JP2003049264A - Tungsten sputtering target and manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a W sputtering target capable of improving the film thickness in-plane uniformity of a W film deposited on a substrate and further capable of reducing particle generation, and its manufacturing method. SOLUTION: In the W sputtering target, the half-width of peak of crystal plane (110) obtained by X-ray diffraction of the plane to be sputtered is <=0.35. In this method for manufacturing the high-purity W sputtering target, high-purity W powder is pressed and sintered and the resultant sintered compact is machined into target shape and is then subjected to grinding consisting of at least either of rotary grinding and polishing and further to polishing consisting of at least either of etching and inverse sputtering to undergo finishing.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a tungsten (W) sputtering target and a method for manufacturing the same.

[0002]

2. Description of the Related Art In electronic parts represented by semiconductor elements and liquid crystal display elements, tungsten (W), molybdenum (Mo),
Tantalum (Ta), titanium (Ti), zirconium (Z
High purity metals such as r) and cobalt (Co), and silicide compounds of these metals are used.

In recent years, these electronic parts are making rapid progress. Especially in semiconductor devices such as DRAMs, logics, and flash memories, the precision of fine processing technology for forming electrodes and wiring has been increased due to the demand for high integration, high reliability, high functionality, and high speed. Is also increasing.

Further, in order to achieve the above-mentioned requirements, it is essential to reduce the resistance of the material forming the wiring and electrodes.

As a material for electrodes and wirings used in LSIs so far, silicide electrodes represented by, for example, MoSix and WSix have been used, but studies of materials having lower resistance have been actively conducted. ing. Among them, W has low resistance and excellent heat resistance, and is starting to be noticed as a material for future electrodes and wiring.

Such electrodes and wirings made of W can be obtained by forming a W thin film on a substrate and then forming it into a predetermined wiring shape by etching or the like. As a method for forming this W thin film, a sputtering method and a CVD method can be cited as typical film forming methods.

Conventionally, the sputtering method has been the main method for forming electrodes and wirings. In the sputtering method, a W film is formed by sputtering a rare gas represented by Ar or Kr by a W sputtering target in a vacuum apparatus.

The W film can also be formed by a technique using the CVD method represented by the blanket W. However, the sputtering method has a higher film forming rate than the CVD method, and the plasma damage to the base film is small,
Moreover, there is an advantage that it is easy to handle, and it is highly likely that the sputtering method will be mainly adopted as a future electrode forming method.

[0009]

By the way, at present, LSI
The size of the Si wafer used in is shifting from 6 inches to 8 inches, and this 8 inch size is mainly used, but it is predicted that it will be further scaled up to 12 inches (Φ300 mm) in the future. There is. The size of the sputtering target that corresponds to the 8-inch Si wafer depends on the type of sputtering device.
Generally, it is equivalent to Φ300 mm. Wafers in the 12-inch class are probably required to have a target size of 400 mm or more.

As a problem that accompanies the scale-up of the wafer size, first, there is a reduction in the in-plane uniformity of the film thickness of a thin film formed from a large target. In particular, the electrodes used in the LSI vary in specific resistance due to the difference in film thickness, and as a result, affect the characteristics of the transistor. In other words, if the film-thickness uniformity of the electrode-formed thin film is not good, the yield of the LSI is reduced and the LSI manufacturer is seriously damaged.

The in-plane uniformity of the film thickness of a thin film formed by sputtering affects various parameters such as sputtering conditions, specifically, input power value, gas pressure, distance between target and substrate. receive. However, even if these parameters are controlled, the in-plane uniformity of the film thickness obtained by using the currently commercially available sputtering apparatus is limited to about 3%.

Another problem is particles (dust) generated from the sputtering target. This is because if particles generated during or after film formation by sputtering remain in the thin film formed on the wafer or on the thin film, the resistance value changes at the remaining part, causing disconnection, short circuit, etc. in the case of a product. Since a problem occurs or a portion where particles remain is convex, a process after film formation (for example, Chemical
Mechanical Polishing (CM
P), etc.) causes that part to be strongly shaved compared to other parts and particles to fall off, resulting in a recess similar to the shape of the particle. Again, when the resistance value changes and the product is made, disconnection, short circuit, etc. It causes problems. Furthermore, there is a problem that under normal etching conditions, etching is not performed properly as compared with other portions, and accurate patterning cannot be performed.

The mechanism of generation of these particles is as follows: When abnormal discharge occurs on the surface of a sputtering target during sputtering, and molten particles generated at that time are scattered and adhere to the wafer, or when they are re-adhered to the outer periphery of the sputtering target. There are several generation mechanisms such as the peeled film is peeled off by the thermal cycle by sputtering, and the peeled redeposited film piece is attached to the wafer.

If the thickness of the thin film on which the electrodes are formed is not good, and if the amount of particles generated is large,
This will reduce the yield of LSI and cause great damage to LSI manufacturers.

The same applies to the W film with respect to the in-plane uniformity of the film thickness of the thin film formed from the above sputtering target or the generation of particles. As a sputtering target for forming the W film, for example, Japanese Patent Application Laid-Open No. 5-93267. C: 50 ppm or less, O: 30 ppm or less, a relative density of 97% or more, and a sputtering target having a shape in which a crystal grain size is crushed in a certain direction, and W described in JP-A-5-222525. After pressing the powder to produce a compact having a relative density of 60% or more, the compact is heated to a temperature of 1400 ° C. or more in an atmosphere containing hydrogen to obtain a sintered body having a relative density of 90% or more. Method for producing a sputtering target by subjecting a sintered body to hot working at 1400 ° C or higher to obtain a relative density of 99% or higher -76771 No. Relative density of 99.5% or more described in Japanese, average particle size, such as the sputtering target is less than 200μm exceed 10 [mu] m W
Sputtering targets are known, but even if these conventional W sputtering targets are used to form films under predetermined sputtering conditions, the film thickness uniformity of the W film is currently limited to about 3%, Furthermore, the reduction of particles was not satisfactory.

In recent years, along with the high integration, high speed, and high reliability required of LSIs, there has been a demand for lower resistance of electrodes and wiring materials. Speaking of electrodes, silicide is changed to high purity metal. And shift. In the electrode portion of such an LSI, the uniformity of the specific resistance within the wafer surface, that is, the film thickness uniformity is an important point. Since the in-plane uniformity of the W film obtained by using the currently known sputtering target is about 3%, the in-plane uniformity of the film thickness tends to deteriorate more and more as the wafer size further increases. .

Further, reduction of particles generated from the sputtering target is also an important point. In particular, the size of particles considered to be generated by abnormal discharge is mostly particles having a particle size of 1 μm or more, and therefore, further reduction of the particles of 1 μm or more has been strongly demanded.

If these phenomena are not avoided, the yield in LSI mass production lines will be significantly reduced, and a large amount of loss will occur.

The present invention has been made to address such a problem, and improves the in-plane uniformity of the thickness of a W film formed on a large substrate having a size of, for example, 8 inches. An object of the present invention is to provide a W sputtering target and a manufacturing method thereof.

[0020]

In order to solve the above problems, the present inventors have made various studies on the crystal orientation, crystal plane, and film thickness uniformity of the target surface of a W sputtering target. By controlling the FWHM of), it is possible to reduce the in-plane uniformity of the W film formed on a Si wafer of 8 inch size or more, which could not be achieved in the past, to 1% or less. I found the knowledge to do.

