JP6677883B2 - Sputtering target and method of manufacturing sputtering target - Google Patents

Description

  The present invention relates to a sputtering target and a method for manufacturing the same.

  Recently, Si-based thin films having acid resistance and high transmittance have been used in various fields as, for example, protective films and insulating films. As a method of forming a thin film of the Si-based material, a method of performing sputtering in a gas atmosphere containing argon, oxygen, or nitrogen using a sputtering target using a Si alloy as a target material is known.

  As a sputtering target, one having a configuration in which a target material is sprayed on a surface of a base material to form a target material on the surface of the base material is known. As the shape of the base material, a flat plate type and a cylindrical type are known.

  Patent Literature 1 discloses a cylindrical substrate (columnar substrate), an intermediate layer formed on the outer peripheral surface of the substrate, and Cr, Ti, and Zr formed on the outer peripheral surface of the intermediate layer. A sputtering target comprising a target material (target layer) mainly containing a Si alloy containing at least one kind is described. However, there is no general description in Patent Document 1 regarding the content of a metal element such as Cr. The amount of a metal element such as Cr contained in the target material described in the example of Patent Document 1 is 4 to 6%.

  Patent Literature 2 discloses a columnar substrate (substrate), an intermediate layer formed on an outer peripheral surface of the substrate, and at least one kind selected from Cr, Ti, and Zr formed on an outer peripheral surface of the intermediate layer. And a target material (target layer) mainly composed of a Si alloy containing, and a portion of the target material separated from the interface with the intermediate layer by a certain distance, the concentration of a metal element such as Cr other than the target region. Sputtering targets with higher concentrations are described. However, there is no general description in Patent Document 2 regarding the content of a metal element such as Cr. The amount of a metal element such as Cr contained in the target material described in the example of Patent Document 2 is 3 to 5%.

Further, Patent Document 3 discloses that a composition for coating a target is made of 2 to 20% of Al, 25 to 45% of Si, and 45 to 45% of ZrSi ₂ by using a manufacturing method by thermal spraying (thermal spraying). Compositions containing 70% are described.

  Further, Patent Document 4 discloses that the silicon content is 70 to 97% by weight, and the balance substantially consists of a high melting point metal (Cr) silicide. )) And a high melting point metal silicide phase.

JP-A-5-86463 JP-A-5-86465 Japanese Patent No. 5154950 JP 2002-173765 A

  A sputtering target for forming a thin film of a Si-based material desirably has a thick target material in order to enable continuous film formation over a long period of time. In addition, in the case of a sputtering target, the surface of the target material is generally machined using a lathe in order to suppress occurrence of abnormal discharge during film formation by sputtering. It is also desired that cracking and chipping do not occur, that is, the target material has high mechanical strength. Further, it is desired that the production process of the sputtering target be simple.

However, the sputtering targets described in Patent Literatures 1 and 2 contain a small amount of Cr contained in the target material and have high brittleness. Therefore, unless an intermediate layer is provided, cracking or chipping occurs by machining. There is a problem that it becomes easier. According to the study of the present inventors, when a target material is formed by thermal spraying using a composition containing silicide such as ZrSi ₂ or CrSi ₂ described in Patent Documents 3 and 4, silicide has brittleness. Therefore, it has been found that when the thickness of the target material is increased, there is a problem that the target material is likely to be cracked or chipped during machining.

  Accordingly, an object of the present invention is to provide a sputtering target on which a target material having a high mechanical strength capable of being machined using a lathe is formed even if the thickness is large, and a method for manufacturing the same.

In order to solve the above problems, a sputtering target of the present invention includes a base material and a target material formed on a surface of the base material, wherein the target material contains a metal element M of 8 atomic% or more and 66 atomic% or more. Atomic percent or less, the balance has a composition consisting of Si and unavoidable impurities, and has a metal M phase and a metal Si phase. In X-ray diffraction, the (111) plane of the metal Si The ratio I _sum / I _Si × 100 between the integrated intensity I _Si of the peak and the sum I _sum of the integrated intensity of the peak of each silicide compound represented by M _x Si _y is not more than 10%.

  In the sputtering target of the present invention, the adhesion of the target material to the substrate and the mechanical strength are increased by the metal M phase present in the target material acting as a binder. For this reason, in the sputtering target of the present invention, it is possible to form a target material having high mechanical strength that can be machined even if the thickness is large.

  Further, in the sputtering target of the present invention, the content of the metal element M in the target material is in the range of 8 atomic% to 66 atomic%. Since the content of the metal element M is 8 atomic% or more, the adhesion of the target material to the base material is improved, the target material is hardly peeled off from the base material, and the mechanical strength of the target material is improved. In addition, cracks and chips are less likely to occur during machining. On the other hand, when the content of the metal element M exceeds 66 atomic%, a silicide compound which does not act as a binder is generated, and the mechanical strength of the target material is reduced.

Further, in the sputtering target of the present invention, in X-ray diffraction, the integrated intensity I _Si of the peak of the (111) plane of the metal _Si and the sum I _sum of the integrated intensity of the peak of each silicide compound represented by M _x Si _y are represented by ratio I _{sum /} I _Si × 100 is, have been limited to 10% or less, silicide compound because almost no in the target material, adhesion and mechanical strength to the substrate of the target material becomes high.

