1000 micrometers. Of claim 1 by carrying out processing in a phosphorus-containing copper for electroplating characterized in that after giving a processing strain, the, special grain boundary length ratio Lσ _N / L _N by carrying out the recrystallization heat treatment at 350 ~ 900 ℃ to 0.4 The manufacturing method of the phosphorus containing copper anode for electroplating described in the above. The method of claim 4, wherein
The said process is a manufacturing method of the phosphorus containing copper anode for electroplating performed by at least any one of cold work or hot work. The method according to claim 4 or 5,
Preparation of phosphorus-containing copper anode for electroplating, which is repeatedly cold processed and recrystallized heat treatment, or hot worked and recrystallized heat treatment, or a combination thereof until the special grain boundary length ratio Lσ _N / L _N is 0.4 or more. Way. The method of claim 4, wherein
Phosphorus for electroplating, which is subjected to hot working with a reduction ratio of 5 to 80% at a temperature in the range of 400 to 900 ° C., and then statically maintained without applying the above processing deformation for 3 to 300 seconds, and subjected to recrystallization heat treatment. Method for producing a containing copper anode. The method of claim 4, wherein
Cold working is performed at a reduction ratio of 5 to 80%, and then heated to a temperature range of 350 to 900 ° C, held static for 5 minutes to 5 hours without applying the above processing strain, and recrystallization heat treatment is performed. Method for producing a phosphorus-containing copper anode for electroplating. The electrocopper plating method using the phosphorus containing copper anode for electroplating of Claim 1.

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