That is, the sputtering target according to the first invention of the present application is characterized in that the half value width of the peak of the crystal plane (110) obtained by X-ray diffraction of the surface to be sputtered is 0.35 or less. . In the present invention, the crystal plane (110) of this sputtered surface
By setting the full width at half maximum of the above to be the above value or less, it is possible to improve the in-plane uniformity of the film thickness of the W film formed by using the sputtering target.

In the first aspect of the invention, it is preferable that, in addition to the full width at half maximum of the specific crystal plane (110), the variation is 30% or less. By setting this variation to be the above value or less, it is possible to further improve the in-plane uniformity of the thickness of the formed W film.

Further, the inventors of the present invention have controlled the specific crystal orientation ratio on the target surface to form a W film formed on a large wafer of, for example, 8 inches or more, which could not be achieved conventionally. It was found that it is possible to improve the in-plane uniformity of the film thickness and reduce the generation of particles.

When sputtering is performed using a conventional high-purity W sputtering target, regardless of film forming conditions,
The limit is about 3% uniformity. When the diameter is further increased, for example, in the case of a 12-inch wafer, 5
% Will increase. In order to further reduce such film thickness uniformity, the present inventors have found that the emission distribution angle of neutral particles and ions scattered from the W sputtering target is important, and this emission distribution is As a result of various studies on the angle, the crystal orientation ratio (110) / (200) of the crystal planes (110) and (200) obtained by X-ray diffraction of the sputtering target surface effectively acts on the film thickness uniformity. I found that.

Based on the above knowledge, the W sputtering target according to the second aspect of the present invention has a crystal orientation ratio (110) / (200) of the crystal planes (110) and (200) determined by X-ray diffraction of the surface to be sputtered. (200) is 0.1 to 6.5.

That is, in the present invention, by adopting the second invention, it becomes possible to improve the in-plane uniformity of the film thickness of the W film formed by using the W sputtering target.

Further, if plastic working is carried out when the W sputtering target is manufactured, a slip is generated on W by the plastic working. This slip has a specific slip plane and slip direction determined in each crystal structure. The slip is
Crystallographically, it occurs at or near the crystal plane where the atoms are most densely present. When a slip occurs, a fault-like step called a slip plane or slip band occurs on the crystal plane. On this slip surface (slip band), as the sputtering proceeds, irregularities are formed in a fault shape. The unevenness of the unevenness is further increased by continuing the sputtering, and when the unevenness of the unevenness is increased, the electric charge is concentrated in the convex portion, and the inventors found that abnormal discharge occurs, and this slip As a result of various studies, crystal planes (110), (200), (211), (22) obtained by X-ray diffraction of the surface to be sputtered.
0) and (310) crystal orientation ratio (211) / {(1
10) + (200) + (211) + (220) + (31
It has been found that 0)} has a favorable effect on abnormal discharge and further on particles.

Based on the above findings, the W sputtering target according to the third aspect of the present invention has a crystal plane (110), which is obtained by X-ray diffraction of the surface to be sputtered,
Crystal orientation ratio of (200), (211), (220) and (310) (211) / {(110) + (200) +
(211) + (220) + (310)} is 0.17 or less.

That is, by adopting the third aspect of the present invention, it is possible to reduce the particles of the W film formed by using the W sputtering target.

Furthermore, the W sputtering target according to the fourth aspect of the present invention is characterized in that X on the surface to be sputtered.
Crystal planes (110), (20 determined by line diffraction
0), (211), (220) and (310) have a crystal orientation ratio (110) / (200) of 0.1 to 6.5 and a crystal orientation ratio of (211) / {(110) + ( Two
00) + (211) + (220) + (310)} is 0.
It is characterized by being 17 or less.

That is, in the present invention, by adopting the fourth invention, it is possible to improve the in-plane uniformity of the film thickness of the W film formed by using the W sputtering target and further to reduce the particles. It will be possible.

Further, a high purity W which is another invention of the present invention.
The sputtering target is manufactured by pressure-sintering high-purity W powder, processing the obtained sintered body into a target shape, and then performing at least one of rotary polishing and polishing.
It is characterized in that finishing is carried out by carrying out polishing of one kind and further polishing of at least one kind of etching and reverse sputtering. By adopting the manufacturing method as an example, it is possible to manufacture a sputtering target having a half width value or less defined in the present invention.

Further, in the production method of the present invention, in pressure sintering, when pressure is applied by a hot press, the temperature is raised to a maximum sintering temperature at a heating rate of 2 to 5 ° C./min, and then 1450. It is preferable to have an intermediate sintering step of holding at ˜1700 ° C. for 1 hour or more. By adopting this intermediate sintering process as an example, it becomes possible to manufacture a sputtering target having a value of variation in full width at half maximum defined in the present invention or less.

The structure of each invention will be described in detail below.

[0035]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, modes for carrying out the present invention will be described.

First, in the W sputtering target of the present invention, the half width of the peak of the crystal plane (110) determined by X-ray diffraction of the surface to be sputtered is 0.35 or less.

By using the sputtering target as described above, it becomes possible to improve the film thickness uniformity. That is, for example, when a W film is formed on a Si wafer having a size of 8 inches or more by a sputtering method using a W sputtering target, the film thickness uniformity of the formed W thin film is improved, and the resistivity distribution in the wafer surface is improved. It is possible to suppress variations.

When sputtering is performed using a conventional high-purity W sputtering target, regardless of the film forming conditions.
The limit is about 3% uniformity. When the diameter is further increased, for example, in the case of a 12-inch wafer, 5
% Will increase.

The present inventors have found that in order to further improve the film thickness uniformity, the emission distribution angle of neutral particles and ions scattered from the W sputtering target is important. As a result of various studies on
It was found that the half-value width of the peak of the crystal plane (110) determined by X-ray diffraction on the surface of the sputtering target is 0.35 or less effectively acts on the film thickness uniformity.

In general, the body-centered cubic (BC
The crystal planes of the C) structure are (110), (200),
There are several types of crystal planes such as (211), (220), (310). Among them, (110) is the densest surface of the BCC structure, there are few gaps in the crystal lattice, it is difficult for rare gases such as Ar atoms to be taken into the crystal lattice during sputtering, and it is considered that the sputtering rate is the highest. To be JCP
DS (Powder Diffraction Standards Joint Committee: Joint Comm
ittee on Powder Diffracti
It can also be understood from the fact that the crystal plane (110) also shows the main peak value in the on Standards card.

The surface of the sputtering target is usually subjected to mechanical polishing such as lathe processing, rotary polishing and polishing to finish the surface state of the sputtering target. However, internal strain is generated on the surface of the target due to machining, and the target is normally used in this state. As described above, since (110) has the highest sputtering rate, the smaller the internal strain contained in this crystal plane, the more stable the emission distribution angle. In the present invention, the internal strain contained in the (110) crystal plane is represented by a half width.

Generally, in the case of magnetron sputtering method,
It is said that the temperature of the sputtering target surface becomes 400 ° C. or higher as plasma is generated. In such a case, if the crystal plane on the sputter surface contains internal strain, the strain is released due to the thermal effect during sputtering, and a slight difference in the spatter emission distribution angle occurs. Therefore, when the half-value width of the peak of the crystal plane (110) obtained by X-ray diffraction on the target surface becomes 0.35 or more, the release of internal strain is promoted, and the emission distribution angle extremely changes, resulting in a film thickness. This will have a negative effect on the distribution.