  In the sputtering target of the present invention, the target material preferably has an area ratio of the metal M phase in the cross section in the thickness direction of 5% or more. When the area ratio is 5% or more, the mechanical strength of the target material is further improved, and the target material is less likely to crack or chip when the sputtering target is transported or machined.

  In the sputtering target according to the present invention, it is preferable that the average value of the ratio between the major axis and the minor axis of the metal M phase in the cross section in the thickness direction of the target material is 2.0 or more. When the ratio of the length of the long axis to the short axis of the metal M phase is 2.0 or more, the mechanical strength is further improved and the target material is less likely to crack or chip when subjected to machining. Become.

In the sputtering target of the present invention, the target material preferably has a bending strength of 40 N / mm ² or more. If the transverse rupture strength is 40 N / mm ² or more, cracks are less likely to occur in the target material during film formation by machining or sputtering.

  In the sputtering target of the present invention, the target material preferably has a theoretical density ratio of 90% or more. When the theoretical density ratio is 90% or more, abnormal discharge hardly occurs during film formation by sputtering.

  In the sputtering target of the present invention, the content of the metal element M in each part of the target material is preferably within ± 3% of the average value X of the content of the metal element M in the entire target material. . If the range of the variation of the content of the metal element M is within ± 3% (that is, the composition is uniform), it is difficult for the concentration of electric charge to occur at the time of sputtering, and the abnormal discharge is hard to occur at the time of film formation by sputtering.

  In the sputtering target of the present invention, it is preferable that the metal element M is a high melting point metal element having a melting point higher than the melting point of Si. Since the melting point of the metal element M is higher than the temperature of the melting point of Si, the metal element M is not easily vaporized even during the production of the target material (during thermal spraying) or during film formation by sputtering, and the mechanical strength of the target material is stable. become. The refractory metal element is preferably at least one metal element selected from the group consisting of Co, Cr, Mo, Nb, Ta, Ti, W and Zr. This is because these metal elements have high chemical stability.

The method for manufacturing a sputtering target according to the present invention is directed to a sputtering target that performs thermal spraying on a substrate using a mixed powder containing a powder of a metal element M and a powder of a metal Si to form a target material on the surface of the substrate . In a manufacturing method, in a particle size distribution of each of the powder of the metal element M and the powder of the metal Si, a difference in particle diameter between D10 and D90 of the cumulative frequency is within 150 μm .

  In the method for manufacturing a sputtering target according to the present invention, since the powder of the metal element M is used as the raw material of the metal element M instead of the powder of the silicide compound of the metal element M, the metal Si phase and the metal M phase are formed on the surface of the base material. Can be formed. For this reason, it becomes possible to form a thick target material on the surface of the base material.

Powder powder and metal Si metal element M for use in the manufacturing method of the sputtering target of the present invention, it is preferable that the difference of the particle size of at D30 and D70 of the cumulative frequency is within 50μm in the particle size distribution of their respective . When the difference between the particle diameters is within the above range, the manner in which the powder flies during thermal spraying becomes uniform, and a target material having a uniform composition is easily generated.

As described above, according to the present invention, it is possible to provide a sputtering target in which a target material having a high mechanical strength capable of being machined using a lathe is formed on a surface of a base material, even if the thickness is large. Can be.
By using the sputtering target of the present invention, a thin film of a Si-based material can be continuously formed over a long period of time.
Further, by using the method for manufacturing a sputtering target of the present invention, it is possible to industrially stably manufacture a thick target material on the surface of a substrate.

3 is an elemental analysis image of a cross section in a thickness direction of a target material of a Si—Cr alloy sputtering target according to one embodiment of the present invention. It is a sectional photograph in the thickness direction of the target material of the Si-Cr alloy sputtering target which is one embodiment of the present invention. 4 is a measurement result of X-ray diffraction (XRD) of a target material of a Si—Cr alloy sputtering target according to one embodiment of the present invention. It is a perspective view which shows the sampling method of the test piece for bending strength measurement.

  The sputtering target of the present embodiment includes a base material and a target material formed on the surface of the base material. The thickness of the target material is generally at least 3 mm, preferably at least 5 mm. The upper limit of the thickness of the target material is generally 13 mm.

  As the substrate, a cylindrical substrate (backing tube) and a flat substrate (backing plate) can be used. As an example of the material of the base material, stainless steel (SUS) can be given. The surface of the substrate is preferably blasted. By using a substrate whose surface has been blasted, the adhesion between the substrate and the target material can be further improved.

In the sputtering target of the present embodiment, the target material contains the metal element M in a range of 8 atomic% to 66 atomic%, and the balance has a composition of Si and inevitable impurities. Preferably, the metal element M forms a metal M phase, and the Si forms a metal Si phase. The target material may contain an unavoidable compound. Here, the unavoidable impurities mean those that have been mixed in the raw material of the target material or those that have been unavoidably mixed into the target material during the production of the sputtering target. The unavoidable compound means a compound that is unavoidably generated during the production of a sputtering target. Examples of the unavoidable compound include a reaction product of a metal element M and Si constituting the target material (M _x Si _y : silicide compound) and a reaction product of the metal element M and / or Si and an unavoidable impurity. Can be.