Therefore, according to the present invention, the internal strain is small,
As a W sputtering target capable of obtaining a stable emission distribution angle, the half-value width of the peak of the crystal plane (110) determined by X-ray diffraction on the target surface was defined as 0.35 or less as in the present invention. . The full width at half maximum is preferably 0.3 or less, more preferably 0.2 or less, and further preferably 0.15 or less.

Furthermore, it is preferable that the variation of the half width of the crystal plane (110) on the surface of the sputtering target is within 30%.

This is because even if the full width at half maximum is within the range of the present invention on the surface of the sputtering target, if the variation of the entire crystal plane (110) is 30% or more, the emission distribution angle becomes uneven like the phenomenon described above. Is likely to occur,
This is because it becomes a factor that reduces the uniformity of the film thickness formed on the wafer. Therefore, the variation of the half width is specified to be 30% or less. This variation is 2
It is preferably 0% or less, more preferably 15% or less.

The W sputtering target of the second invention of the present invention has crystal planes (110) and (200) obtained by X-ray diffraction of the surface to be sputtered.
The crystal orientation ratio (110) / (200) of 0.1 to 6.
It is 5.

The present inventors have examined the relationship between the crystal plane (110) and other crystal planes for in-plane uniformity, and as a result,
It was found that the crystal orientation ratio with the crystal plane (200) greatly affects the in-plane uniformity, and this crystal orientation ratio (11
0) / (200) to control a specific range, namely 0.
The inventors have found that the in-plane uniformity of the W film to be obtained is improved by using the W sputtering target of 1 to 6.5 and completed the second invention.

In general, in the case of the magentron sputtering method, the target surface morphology hardly changes in the initial stage of using the W sputtering target, but when the amount used increases, only the portion with a strong magnetic field decreases with an extremely inclined angle. Then, a so-called maximum erosion part is formed.

In this case, in the initial stage of sputtering and in the state where the amount of use is increased, the emission distribution angle of the sputtered particles is largely changed as the shape of the sputtered surface is changed. Therefore, if the crystal orientation content ratio is out of the above range, the influence of the crystal orientation on the emission distribution angle of the sputtered particles due to the change in the shape of the sputtered surface becomes large compared to the influence on the emission distribution angle of the sputtered particles. Since the in-plane uniformity of the formed W film decreases as the sputtering progresses, the crystal orientation ratio (110) / (200) was set to 0.1 to 6.5. The crystal orientation content ratio is preferably in the range of 1 to 5, more preferably 2 to 4.

Further, if the crystal orientation ratio varies greatly over the entire W sputtering target, the emission distribution angle becomes uneven, and the height difference in the thickness of the formed W film becomes large, so the variation is 50. % Or less is preferable. The preferred range of this variation is 30
% Or less, more preferably 15% or less.

Next, the W sputtering target according to the third aspect of the present invention has crystal planes (110), (200), obtained by X-ray diffraction of the surface to be sputtered.
Crystal orientation ratio (211) / {(110) + (200) + (211) + of (211), (220) and (310)
(220) + (310)} is 0.17 or less, which is a tungsten sputtering target.

As described above, generally, on the slip surface (slip band) of the W sputtering target, as the sputtering progresses, unevenness is formed in a fault form. The unevenness of the unevenness is further increased by continuing the sputtering, and when the unevenness of the unevenness is increased, the electric charge is concentrated in the convex portion, and the inventors found that abnormal discharge occurs, and this slip As a result of various studies,
Crystal planes (110), (200), (211), (220) obtained by X-ray diffraction of the surface to be sputtered
And (310) crystal orientation ratio (211) / {(11
0) + (200) + (211) + (220) + (31
It has been found that the amount of particles in the obtained W film, especially the amount of particles of 1 μm or less can be reduced by controlling (0)} to obtain a W sputtering target having a specific range, that is, 0.17 or less.

This is because if the crystal orientation ratio is too large, the unevenness of the unevenness of the slip surface formed by sputtering will become large, resulting in the formation of a large convexity, so that the charge is more Since the concentration is concentrated and abnormal discharge is likely to occur and the amount of particles increases, the crystal orientation ratio (211) / {(110) + (2
00) + (211) + (220) + (310)} to 0.
It was set to 17 or less. The preferred range of the crystal orientation ratio is 0.15 or less, and more preferably 0.1 or less.

Further, if the crystal orientation ratio has a large variation in the W sputtering target as a whole, the emission distribution angle becomes uneven, and the height difference of the formed W film becomes large, so that the variation is 30. % Or less is preferable. The preferred range of this variation is 15
% Or less, and more preferably 10% or less.

Here, the full width at half maximum of the crystal plane, the crystal orientation ratio and their variations according to the present invention are values measured by the following method.

That is, as shown in FIG. 1, for example, from the center of a disk-shaped target (position 1) and the center of four straight lines that evenly divide the circumference through the center to the outer circumference. 90% distance position (positions 2-9) and 50 from center
From the positions (positions 10 to 17) at a distance of%, test pieces having a length of 15 mm and a width of 15 mm are collected. The crystal planes and crystal orientations of these 17 test pieces were measured, and the average value of these was taken as the crystal plane and crystal orientation ratio of the present invention. For the crystal plane, the full width at half maximum is calculated from the peak obtained by X-ray diffraction. The full width at half maximum is the ratio of the width at the height of 1/2 of the peak obtained by X-ray diffraction to the height of the peak. Each value is the average of the values measured 10 times or more at each location. The crystal orientation is the peak intensity value obtained by X-ray diffraction. An X-ray diffractometer (XRD) manufactured by Rigaku Co. was used as the X-ray diffractometer.
The measurement conditions are shown below.

<Measurement conditions> X-ray: Cu, k-α1, 50
kV, 100 mA, vertical goniometer, divergence slit: 1 deg, scattering slit: 1 deg, light receiving slit: 0.15 mm, scan mode: continuous, scan speed: 1 ° / min, scan step: 0.01 °, scan axis 2θ / Θ, measurement angle: 38 ° to 42 °

The chart for obtaining the half width of X-ray diffraction shows that 10000 cps is 11 mm and the scanning angle is 1 °.
Is based on a scale (scale) having a length of 23 mm. If a chart that is not this standard is used, the half-width is calculated using a chart that has been modified in accordance with this standard.

Furthermore, the variation of the crystal plane as the entire target surface is calculated from the maximum value and the minimum value of the crystal plane obtained from the above 17 test pieces, {(maximum value-minimum value)
/ (Maximum value + minimum value)} × 100.

The relative density of each of the W sputtering targets of the present invention is preferably 99% or more.

If the relative density is too low, the amount of particles generated increases, so the above range is set. This relative density is preferably 99.5% or more, more preferably 99.7% or more.

The above-mentioned relative density is a value measured by a conventional Archimedes method.

The W sputtering target of the present invention is
It may be contained as long as the amount of impurities is similar to that of a sputtering target made of a normal high-purity metal material. However, if the content of impurities is too large, the characteristics may be deteriorated, for example, the leak current is increased or the specific resistance is increased.

Therefore, the sputtering target of the present invention is made of iron (Fe), nickel (N
i), chromium (Cr), copper (Cu), aluminum (A
l), sodium, (Na), potassium (K), uranium (U), and thorium (Th) total content is 100.
It is preferable to configure with high purity W which is not more than ppm.

In other words, Fe, Ni, Cr, Cu,
A value obtained by subtracting the total amount of each content (% by mass) of Al, Na, K, U, and Th from 100% [100- (Fe + Ni + C
r + Cu + Al + Na + K + U + Th)] is 99.99.
It is preferable to use high purity W of not less than%.