In the X-ray diffraction, the target material also has a ratio I _sum between the integrated intensity I _Si of the peak of the (111) plane of the metal Si and the sum I _sum of the integrated intensity of the peak of each silicide compound represented by M _x Si _y. / I _Si × 100 is set to 10% or less. The sum I _sum of the integrated intensity of the peak of each silicide compound is the _sum of the integrated intensity of the peak having the highest intensity in the X-ray diffraction pattern of each silicide compound contained in the target material. For example, when the silicide compound is Cr silicide, the silicide compound represented by M _x Si _y includes Cr ₅ Si ₃ , CrSi, CrSi ₂ and Cr ₃ Si. The sum I _sum of the integrated intensities of the X-ray diffraction peaks of the Cr silicide compound is (411) plane of Cr ₅ Si ₃ , (210) plane of CrSi, (110) plane of CrSi ₂ and (210) plane of Cr ₃ Si. Is the sum of the integrated intensities of the respective diffraction peaks.

  It is preferable that the metal M phase and the metal Si phase in the target material form a layered structure (lamella structure) which is superposed on each other. The metal M phase preferably has a flat shape along the surface direction of the base material when viewed from a cross section in the thickness direction of the target material.

  The area ratio of the metal M phase in the cross section in the thickness direction is preferably 5% or more. The area ratio of the metal M phase means the ratio of the area occupied by the metal M phase to the area of the target material in the cross section in the thickness direction. The upper limit of the area ratio of the metal M phase is generally 70%.

  Further, it is preferable that the average value of the ratio of the major axis to the minor axis (long axis / short axis) of the metal M phase in the cross section in the thickness direction is 2.0 or more. The major axis of the metal M phase preferably extends in a direction parallel to the surface direction of the substrate. The upper limit for the length ratio between the major axis and the minor axis is generally 20.

The target material preferably has a bending strength of 40 N / mm ² or more. The theoretical density ratio is preferably 90% or more. The theoretical density ratio is a ratio (percentage) of the actual density of the target material to the theoretical density of the target material. Note that the theoretical density of the target material is a density assuming that the metal elements M and Si each form a single metal phase.

  In the target material, the content of the metal element M in each part of the target material is preferably within ± 3% of the average value X of the content of the metal element M in the entire target material. The average value X of the content of the metal element M is preferably an average value of the content of the metal element M measured at three or more locations on the target material.

  The metal element M preferably has a melting point in the range of 1300 to 3500 ° C. It is particularly preferable that the metal element M is a high melting point metal element whose melting point is higher than the melting point of Si (1412 ° C.). Examples of the high melting point metal element include Co, Cr, Mo, Ni, Nb, Ta, Ti, W and Zr.

Next, a method for manufacturing the sputtering target of the present embodiment will be described.
In the method for manufacturing a sputtering target according to the present embodiment, a target material is formed on the surface of the base material by performing thermal spraying on the base material using a mixed powder including a powder of the metal element M and a powder of the metal Si. .

  The ratio between the metal element M powder and the metal Si powder in the mixed powder is such that the content of the metal element M in the target material formed by spraying the mixed powder is in the range of 8 to 66 atomic%. It is. However, the ratio between the powder of the metal element M and the powder of the metal Si in the mixed powder and the ratio of the metal element M and the metal Si in the target material generally do not tend to match. This may be because the metal element M powder and the metal Si powder are scattered during thermal spraying. The amount of the metal element M powder and metal Si powder scattered during the thermal spraying varies depending on factors such as the particle diameter and density of the powder and the thermal spraying conditions. For this reason, the mixing ratio (preparation amount) of the metal element M powder and the metal Si powder in the mixed powder cannot be uniformly determined, but generally, M: Si = 5: 95 to 70:30 (atomic ratio). Range.

The average particle diameter (D50) of the metal element M powder and the metal Si powder used in the method of manufacturing a sputtering target is preferably in the range of 20 to 300 μm. When the average particle size is less than 20 μm, the powder is agglomerated, and when the average particle size is more than 300 μm, the particles become heavy, so that it becomes difficult to supply the powder to the sprayed portion.
It is preferable that the metal element M powder and the metal Si powder each have a narrow particle diameter distribution range. Specifically, the difference between the particle diameters of the metal element M powder and the metal Si powder at the cumulative frequency D10 and D90 in the respective particle size distributions is preferably within 150 μm. Further, it is preferable that the difference between the particle diameters at the cumulative frequencies D30 and D70 of the powder of the metal element M and the powder of the metal Si be within 50 μm.

Further, the powder of the metal element M and the powder of the metal Si preferably satisfy the following formula.
Formula: 0.10 <(D _M ² × ρ _M ) / (D _Si ² × ρ _Si ) <350
Here, _DM is the average particle diameter of the metal element M powder, ρ _M is the density of the metal element M powder, D _Si is the average particle diameter of the metal Si powder, ρ _Si Is the density of the metal Si powder.
When the above formula ^{_{(D M 2 × ρ M)}} / (D Si 2 × ρ Si) is further from 1, it is a difference in how to fly the powder in the spray, that the composition of the obtained target material distribution is generated There is.

  Next, the sputtering target of the present embodiment will be described with reference to a sputtering target in which the substrate is a SUS backing tube and the target material is a Si-Cr alloy using Cr as the metal element M.

  The target material of the Si—Cr alloy can be formed, for example, by spraying a mixed powder containing a Si powder and a Cr powder on the outer periphery of the backing tube by a plasma spraying method. When the mixed powder is introduced into the plasma generated by the plasma generation torch, the Si powder is softened and the Cr powder is also melted. The softened Si and the molten Cr are sprayed on the surface of the backing tube by the plasma and solidified on the surface. When the softened Si and the molten Cr are sprayed, the metal Si phase and the metal Cr phase are uniformly dispersed, and the respective metal phases are flattened and overlapped in a layered structure, that is, the metal Si phase and the metal A lamellar structure is generated by the Cr phase and solidified as it is to form the Si—Cr alloy target material.

As one embodiment, a sputtering target on which a Si-Cr alloy target material containing 33 atomic% of Cr was formed. An elemental analysis image of a cross section in the thickness direction of the target material of the sputtering target was measured by EPMA (field emission type electron beam probe). FIG. 1 shows the measurement results. FIG. 1 shows elemental analysis images of seven elements of Si, Cr, C, Fe, O, Mn, and Ni. Each element of Fe, Mn, and Ni is detected from SUS of the backing tube.
In the elemental analysis image of FIG. 1, the whiter the image, the higher the concentration of the element. Specifically, in the distribution image relating to Si, it is observed that the Si element is distributed in a white layer portion, and in the distribution image relating to Cr, it is observed that the Cr element is distributed in the white layer portion. From the elemental analysis image of the Si element and the Cr element in FIG. 1, it can be seen that the layers overlap each other (lamella structure) in the cross section in the thickness direction of the target material.

  The fact that the Si—Cr alloy target material has a lamellar structure will be described in more detail based on photographs taken with an electron microscope. FIG. 2 is a photograph of a cross section in the thickness direction of the Si—Cr metal alloy target material. In FIG. 2, a white portion represents a metal Cr phase, and a dark gray portion represents a metal Si phase. From FIG. 2, the metal M phase and the metal Si phase form a layered structure (lamella structure) that overlaps with each other in the thickness cross-sectional direction of the target material, that is, over the boundary region from the surface region to the backing tube. It turns out that it forms.

  FIG. 3 shows a measurement result of a target material of a sputtering target by X-ray diffraction (XRD). For the X-ray diffraction measurement, 2θ-θ measurement was performed using RINT ULITIMA III manufactured by Rigaku Corporation using a Cu-Kα lamp as an X-ray source.

The uppermost graph in FIG. 3 shows an X-ray diffraction pattern obtained by X-ray diffraction measurement of the Si—Cr alloy target material. The second graph from the top shows the Si diffraction peak, the third graph shows the metal Cr diffraction peak, the fourth graph shows the Cr ₅ Si ₃ diffraction peak, and the fifth graph. the diffraction peak of the CrSi is, the graph of the 6-stage, the diffraction peaks of the CrSi ₂ is and the lowermost graph, the diffraction peaks of _Cr 3 Si are shown respectively. Considering both the elemental analysis image shown in FIG. 1 and the X-ray diffraction pattern shown in FIG. 3, the Si—Cr alloy target material has a lamellar structure composed of at least a metallic Si metal phase and a metallic Cr phase. It was confirmed that, when the content of Cr was 33 atomic%, a Cr silicide phase of a Cr ₃ Si phase, a Cr ₅ Si ₃ phase, a CrSi ₂ phase and a CrSi phase was present so as to surround the Cr metal phase. It can be seen that the Cr silicide phase is thin, and the metal Cr phase has a sufficient area.

  In the sputtering target of this embodiment, the target material may be formed directly on the surface of the base material, or may be formed via an intermediate layer. Examples of the material of the intermediate layer include metals such as Mo, Ti, W, Ni, and Cr. These metals may be used alone or in combination of two or more. The intermediate layer may be a single layer or two or more layers.

[Examples 1 to 11] (cylindrical Si-Cr alloy sputtering target)
Si powder and Cr powder having a particle size distribution shown in Table 1 below were prepared. From the frequency distribution measured by Microtrac, the particle size distribution is calculated at the positions where the cumulative frequency is 10% (D10), 30% (D30), 50% (D50), 70% (D70), and 90% (D90). It was determined by reading the particle size. In Table 1, D90-D10 is the difference between the particle diameters of D10 and D90, and D70-D30 is the difference between the particle diameters of D30 and D70.
The above-mentioned Si powder and Cr powder are measured so that the atomic content ratio of Cr with respect to the total atomic weight of Si and Cr becomes the value of the charged amount shown in Table 1 below, and mixed with a rocking mixer for 1 hour to mix. A powder was prepared. The prepared mixed powder was sprayed on the outer periphery of a blasted SUS backing tube (length: 600 mm, diameter: 133 mm) using a plasma spraying machine, and a 5.5 mm thick Si—Cr alloy was sprayed. A target material was formed. The formed Si-Cr alloy target material is machined using a lathe under the conditions that the cutting tool used is a diamond tip, the feed pitch is 0.1 mm / rev, and the number of rotations is 100 times. Was adjusted to be 5.0 mm to produce the cylindrical Si—Cr alloy sputtering targets of Examples 1 to 11.