The W sputtering target of the present invention is
It is preferable that the backing plate made of Cu, Al, or an alloy thereof be joined and integrated to be used.
For joining with the backing plate, a conventionally known joining method such as diffusion joining or brazing can be applied.

The W sputtering target of the present invention is
For example, it can be manufactured as follows.

For example, the first manufacturing method is a method using a hot press.

First, the high-purity W powder is pulverized by a ball mill or the like to obtain high-purity W powder with few skeleton particles. This high-purity W powder is filled in a carbon mold or the like that matches the intended target size, and pressure-sintered by hot pressing.
Since the high-purity W powder containing a large number of skeleton particles does not completely sinter to the inside of the skeleton particles even when pressure-sintered, a powder having a small number of skeleton particles is used as much as possible.

In the above pressure sintering step, before the temperature is raised to the maximum sintering temperature, for example, 1150 ° C. to 145 ° C.
It is preferable to perform a degassing treatment of heating at a temperature of 0 ° C. for at least 1 hour or more. This is to remove adsorbed oxygen and other impurity elements adhering to the raw material powder. The degassing atmosphere is preferably in a vacuum (1 Pa or less) or H ₂ atmosphere.

After performing such degassing treatment, heating is performed at a predetermined intermediate sintering temperature, for example, in a vacuum atmosphere of 1 Pa or less while applying a pressure of 20 MPa or more and sintering.

Here, before reaching the intermediate sintering temperature, the temperature rising rate is 2 ° C./min to 5 ° C./min, the intermediate sintering temperature 1
It is preferable to hold at a temperature of 450 ° C to 1700 ° C for 1 hour or more.

By carrying out such an intermediate sintering step, it is possible to improve the temperature uniformity of the sintered body and remove the voids or voids contained in the sintered body. Furthermore, in this intermediate sintering step, it is possible to bring the variation in the half-value width of the crystal plane (110) within the variation range defined in the present invention.

Then, after carrying out the intermediate sintering step, the temperature is further raised to the maximum sintering temperature to carry out the final sintering. The maximum sintering temperature is preferably 1900 ° C or higher. The holding time of such maximum sintering temperature is preferably 5 hours or more.

Cooling after the final sintering step is carried out, for example, by removing the pressure that was applied and cooling rate 10
It is preferable to cool at not less than ° C / min. Further, the pressure-sintered sintered body is further subjected to hot isostatic pressing (HI
P) You may process. HIP processing temperature is from 1400 ° C
It is preferable that the pressure is 1800 ° C. and the pressure is 150 MPa or more. By performing such HIP processing, it becomes possible to obtain a denser sintered body.

By subjecting the above-mentioned sintered body to heat treatment in a vacuum or in a hydrogen (H ₂ ) atmosphere at 1000 to 1300 ° C. for 1 hour or more, the half width becomes smaller, and a W sputter target having a more preferable half width is obtained. It is preferable to perform this heat treatment because it becomes easier to obtain.

As another manufacturing method, after hot isostatic pressing (CIP) treatment, HIP treatment is performed, and then hydrogen sintering is performed, and the obtained sintered body is hot rolled or hot forged. Good.

As another manufacturing method, HIP processing may be performed.

After the above HP or HIP treatment, it is also possible to carry out further hydrogen sintering, and then hot forging and hot rolling.

As another manufacturing method, a manufacturing method by CVD using WF ₆ / H ₂ gas or the like may be used. It can also be manufactured by sputtering, ion plating, thermal spraying, or vapor deposition.

The target material thus obtained is machined into a predetermined target shape.

Next, the obtained target material is subjected to the following surface finishing, and a crystal plane (1
A target having a half width of 10) within the range of the present invention is obtained.

First, in the present invention, the surface to be sputtered is subjected to at least one of rotary polishing and polishing. In particular, it is preferable to perform rotary polishing and then polish. The surface roughness in this case is preferably 1 μm or less in terms of arithmetic average roughness (Ra).

In the present invention, after the above polishing, etching such as wet etching or dry etching or surface treatment such as reverse sputtering is further performed. The surface roughness in this case is preferably 0.5 μm or less in terms of arithmetic average roughness (Ra). Potassium ferricyanide (potassium red blood) or the like can be used as an etching solution used for wet etching.
As an etching gas used for dry etching, a CF ₄ / O ₂ mixed gas or the like can be used.

In the present invention, it is possible to remove the internal strain accumulated in the crystal plane by the mechanical processing by applying the finishing processing by the above-mentioned polishing and to bring the internal strain within the range of the half width defined in the present invention. .

Next, the crystal orientation ratio (110) / (20
A method of using a hot press will be described as a method of producing the W sputtering target of the second invention which defines 0).

First, the high-purity W powder is pulverized in an argon (Ar) atmosphere or a hydrogen atmosphere by, for example, a ball mill for 24 hours or more to obtain high-purity W powder with few skeleton particles.

This high-purity W powder is filled in a carbon mold or the like suitable for the intended target size, and pressure-sintered by hot pressing. Since the high-purity W powder containing a large number of skeleton particles does not completely sinter to the inside of the skeleton particles even when pressure-sintered, a powder having a small number of skeleton particles is used as much as possible. Further, it is preferable to use the W powder having an oxygen content of 2000 ppm or less. This is because if the amount of oxygen is too large, the sintering does not completely proceed to the inside and a sintered body having a predetermined density cannot be obtained.

In the pressure sintering step described above, before the temperature is raised to the maximum sintering temperature, for example, 1150 ° C. to 145 ° C.
It is preferable to perform a degassing treatment of heating at a temperature of 0 ° C. for at least 1 hour or more. This is to remove adsorbed oxygen and other impurity elements adhering to the raw material powder. The degassing atmosphere is preferably in a vacuum (1 Pa or less) or H ₂ atmosphere.

After performing such degassing treatment, intermediate sintering is carried out at a predetermined intermediate sintering temperature, for example, heating and sintering under a vacuum atmosphere of 1 Pa or less while applying a pressure of 20 MPa or more.

Here, it is preferable to perform the step of releasing the pressure at the stage when the predetermined pressure is reached during the intermediate sintering and pressurizing it again to the predetermined pressure at least 5 times or more. It is possible to control the pressurizing-releasing-pressurizing process so as to improve the density at the sintering stage in the intermediate sintering process and to control the orientation of the crystal orientation intended in the second invention of the present invention. Become.

Here, before reaching the intermediate sintering temperature, the temperature rising rate is 2 ° C./min to 5 ° C./min, the intermediate sintering temperature 1
It is preferable to hold at a temperature of 450 ° C to 1700 ° C for 1 hour or more. By performing such an intermediate sintering step, it is possible to improve the temperature uniformity of the sintered body and remove the voids or voids contained in the sintered body. Furthermore, in this intermediate sintering step, the crystal orientation ratio (110) / (2
It is possible to make the variation of (00) within the range of the variation specified in the present invention.

Then, after carrying out the intermediate sintering step, the temperature is further raised to the maximum sintering temperature to carry out the final sintering. The maximum sintering temperature is preferably 1900 ° C or higher. The holding time of such maximum sintering temperature is preferably 5 hours or more.

Cooling after the highest sintering step is carried out, for example, by removing the pressure applied and cooling rate 10
It is preferable to cool at not less than ° C / min. Further, the pressure-sintered sintered body is further subjected to hot isostatic pressing (HI
P) You may process. HIP processing temperature is from 1400 ° C
It is preferable that the pressure is 1800 ° C. and the pressure is 150 MPa or more. By performing such HIP processing, it becomes possible to obtain a denser sintered body.