[Comparative Examples 1-4]
For comparison with the examples, cylindrical Si—Cr alloy sputtering targets of comparative examples 1 to 4 were produced. In Comparative Examples 1 and 4, Si powder and Cr powder shown in Table 1 below were prepared such that the atomic content of Cr with respect to the total atomic weight of Si and Cr became the value of the charged amount shown in Table 1 below. Except for the measurement, the same procedure was used as in the example. Comparative Example 1 has a small amount of charged Cr, and Comparative Example 4 has a large amount of charged Cr.
Comparative Examples 2 and 3 were produced in the same procedure as in the example except that a Cr—Si compound powder was used instead of using the Si powder and the Cr powder. In Comparative Example 2, a Cr-Si compound powder having a Cr content of 10 at% was used, and in Comparative Example 3, a Cr-Si compound powder having a Cr content of 33 at% was used.

  Next, regarding the manufactured cylindrical Si—Cr alloy sputtering targets of Examples 1 to 11 and Comparative Examples 1 to 4, the average value X of the content of the metal element M (Cr), the maximum variation rate thereof, and the thickness direction. Area ratio of metal M (Cr) phase in cross section, shape of metal M (Cr) phase (major axis / minor axis), peak intensity ratio of X-ray diffraction of silicide of metal Si and metal element M (Cr), flexure The strength, the theoretical density ratio, the presence or absence of cracks and chips during machining, and the number of abnormal discharges during sputtering were measured by the following methods. The results are shown in Table 2 below.

<Measurement of the average value X of the content of the metal element M (Cr) and the maximum fluctuation rate thereof>
The sputtering target was divided into five parts along the length in the longitudinal direction. The target material was sampled from each of the five points (if the length of the sputtering target is 600 mm, each point is 150 mm apart). The amount of the metal element M (Cr) in each sampled target material was measured by ICP, and the average of the obtained measured values was defined as the average value X of the metal element M (Cr). Then, the measured value Y having the largest value from the average value X was extracted, and was calculated as the maximum variation rate with respect to the average value X using the following equation. The results are shown in the "Cr content" column of Table 2.
Maximum variation rate (%) = (absolute value of (measured value Y−average value X) / average value X × 100)

<Measurement of area ratio of metal M (Cr) phase in cross section in thickness direction>
An elemental analysis image of a cross section in the thickness direction of the target material of the sputtering target was measured using EPMA. The area of the metal M (Cr) phase was calculated from the measured elemental analysis image, and the area ratio of the metal M (Cr) phase was calculated from the following equation. The results are shown in the "Metal Cr phase area ratio (%)" column in Table 2. In addition, about Comparative Examples 2 and 3, since there was no metal Cr phase, it was described as "-".
Area ratio (%) of metal M (Cr) phase = area of metal M (Cr) phase / measured area of elemental analysis image × 100

<Measurement of shape of metal M (Cr) phase>
An elemental analysis image of a cross section in the thickness direction of the target material of the sputtering target was measured using EPMA. From the measured elemental analysis image, the ratio (long axis / short axis) between the long axis and the short axis of the metal M (Cr) phase was determined, and the average value (L ratio) was calculated. The results are shown in the “Cr shape L ratio” column of Table 2. In addition, about Comparative Examples 2 and 3, since there was no metal Cr phase, it was described as "-".

<Measurement of X-ray diffraction peak intensity ratio of silicide of metal Si and metal element M (Cr)>
After polishing the surface of the target material of the sputtering target, X-ray diffraction was measured. From the obtained X-ray diffraction pattern, and integrated intensity _{I Si} peak (111) plane of the metal Si, silicide phase of the metal element M (Cr), i.e., the _Cr 3 Si (210) plane, _Cr 5 Si ₃ (411) plane, the (111) plane of CrSi ₂ , and the _sum of the integrated intensities of the peaks of the (210) plane of CrSi, I _sum, and the silicide phase of metal element M (Cr) / metal Si : The peak intensity ratio was calculated. The results are shown in the “peak intensity ratio (%)” column of Table 2. In the case of Comparative Example 3, the peak intensity could not be calculated because the metal Si phase was not present, and therefore, it was described as “No Si phase”.
Peak intensity ratio (%) = _Isum / _ISi × 100

<Measurement of bending strength>
As shown in FIG. 4, a test piece having a thickness of 3 mm, a width of 5 mm and a length of 30 mm with respect to the sputtering surface direction was sampled from the target material of the sputtering target, and the sample was used as a fulcrum. A three-point bending test was performed under the conditions of a distance of 20 mm, a test load of 5 kN, and a speed of 0.5 mm / min. The results are shown in the column of "Bending strength (N / mm ² )" in Table 2.