The above sintered body is further subjected to hot working, or at 2000 ° C. in a hydrogen (H ₂ ) atmosphere.
By performing the heat treatment as described above, the crystal orientation ratio (1
It is preferable to perform this hot working or heat treatment because it is easy to obtain a W sputter target in which 10) / (200) is within the range of variation defined by the present invention. Here, the hot working is hot working such as hot forging or hot rolling, and the hot working condition is 1 in an H ₂ atmosphere.
After holding at 000 to 1400 ° C for 1 hour, processing rate 30%
It is preferable to perform the following.

As another manufacturing method, after hot isostatic pressing (CIP) treatment, HIP treatment is performed, and then hydrogen sintering is performed, and the obtained sintered body is hot rolled or hot forged. Good.

As another manufacturing method, HIP processing may be performed.

After the above HP or HIP treatment, it is also possible to carry out further hydrogen sintering, and then hot forging and hot rolling.

Next, the crystal orientation ratio (211) / {(11
0) + (200) + (211) + (220) + (31
0)} is defined as a method for producing the W sputtering target of the third invention, using a hot press.

First, the high-purity W powder is crushed in an argon (Ar) atmosphere or a hydrogen atmosphere by, for example, a ball mill for 24 hours or more to obtain high-purity W powder with few skeleton particles.

This high-purity W powder is filled in a carbon mold or the like suitable for the intended target size, and pressure-sintered by hot pressing. The high-purity W powder containing a large number of skeleton particles does not completely sinter to the inside of the skeleton particles even if pressure-sintered, so use as little powder as possible. Further, it is preferable to use the W powder having an oxygen content of 2000 ppm or less. This is because if the amount of oxygen is too large, the sintering does not completely proceed to the inside and a sintered body having a predetermined density cannot be obtained.

In the pressure sintering step described above, before the temperature is raised to the maximum sintering temperature, for example, 1150 ° C. to 145 ° C.
It is preferable to perform a degassing treatment of heating at a temperature of 0 ° C. for at least 1 hour or more. This is to remove adsorbed oxygen and other impurity elements adhering to the raw material powder. The degassing atmosphere is preferably in a vacuum (1 Pa or less) or H ₂ atmosphere.

After carrying out such degassing treatment, intermediate sintering is carried out by heating at a predetermined intermediate sintering temperature, for example, in a vacuum atmosphere of 1 Pa or less while applying a pressure of 20 MPa or less and sintering. This is because it is difficult to obtain a high-density W sputtering target when the applied pressure is too large.

Here, it is preferable that the step of releasing the pressure at the stage of reaching the predetermined pressure during the intermediate sintering and pressurizing to the predetermined pressure again at least 5 times or more. It is possible to control the pressurizing-releasing-pressurizing process so as to improve the density at the sintering stage in the intermediate sintering process and to control the orientation of the crystal orientation intended in the second invention of the present invention. Become.

Before reaching the intermediate sintering temperature, the temperature rising rate is 2 ° C./min to 5 ° C./min, the intermediate sintering temperature is 1
It is preferable to hold at a temperature of 450 ° C to 1700 ° C for 1 hour or more.

By carrying out such an intermediate sintering step, it is possible to improve the temperature uniformity of the sintered body and remove the voids or voids contained in the sintered body.

After carrying out this intermediate sintering step, the temperature at the time of sintering is continuously lowered to a temperature of 800 to 1000 ° C., and a pressure of 40 MPa or more is set to 1 MPa /
The pressure is rapidly applied at a pressing rate of min (10 ton / min) or more, the temperature is further raised to the maximum sintering temperature, and the final sintering is performed. Here, if the temperature to be lowered is too low, the sintered body will be cracked by the subsequent rapid pressurization, and conversely if the temperature to be lowered is too high, the strain contained in the sintered body will be remarkably released. This is because it becomes difficult to obtain a predetermined crystal orientation ratio. In addition, the abrupt pressurization accelerates the sliding effect by abruptly pressurizing in a state where the sintering has progressed in the intermediate sintering step (for example, a sintering density of 95% or more), and a predetermined crystal orientation ratio is set. To get it.

The maximum sintering temperature after this intermediate sintering step is 1
It is preferably 900 ° C or higher. The holding time of such maximum sintering temperature is preferably 5 hours or more. this is,
This is because it is difficult to obtain a sintered body having a predetermined density and crystal orientation ratio if the maximum sintering temperature is too low or if the sintering time is too short.

Cooling after the highest sintering step is carried out, for example, by removing the pressure which has been applied and cooling rate 10
It is preferable to cool at not less than ° C / min. Further, the pressure-sintered sintered body is further subjected to hot isostatic pressing (HI
P) You may process. HIP processing temperature is from 1400 ° C
It is preferable that the pressure is 1800 ° C. and the pressure is 150 MPa or more. By performing such HIP processing, it becomes possible to obtain a denser sintered body.

Next, the crystal planes (110), (200),
The crystal orientation ratio (110) / (200) of (211), (220) and (310) is 0.1 to 6.5, and the crystal orientation ratio (211) / {(110) + (200) +.
The manufacturing method of the W sputtering target which is the fourth invention of the present invention in which (211) + (220) + (310)} is 0.17 or less can be manufactured by appropriately selecting the above manufacturing method. is there.

Next, the obtained target material is surface-finished, and the surface-finished W sputtering target of the present invention is used by being bonded and integrated with a backing plate made of Cu, Al, or an alloy thereof. Is preferred. For joining with the backing plate, a conventionally known joining method such as diffusion joining or brazing can be applied.

The brazing is preferably carried out using a known In-based or Sn-based bonding material. Further, the temperature at the time of diffusion bonding is preferably 600 ° C. or lower when bonding to an Al backing plate. This is A
This is because the melting point of 1 is 660 ° C.

By the above manufacturing method, the high purity W of the present invention is obtained.
It becomes possible to obtain a sputtering target.

The above manufacturing method is an example for obtaining the W sputtering target of the present invention, and the manufacturing method is not limited to any manufacturing method as long as the W sputtering target within the scope of the present invention can be obtained. Absent.

The W sputtering target of the present invention is used for forming electrodes and / or wirings of electronic parts represented by semiconductor elements and liquid crystal display elements.

[0116]

EXAMPLES Next, specific examples of the present invention will be described.

Example 1 A high-purity W powder was prepared, and the high-purity W powder was filled in a carbon mold and set in a hot press machine. Then, degassing treatment was performed at 1250 ° C. for a holding time of 3 hours in a vacuum atmosphere of 1 Pa or less. Next, while applying a pressure of 30 MPa in a vacuum atmosphere of 1 Pa or less from the degassing temperature, the temperature was raised at a temperature rising rate described in the column of the intermediate sintering step in Table 1, and the temperature and the holding time described in the column were set. Intermediate sintering was performed at. After the intermediate sintering step, the maximum sintering temperature was maintained at 1900 ° C. for 5 hours, and W sintered bodies as respective target materials were produced.
For cooling after sintering, the atmosphere was replaced with Ar, and 10 ° C / m
It was carried out at a cooling rate of in.

The W sintered body thus produced was machined to a desired target size (diameter Φ300 × thickness 5 mm). After rotary polishing the target surface,
The finishing process described in 1. was applied. Several types of W sputtering targets were obtained by brazing and joining the obtained sputtering target to a Cu backing plate with an In-based brazing material.