<Measurement of theoretical density ratio>
A test piece was collected from the target material of the sputtering target, and the dimensions and weight of the collected test piece were measured to calculate the density (actually measured value) of the target material.
Next, the theoretical density of the target material was calculated from the following equation.
Theoretical density = 100 / [(% Si content of target material) / (density of Si) + (% content of metal element M (Cr) in target material) / (density of Cr)]
Then, the theoretical density ratio of the target material was calculated from the following equation. The results are shown in the "Theoretical density ratio (%)" column of Table 2.
Theoretical density ratio (%) = density (actual value) / theoretical density × 100

<Measurement of cracking or chipping during machining>
The surface of the sputtering target was visually observed, and it was confirmed whether cracks or chips of 2 mm or more were generated. The results are shown in Table 2 in the column "Crack / Chip During Processing". In addition, the case where this crack / chip did not occur was described as “absent”, and the case where the crack / chip occurred occurred was described as “present”.

<Measurement of the number of abnormal discharges>
A sample sputtering target (target size: diameter 143 mm, length 600 mm) was attached to a sputtering apparatus, Ar was used as a sputtering gas, a sputtering gas pressure was 0.5 Pa, and a sputter output was 5 kW with a direct current (DC) power supply. A sputtering test was performed under the following conditions. The sputtering test was performed continuously for 60 minutes. During this test, the number of abnormal discharges caused by spatter abnormalities was counted using an arc counter attached to the power supply. The results of the measurement are shown in the column of “Number of abnormal discharges” in Table 2. In addition, about the comparative examples 1-4, since the cracking and chipping generate | occur | produced at the time of machining, and it was not able to perform a sputtering test, it was described with "-".

According to the above results, the cylindrical Si-Cr alloy sputtering targets of Examples 1 to 11 had a lamella structure including a metal Si phase and a metal Cr phase formed in the target material, and showed that the metal Si and Cr The peak intensity ratio of X-ray diffraction of silicide was 10% or less, and it was confirmed that the amount of Cr silicide generated was small. In each of Examples 1 to 11, it was confirmed that the area ratio of the metal Cr phase of the target material was 5% or more, and the theoretical density ratio of the target material was 90% or more. Further, in all of Examples 1 to 11, the transverse rupture strength was 40 N / mm ² or more, and there was no occurrence of cracking or chipping during machining.

  In Examples 1 to 9, the number of occurrences of abnormal discharge during sputtering film formation was smaller than those in Examples 10 and 11. This is because, in Examples 1 to 9, the maximum variation rate of the Cr content was within ± 3%, and the composition was more uniform than those in Examples 10 and 11, so that the charge of This is probably because concentration is unlikely to occur.

  On the other hand, in the case of Comparative Example 1, since the amount of the blended Cr powder was small, the amount of the metallic Cr phase generated in the target material was also small, and the transverse rupture strength was not improved. . In the case of Comparative Examples 2 and 3, since the Cr—Si compound was used and the metal Cr phase did not exist in the target material, the bending strength was not improved and cracks occurred during machining. Further, in the case of Comparative Example 4, since the amount of the blended Cr powder was large, a large amount of the Cr silicide phase was generated in the target material, and the amount of the metallic Cr phase was reduced, so that it was difficult to obtain an appropriate lamellar structure. As a result, the brittleness increased, the bending strength was low, and cracks occurred during machining.

[Examples 12 to 16] (cylindrical Si-Zr alloy sputtering target)
Si powder and Zr powder having the particle size distribution shown in Table 3 below were prepared.
The Si powder and the Zr powder were measured so that the atomic content of Zr with respect to the total atomic weight of Si and Zr became the value of the charged amount shown in Table 3 below, and mixed for 1 hour with a rocking mixer to obtain a mixed powder. Was prepared. Using a plasma spraying machine, the prepared mixed powder was sprayed on the outer periphery of a SUS backing tube (length: 600 mm, diameter: 133 mm) which had been subjected to a blast treatment, and a 5.5 mm-thick Si-Zr alloy was sprayed. A target material was formed. Using a lathe, the formed Si-Zr alloy target material is machined under the conditions of a diamond tip, a feed pitch of 0.1 mm / rev, and a rotation speed of 100 times. Was adjusted to be 5.0 mm to produce cylindrical Si-Zr alloy sputtering targets of Examples 12 to 16.

[Comparative Examples 5 to 7]
For comparison with the examples, cylindrical Si-Zr alloy sputtering targets of Comparative Examples 5 to 7 were produced. In Comparative Examples 5 and 7, Si powder and Zr powder shown in Table 3 below were measured such that the atomic content of Zr with respect to the total atomic weight of Si and Zr became the value of the charged amount shown in Table 3 below. Except for the fact that it was taken, it was manufactured by the same manufacturing procedure as that of the example. Comparative Example 5 has a small amount of Zr, and Comparative Example 7 has a large amount of Zr.
Comparative Example 6 was manufactured by the same manufacturing procedure as that of the example except that a Zr-Si compound powder having a Zr content of 10 atom% was used instead of using the Si powder and the Zr powder.

  Next, the same evaluation as in Examples 1 to 11 and Comparative Examples 1 to 4 was performed on the manufactured cylindrical Si-Zr alloy sputtering targets of Examples 12 to 16 and Comparative Examples 5 to 7. The results are shown in Table 4 below.

According to the above results, the cylindrical Si-Zr alloy sputtering targets of Examples 12 to 16 had a lamellar structure including a metal Si phase and a metal Zr phase formed in the target material, and showed that the metal Si and Zr The peak intensity ratio of X-ray diffraction of silicide was 10% or less, and it was confirmed that the amount of Zr silicide generated was small. In each of Examples 12 to 16, it was confirmed that the area ratio of the metal Zr phase of the target material was 5% or more, and the theoretical density ratio of the target material was 90% or more. Further, in all of Examples 12 to 16, the transverse rupture strength was 40 N / mm ² or more, and there was no occurrence of cracks or chips during machining.

  In Examples 12 to 15, the number of occurrences of abnormal discharge during sputtering film formation was smaller than that in Example 16. This is because in Examples 12 to 15, the maximum fluctuation rate of the Zr content was within ± 3%, and the composition was more uniform than that in Example 16, so that the concentration of charges during sputtering was reduced. It is considered that this is because it is unlikely to occur.

  On the other hand, in the case of Comparative Example 5, since the amount of the blended Zr powder was small, the metal Zr phase generated in the target material was also small, and the transverse rupture strength was not improved. . In the case of Comparative Example 6, since the Zr—Si compound was used and the metal Zr phase did not exist in the target material, the bending strength was not improved and cracks occurred during machining. Further, in the case of Comparative Example 7, since the amount of the blended Zr powder was large, a large amount of the Zr silicide phase was generated in the target material, and the metal Zr phase was reduced, so that it was difficult to obtain an appropriate lamellar structure. As a result, the brittleness increased, the bending strength was low, and cracks occurred during machining.

[Examples 17 to 21] (cylindrical Si-Nb alloy sputtering target)
Si powder and Nb powder having a particle size distribution shown in Table 5 below were prepared.
The Si powder and the Nb powder were measured so that the atomic content of Nb with respect to the total atomic weight of Si and Nb became the value of the charged amount shown in Table 5 below, and mixed for 1 hour with a rocking mixer to obtain a mixed powder. Was prepared. Using a plasma spraying machine, the prepared mixed powder was sprayed on the outer periphery of a SUS backing tube (length: 600 mm, diameter: 133 mm) subjected to blast treatment, and a 5.5 mm-thick Si—Nb alloy was sprayed. A target material was formed. The formed Si-Nb alloy target material is machined by using a lathe under the conditions of a diamond bit, a feed pitch of 0.1 mm / rev, and a rotation speed of 100 times. Was adjusted to have a thickness of 5.0 mm to produce cylindrical Si-Nb metal sputtering targets of Examples 17 to 21.

[Comparative Examples 8 to 10]
For comparison with the examples, cylindrical Si—Nb alloy sputtering targets of Comparative Examples 8 to 10 were produced. In Comparative Examples 8 and 10, Si powder and Nb powder shown in Table 5 below were measured such that the atomic content of Nb with respect to the total atomic weight of Si and Nb became the value of the charged amount shown in Table 5 below. Except for the fact that it was taken, it was manufactured by the same manufacturing procedure as that of the example. Comparative Example 5 has a small charged amount of Nb, and Comparative Example 10 has a large charged amount of Nb.
Comparative Example 9 was manufactured by the same manufacturing procedure as that of the example except that an Nb-Si sintered body powder having an Nb content of 10 atomic% was used instead of using the Si powder and the Nb powder. .

  Next, the same evaluation as in Examples 1 to 11 and Comparative Examples 1 to 4 was performed on the manufactured cylindrical Si—Nb alloy sputtering targets of Examples 17 to 21 and Comparative Examples 8 to 10. The results are shown in Table 6 below.

According to the above results, the cylindrical Si-Nb alloy sputtering targets of Examples 17 to 21 had a lamellar structure including a metal Si phase and a metal Nb phase formed in the target material, and showed that the metal Si and Nb The peak specific intensity ratio of the X-ray diffraction of silicide was 10% or less, and it was confirmed that the generation amount of the Nb silicide phase was small. In all of Examples 17 to 21, it was confirmed that the area ratio of the metal Nb phase of the target material was 5% or more, and the theoretical density ratio of the target material was 90% or more. Further, in all of Examples 17 to 21, the transverse rupture strength was 40 N / mm ² or more, and no cracking or chipping occurred during machining.

  In Examples 17 to 20, the number of occurrences of abnormal discharge during sputtering film formation was smaller than that in Example 21. This is because the maximum fluctuation rate of the Nb content was within ± 3% in Examples 17 to 20 and the composition was more uniform than that in Example 21. This is probably because concentration is unlikely to occur.

  On the other hand, in the case of Comparative Example 8, since the amount of the Nb powder blended was small, the metal Nb phase generated in the target material was also small, and the transverse rupture strength was not improved. . In the case of Comparative Example 9, since the Nb-Si sintered body was used and the metal Nb phase was not present in the target material, the bending strength was not improved and cracks occurred during machining. Further, in the case of Comparative Example 10, since the amount of the Nb powder blended was large, a large amount of the Nb silicide phase was generated in the target material, and the metal Nb phase was reduced, so that it was difficult to obtain an appropriate lamellar structure. As a result, the brittleness increased, the bending strength was low, and cracks occurred during machining.