The crystal plane of the target surface was analyzed by an X-ray diffractometer (XRD manufactured by Rigaku Co., Ltd.), and the crystal plane (110)
The full width at half maximum of the peak and its variation were measured. The results are also shown in Table 1.

In Table 1, No. The targets of Nos. 14 to 16 were subjected to heat treatment at 1200 ° C. for 2 hours in vacuum after the W sintered body was manufactured.

The amount of impurities (Fe, N
i, Cr, Cu, Al, Na, K, U, Th total amount)
Was 10 ppm or less.

Sputtering method: magnetron sputtering, back pressure: 1 × 10 −5 Pa, output D
C: 2 kW, Ar: 0.5 Pa, sputtering time: 5 mi
A W film was formed on an 8-inch Si wafer substrate under the condition of n. In order to measure the film thickness uniformity of the obtained W film, the film thickness at each location where the diameter of the substrate was measured at 5 mm intervals from the end was measured, and the maximum value and the minimum value were calculated from the obtained values. The value was calculated based on the following equation, film thickness uniformity = {(maximum value−minimum value) / (maximum value + minimum value)} × 100. The results are shown together in Table 1.

[0123]

[Table 1]

As is clear from Table 1, a W sputtering target having a half width of the peak of the crystal plane (110) obtained by X-ray diffraction of the surface to be sputtered within the scope of the present invention, and further the crystal plane ( The W sputtering target having the variation of 110) within the range of the present invention is superior in film thickness uniformity as compared with the comparative example.

(Example 2) A high-purity W powder was prepared, and the high-purity W powder was filled in a carbon mold and set in a hot press machine. Then, the intermediate sintering step in Table 2 was performed. The temperature was raised at a heating rate, and the intermediate sintering was performed at the temperature and the holding time shown in the same column. After the intermediate sintering step, 1
In a vacuum atmosphere of Pa or less, a maximum sintering temperature of 1900 ° C. was maintained for 5 hours at a pressure of 30 MPa to obtain a W sintered body.
Then, the W sintered body was treated with HIP at 1800 ° C. for 5 hours under a pressure of 180 MPa to prepare a W sintered body as a target material.

The W sintered body thus produced was machined to a desired target size (diameter Φ300 × thickness 5 mm), the target surface was rotary-polished, and then the finishing process shown in Table 2 was applied. Several kinds of W sputtering targets were obtained by brazing and joining the obtained sputtering target to a Cu backing plate with an In-based brazing material.

The full width at half maximum and the variation of the obtained W sputtering target were measured under the same conditions as in Example 1. The results are also shown in Table 2.

The amount of impurities (Fe, N
i, Cr, Cu, Al, Na, K, U, Th total amount)
Was 10 ppm or less.

Using each of the W sputtering targets thus prepared, a W film was formed on an 8-inch Si wafer substrate under the same conditions as in Example 1, and
The film thickness uniformity of the obtained W film was measured. The results are shown together in Table 2.

[0130]

[Table 2]

As is clear from Table 2, the W sputtering target having the half width of the peak of the crystal plane (110) obtained by X-ray diffraction of the surface to be sputtered within the scope of the present invention, and further the crystal plane ( The W sputtering target having the variation of 110) within the range of the present invention is superior in film thickness uniformity as compared with the comparative example.

(Example 3) A high-purity W powder was prepared, and this high-purity W powder was CIP-sintered, and then continuously heated at 1600 ° C for 5 hours.
HIP treatment is performed under conditions of time and pressure of 150 MPa,
A sintered body having a density of 96% was obtained. Then, in a hydrogen atmosphere, 1
After holding for 0 hour, hot rolling was performed at 2200 ° C. in a hydrogen atmosphere to obtain a sintered body as a target material.

The W sintered body thus produced was machined to a desired target size (diameter Φ300 × thickness 5 mm), the target surface was rotary-polished, and then the finishing process shown in Table 3 was applied. Several kinds of W sputtering targets were obtained by brazing and joining the obtained sputtering target to a Cu backing plate with an In-based brazing material.

The full width at half maximum and the variation of the obtained W sputtering target were measured under the same conditions as in Example 1. The results are also shown in Table 3.

The impurity amount (Fe, N
i, Cr, Cu, Al, Na, K, U, Th total amount)
Was 10 ppm or less.

Using each of the W sputtering targets thus produced, a W film was formed on an 8-inch Si wafer substrate under the same conditions as in Example 1, and
The film thickness uniformity of the obtained W film was measured. The results are shown together in Table 3.

[0137]

[Table 3]

As is clear from Table 3, the W sputtering target having the half width of the peak of the crystal plane (110) obtained by X-ray diffraction of the surface to be sputtered within the scope of the present invention, and further the crystal plane ( The W sputtering target having the variation of 110) within the range of the present invention is superior in film thickness uniformity as compared with the comparative example.

(Example 4) Using a CVD apparatus, a W sintered body was obtained under a predetermined condition with source gas: WF ₆ and H ₂ .

The W sintered body thus produced was machined to a desired target size (diameter Φ300 × thickness 5 mm), the target surface was rotary-polished, and then the finishing process shown in Table 4 was applied. Several kinds of W sputtering targets were obtained by brazing and joining the obtained sputtering target to a Cu backing plate with an In-based brazing material.

The full width at half maximum and the variation of the obtained W sputtering target were measured under the same conditions as in Example 1. The results are also shown in Table 4.

The amount of impurities (Fe, N
i, Cr, Cu, Al, Na, K, U, Th total amount)
Was 10 ppm or less.

Using each of the W sputtering targets thus produced, a W film was formed on an 8-inch Si wafer substrate under the same conditions as in Example 1, and
The film thickness uniformity of the obtained W film was measured. The results are shown together in Table 4.

[0144]

[Table 4]

As is clear from Table 4, the W sputtering target having the half width of the peak of the crystal plane (110) obtained by X-ray diffraction of the surface to be sputtered within the scope of the present invention, and further the crystal plane ( The W sputtering target having the variation of 110) within the range of the present invention is superior in film thickness uniformity as compared with the comparative example.

Next, specific examples of the present invention in which the crystal orientation ratio is defined will be described.

Example 5 High-purity W powder was prepared, and the high-purity W powder was filled in a carbon mold and set in a hot press machine. Then, in a vacuum atmosphere of 1 Pa or less, degassing treatment was performed at a heat treatment temperature shown in Table 5 for a holding time of 3 hours. Then, in a vacuum atmosphere of 1 Pa or less from the degassing temperature, the pressure is increased from normal pressure to 30 M at the number of pressurizations shown in Table 5.
After repeating the pressurization and depressurization up to the pressure of Pa, the temperature was raised to the intermediate sintering temperature shown in Table 5 at a heating rate of 2 ° C./min, and then 2
Held for hours.

After the intermediate sintering, the temperature was raised to 1900 ° C. and the final sintering was performed for 5 hours. For cooling after sintering, the atmosphere was replaced by Ar, and the temperature was cooled to room temperature at the cooling rate shown in Table 5.
A W sintered body was obtained. A part of the obtained sintered body was further subjected to HIP treatment (180 MPa, 1800) as shown in Table 5.
℃), hot forging at 1600 ℃ (working rate 20%, 15
%) And hydrogen annealing at 1600 ° C.

For each W sintered body obtained by each of the above production methods,
Desired target size (diameter 300 mm, thickness 5 mm)
After machine processing, the target surface was polished by a conventional method to obtain a sputtering target. The obtained sputtering target was placed on a Cu backing plate with In.
Several types of W sputtering targets were obtained by brazing and joining with a system-based brazing material (Samples 101 to 1).
18).

The amount of impurities (Fe, N
i, Cr, Cu, Al, Na, K, U, Th total amount)
Was 10 ppm or less.

[0151]

[Table 5]

The relative density of the obtained W sputtering target was measured. The results are shown in Table 6. The crystal plane of the target surface is an X-ray diffractometer (XR manufactured by Rigaku Co., Ltd.
The crystal planes (110) and (2)
The crystal orientation ratio of (00) (110) / (200) and its variation were measured. The results are shown in Table 6.

Further, using each W sputtering target, sputtering method: magnetron sputtering, back pressure: 1 × 10 −5 Pa, output DC: 2 kW, A
Under the conditions of r: 0.5 Pa and sputtering time: 5 min,
A W film was formed on an 8-inch Si wafer substrate. In order to measure the film thickness uniformity of the obtained W film, the film thickness at each location where the diameter of the substrate was measured at 5 mm intervals from the end was measured, and the maximum value and the minimum value were calculated from the obtained values. The following equation, film thickness uniformity = {(maximum value−minimum value) / (maximum value + minimum value)} × 1
The value was calculated based on the formula of 00. The results are also shown in Table 6.

[0154]

[Table 6]

As is clear from Table 6, the W sputtering target of the present invention has a high density, and the crystal orientation ratio (110) / (200) obtained by X-ray diffraction of the sputtered surface within the scope of the present invention is The W sputtering target it has, and further, the W sputtering target in which the variation of the crystal orientation ratio is within the range of the present invention is superior in the film thickness uniformity to the W sputtering target outside the range of the present invention.

Example 6 High-purity W powder was prepared, and this high-purity W powder was crushed by a ball mill in an Ar atmosphere for the crushing time shown in Table 7. The obtained W powder was filled in a carbon mold and set in a hot press machine. And 1
Degassing treatment was performed at a heat treatment temperature and a holding time shown in Table 7 in a vacuum atmosphere of Pa or less. Next, in the vacuum atmosphere of 1 Pa or less as the first pressure from the degassing temperature,
The pressure was increased to 10 MPa, the temperature was raised to the intermediate sintering temperature shown in Table 7 at a temperature rising rate of 2 ° C./min, and the temperature was maintained for 2 hours. After the intermediate sintering, the obtained W sintered body was once cooled to the cooling temperature shown in Table 7. The temperature of the once cooled W sintered body is increased from the cooling temperature to the pressure shown in Table 7 as the second pressurization rate by 2 ° C./min.
After the temperature was raised to the final sintering temperature shown in Table 7, the final sintering was carried out by holding for the holding time shown in Table 7. For cooling after sintering, the atmosphere was replaced with Ar and the temperature was cooled to room temperature at the cooling rate shown in Table 7 to obtain a W sintered body.

With respect to each W sintered body obtained by each of the above production methods,
Desired target size (diameter 300 mm, thickness 5 mm)
After machine processing, the target surface was polished by a conventional method to obtain a sputtering target. The obtained sputtering target was placed on a Cu backing plate with In.
Several types of W sputtering targets were obtained by brazing and joining with a system-based brazing material (Samples 119 to 1).
37).

The amount of impurities (Fe, N
i, Cr, Cu, Al, Na, K, U, Th total amount)
Was 10 ppm or less.

[0159]

[Table 7]

The relative density of the obtained W sputtering target was measured. The results are shown in Table 8. The crystal plane of the target surface was analyzed by an X-ray diffractometer (XRD manufactured by Rigaku Co., Ltd.), and (110), (200), (211),
(220) and (310) crystal orientation ratio (211) /
{(110) + (200) + (211) + (220) +
(310)} and its variation were measured. The results are shown in Table 8.

Further, using each W sputtering target, sputtering method: magnetron sputtering, back pressure: 1 × 10 −5 Pa, output DC: 2 kW, A
Under the conditions of r: 0.5 Pa and sputtering time: 5 min,
A W film was formed on an 8-inch Si wafer substrate. Particles of 1 μm or more in the obtained W film were measured by a particle counter device (WN-3). The measurement result was an average value obtained by measuring 300 wafers. The results are also shown in Table 8.

[0162]

[Table 8]

As is clear from Table 8, the W sputtering target of the present invention has a high density, and the crystal orientation ratio (211) / {(110) obtained by X-ray diffraction of the surface to be sputtered within the scope of the present invention. + (200) + (21
1) + (220) + (310)}, and further, a W sputtering target in which the variation of the crystal orientation ratio is within the range of the present invention is 1
Generation of particles of μm or more is reduced, which is superior to W sputtering targets outside the scope of the present invention.

In the above embodiment, the crystal plane (110)
And (200) crystal orientation ratio (110) / (200)
And the crystal orientation ratio (211) / {(110) + (20
0) + (211) + (220) + (310)} have been individually described. However, a W sputtering target having a crystal orientation ratio satisfying both of them has the effect of improving both film thickness uniformity and particle reduction. Obtainable.

As described above, the W sputtering target of the present embodiment can improve the in-plane uniformity of the thickness of the W film formed on the large-sized substrate, and further reduce the generation of particles. It is possible.

Example 7 High-purity W powder was prepared, and this high-purity W powder was crushed by a ball mill in an Ar atmosphere for the crushing time shown in Table 9. The obtained W powder was filled in a carbon mold and set in a hot press machine. And 1
The degassing treatment was performed in a vacuum atmosphere of Pa or less at the heat treatment temperature and the holding time shown in Table 9. Next, after repeating the pressurization and depressurization from normal pressure to 30 MPa with the number of pressurizations shown in Table 9, then, from the degassing temperature, as the first pressurization, pressurizing to 10 MPa in a vacuum atmosphere of 1 Pa or less. Then, the temperature was raised to the intermediate sintering temperature shown in Table 9 at a temperature rising rate of 2 ° C./min and held for 2 hours. After the intermediate sintering, the obtained W sintered body was once cooled to the cooling temperature shown in Table 9. The W sintered body once cooled is heated from the cooling temperature to the pressure shown in Table 9 as the second pressurization at a heating rate of 2 ° C./min up to the final sintering and sintering temperature shown in Table 9, The holding time shown in FIG. 9 was maintained and the final sintering was performed. For cooling after sintering, the atmosphere should be Ar.
And was cooled to room temperature at the cooling rate shown in Table 9 to obtain a W sintered body.

For each W sintered body obtained by each of the above production methods,
Desired target size (diameter 300 mm, thickness 5 mm)
Was machined. After the surface of the target was rotary-polished, the finishing process shown in Table 9 was performed. By brazing the obtained sputtering target to a Cu backing plate with an In-based brazing material,
Several kinds of W sputtering targets were obtained (Sample 20)
1-210).

[0168]

[Table 9]

The relative density of the obtained W sputtering target was measured.

The crystal plane of the target surface was analyzed by an X-ray diffractometer (XRD manufactured by Rigaku Co., Ltd.), and the crystal plane (1
The full width at half maximum of the peak of 10) and its variation were measured. The results are also shown in Table 10.

Crystal planes (110) and (20)
The crystal orientation ratio of (0) (110) / (200) and its variation were measured. The results are also shown in Table 10.