[Examples 22 to 27] (cylindrical Si-metal element M alloy sputtering target)
A Si powder and a metal element M powder having a particle size distribution shown in Table 7 below were prepared.
The Si powder and the powder of the metal element M are measured so that the atomic content of the metal element M with respect to the total atomic weight of the Si and the metal element M becomes the value of the charged amount shown in Table 7 below, and is measured with a rocking mixer. The mixture was mixed for 1 hour to prepare a mixed powder. The prepared mixed powder is sprayed on the outer periphery of a blasted SUS backing tube (length: 600 mm, diameter: 133 mm) using a plasma spraying machine to form a 5.5 mm thick Si-metal element. An M alloy target material was formed. Using a lathe, the formed Si-metal element M alloy target material is machined under the conditions of a diamond tool, a feed pitch of 0.1 mm / rev, and a rotation speed of 100 times, to thereby obtain a Si-metal element. By adjusting the thickness of the M alloy target material to be 5.0 mm, the cylindrical Si-metal element M alloy sputtering targets of Examples 22 to 27 were produced.

  Next, the same evaluation as in Examples 1 to 11 and Comparative Examples 1 to 4 was performed on the manufactured cylindrical Si-metal element M alloy sputtering targets of Examples 22 to 27. The results are shown in Table 8 below.

According to the above results, the cylindrical Si-metal element M alloy sputtering targets of Examples 22 to 27 had a lamella structure including a metal Si phase and a metal M phase formed in the target material, and the metal Si The peak ratio intensity ratio of the X-ray diffraction of the silicide compound of metal and the metal element M was 10% or less, and it was confirmed that the amount of silicide generated was small. In all of Examples 22 to 27, it was confirmed that the area ratio of the metal Nb phase of the target material was 5% or more, and the theoretical density ratio of the target material was 90% or more. Further, in all of Examples 17 to 21, the transverse rupture strength was 40 N / mm ² or more, and no cracking or chipping occurred during machining.
In all of Examples 22 to 27, the maximum variation rate of the metal element M content was within ± 3%, and the number of abnormal discharges during sputtering film formation was small.

  As described above, in the sputtering targets of Examples 1 to 27, as the target material, the metal layer containing the metal element M in the range of 8 to 66 atomic% and the balance containing Si and the unavoidable impurities was used. The metal layer has a lamellar structure composed of at least a metal Si phase and a metal M phase, and has a peak ratio between the X-ray diffraction intensity of the metal Si and the silicide of the metal element M (the metal element). It was confirmed that the content of (silicide compound of M) / (metallic Si) was 10% or less, and the brittleness of the target material could be improved and the transverse rupture strength was improved. It was found that the occurrence of cracks and chips during machining of the target using a lathe can be reduced.

In the above-described embodiment, the target material is formed on the outer periphery of the cylindrical backing tube by the thermal spraying method. However, the target material may be formed on the surface of the flat backing plate by the thermal spraying method. Also in this case, similarly to the embodiment, it is possible to form a target material having a lamellar structure composed of at least a Si metal phase and a metal M phase.
Note that the technical scope of the present invention is not limited to the above-described embodiment, and various changes can be made without departing from the spirit of the present invention.

Claims (10)

Including a base material and a target material formed on the surface of the base material,
The target material contains the metal element M in a range of 8 atomic% or more and 66 atomic% or less, and has a composition including a balance of Si and unavoidable impurities,
Having a metal M phase and a metal Si phase,
In X-ray diffraction, the ratio I _sum / I _Si × 100 of the integrated intensity I _Si of the peak on the (111) plane of the metal Si and the sum I _sum of the integrated intensity of the peak of each silicide compound represented by M _x Si _y. Is not more than 10%.   The sputtering target according to claim 1, wherein the target material has an area ratio of the metal M phase in a cross section in a thickness direction of 5% or more.   3. The sputtering according to claim 1, wherein in the target material, an average value of a length ratio between a major axis and a minor axis of the metal M phase in a thickness direction cross section is 2.0 or more. 4. target. 4. The sputtering target according to claim 1, wherein the target material has a bending strength of 40 N / mm ² or more. 5.   The sputtering target according to any one of claims 1 to 4, wherein the target material has a theoretical density ratio of 90% or more.   In the above-mentioned target material, the content of the metal element M in each part of the target material is within ± 3 atomic% with respect to the average value X of the content of the metal element M in the entire target material. The sputtering target according to any one of claims 1 to 5.   The sputtering target according to any one of claims 1 to 6, wherein the metal element M is a high melting point metal element having a melting point higher than the melting point of metal Si.   The sputtering target according to claim 7, wherein the refractory metal element is at least one metal element selected from the group consisting of Co, Cr, Mo, Ni, Nb, Ta, Ti, W, and Zr. A method for producing a sputtering target in which a base material is sprayed by using a mixed powder composed of a powder of a metal element M and a powder of a metal Si to form a target material on the surface of the base material . A method for manufacturing a sputtering target, wherein the difference between the particle diameters at the cumulative frequencies D10 and D90 in the respective particle size distributions of the powder and the metal Si powder is within 150 μm . 10. The sputtering target according to claim 9, wherein, in each particle size distribution of the powder of the metal element M and the powder of the metal Si, the difference between the particle diameters at the cumulative frequencies D30 and D70 is within 50 μm. 11. Production method.