Further, (110), (200), (21
1), (220) and (310) crystal orientation ratio (2
11) / {(110) + (200) + (211) + (2
20) + (310)} and its variation were measured.
The results are also shown in Table 10.

The amount of impurities (Fe, N
i, Cr, Cu, Al, Na, K, U, Th total amount)
Was 10 ppm or less.

Further, using each W sputtering target, sputtering method: magnetron sputtering, back pressure: 1 × 10 ⁻⁵ Pa, output DC: 2 kW, A
Under the conditions of r: 0.5 Pa and sputtering time: 5 min,
A W film was formed on an 8-inch Si wafer substrate. In order to measure the film thickness uniformity of the obtained W film, the film thickness at each location where the diameter of the substrate was measured at 5 mm intervals from the end was measured, and the maximum value and the minimum value were calculated from the obtained values. The following equation, film thickness uniformity = {(maximum value−minimum value) / (maximum value + minimum value)} × 1
The value was calculated based on the formula of 00. The results are shown together in Table 10. Further, particles having a particle diameter of 1 μm or more mixed in the obtained W film were measured with a particle counter device (WN-3). The measurement result is 30
The average value was obtained by measuring 0 wafers. The results are also shown in Table 10.

[0175]

[Table 10]

As is clear from Table 10, the W sputtering target of the present invention has a high density, and the full width at half maximum of the peak of the crystal plane (110) obtained by X-ray diffraction of the sputtered surface within the scope of the present invention is shown. The W sputtering target has, the W sputtering target having a variation in the crystal plane (110) thereof within the scope of the present invention, the W sputtering target having a crystal orientation ratio (110) / (200), and further, the variation in the crystal orientation ratio is the W sputtering target within the scope of the invention, crystal orientation ratio (211) / {(110) + (200) + (211) +
The W sputtering target having (220) + (310)}, and further, the W sputtering target having a variation in the crystal orientation ratio thereof within the range of the present invention has excellent film thickness uniformity and a particle size of 1 μm or more. Generation of particles is reduced.

[0177]

As is apparent from the above description, the high-purity W sputtering target of the present invention can improve the in-plane uniformity of the W film thickness. As a result, it is possible to improve the reliability when used as an electrode of a semiconductor device and the yield at the time of manufacturing the same.

Furthermore, the method for producing a high-purity W sputtering target according to the present invention makes it possible to obtain a W sputtering target capable of obtaining excellent in-plane uniformity of film thickness.

[Brief description of drawings]

FIG. 1 is a schematic view showing a half-value width of a target of the present invention and a seeding point of a test piece when measuring its variation.

[Explanation of symbols]

1-17 Test piece seeding point

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yoichiro Yabe             8 East Shinsugita-cho, Isogo-ku, Yokohama-shi, Kanagawa             Shiba Electronics Engineering Co., Ltd. (72) Inventor Takashi Ishigami             8th Shinsugita Town, Isogo Ward, Yokohama City, Kanagawa Prefecture             Ceremony company Toshiba Yokohama office (72) Inventor Takashi Watanabe             8th Shinsugita Town, Isogo Ward, Yokohama City, Kanagawa Prefecture             Ceremony company Toshiba Yokohama office (72) Inventor Hitoshi Aoyama             8th Shinsugita Town, Isogo Ward, Yokohama City, Kanagawa Prefecture             Ceremony company Toshiba Yokohama office (72) Inventor Yasuo Takasaka             8th Shinsugita Town, Isogo Ward, Yokohama City, Kanagawa Prefecture             Ceremony company Toshiba Yokohama office (72) Inventor Yukinobu Suzuki             8th Shinsugita Town, Isogo Ward, Yokohama City, Kanagawa Prefecture             Ceremony company Toshiba Yokohama office F-term (reference) 4K018 AA19 BA09 DA32 EA05                 4K029 BD02 DC03 DC09                 4M104 BB18 DD37 DD40 HH20

Claims (16)

[Claims] 1. The full width at half maximum of the peak of the crystal plane (110) determined by X-ray diffraction of the surface to be sputtered is 0.
The tungsten sputtering target is 35 or less. 2. The crystal plane (11) of the surface to be sputtered.
2. The tungsten sputtering target according to claim 1, wherein the variation in the half width of 0) is 30% or less. 3. The crystal orientation ratio (110) / (200) of the crystal planes (110) and (200), determined by X-ray diffraction of the surface to be sputtered, is 0.1 to 6.5. And a tungsten sputtering target. 4. The variation in the crystal orientation ratio (110) / (200) of the crystal planes (110) and (200) determined by X-ray diffraction of the surface to be sputtered is 50% or less. The tungsten sputtering target according to claim 3. 5. Crystal planes (110), (200), (21) obtained by X-ray diffraction of the surface to be sputtered.
1), (220) and (310) crystal orientation ratio (21
1) / {(110) + (200) + (211) + (22
0) + (310)} is 0.17 or less, a tungsten sputtering target. 6. Crystal planes (211), (110), (20) obtained by X-ray diffraction of the surface to be sputtered.
0), (211), (220) and (310) crystal orientation ratio (211) / {(110) + (200) + (21
The tungsten sputtering target according to claim 5, wherein the variation of (1) + (220) + (310)} is 30% or less. 7. Crystal planes (110), (200), (21) obtained by X-ray diffraction of the surface to be sputtered.
1), (220) and (310) crystal orientation ratio (11
0) / (200) is 0.1 to 6.5, and the crystal orientation ratio is (211) / {(110) + (200) + (21
1) + (220) + (310)} is 0.17 or less, The tungsten sputtering target characterized by the above-mentioned. 8. The variation of the crystal orientation ratio (110) / (200) of the crystal planes (110) and (200) determined by X-ray diffraction of the surface to be sputtered is 50% or less, and the crystal orientation ratio. (211) / {(110) +
8. The variation of (200) + (211) + (220) + (310)} is 30% or less.
The described tungsten sputtering target. 9. The tungsten sputtering target according to claim 1, which has a relative density of 99% or more. 10. The tungsten sputtering target according to claim 1, wherein the sputtering target is used for forming an electrode and / or a wiring of a semiconductor element. 11. The tungsten sputtering target according to claim 1, wherein the sputtering target is joined and integrated with a backing plate. 12. The sputtering target is finished by being subjected to at least one type of polishing such as rotary polishing and polishing, and further subjected to at least one type of etching and reverse sputtering. The tungsten sputtering target according to any one of claims 1 to 11. 13. The tungsten sputtering target according to claim 11, wherein the sputtering target is joined and integrated with the backing plate by diffusion joining or brazing. 14. The sputtering target is characterized in that the total content of iron, nickel, chromium, copper, aluminum, sodium, potassium, uranium and thorium as impurities is 100 ppm or less. 9. The tungsten sputtering target according to any one of 9 above. 15. High-purity tungsten powder is pressure-sintered, the obtained sintered body is processed into a target shape, and then at least one of rotary polishing and polishing is performed, and at least one of etching and reverse sputtering is performed. 15. The method for manufacturing a tungsten sputtering target according to claim 1, wherein the finish processing is performed by performing seeding. 16. Pressurized sintering is 1450 to 1700 after the temperature is raised at a temperature raising rate of 2 to 5 ° C./min in the step of raising the temperature to the maximum sintering temperature when pressure is applied by a hot press.
The method for producing a tungsten sputtering target according to claim 15, further comprising an intermediate sintering step of holding the temperature at 1 ° C. for 1 hour or more.