JP3386677B2 - Metal silicide target material - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal silicide target material used for electrode formation or wiring formation for semiconductor devices.

[0002]

2. Description of the Related Art With the recent high integration of LSI, LSI
A metal silicide film typified by a tungsten silicide film or a molybdenum silicide film is used for the electrodes and wirings. As a method for forming these silicide films, a sputtering method, a chemical vapor deposition method and the like are used, and the sputtering method is predominant in view of film productivity, reproducibility and work safety. This sputtering method is a method in which an inert gas ion such as argon is made to collide with the surface of the target material using a target material composed of metal and silicon to form fine particles emitted as a thin film. A specific target material composition is stoichiometric metal silicide MSi ₂
Since a large stress is applied to the metal silicide film to be formed when the above composition is used, a target material having a composition in which silicon is higher than the stoichiometric composition is usually used within a range where the sheet resistance does not increase.

In the above-mentioned target material,
In order to prevent cracking during use, to ensure uniformity of thin film, low resistance, etc., or to prevent generation of particles due to local discharge during sputtering, high density of impurities A method of manufacturing a small amount of target material is being studied. For example, JP-A-61-145
Japanese Patent No. 828 discloses a method in which a high-purity high-melting point metal powder and a high-purity silicon powder are mixed, pressure-molded and heat-sintered to obtain a sintered body, and then electron beam melting is performed to obtain a silicide-melted product. ing. Further, in JP-A-61-1141673 or JP-A-61-1141674, a method of obtaining a sintered body by hot pressing after mixing molybdenum powder or tungsten powder, molding and silicidation, and then crushing pellets To obtain a high-density target material.

Further, as disclosed in Japanese Patent Laid-Open No. 63-219580, a refractory metal powder such as molybdenum or tungsten and a silicon powder are subjected to a silicidation reaction in a vacuum to obtain a fine structure. A method of hot isostatically pressing the obtained calcined body has also been proposed. In addition, special fair 6
As described in JP-A-41629, paying attention to the fact that the amount of carbon is related to the reduction of particles, after producing a mixed powder of metal powder and silicon powder, in a high vacuum in order to reduce carbon and oxygen. Also disclosed is a method of adding a step of heating to reduce carbon and oxygen. Also,
As described in JP-A-8-49068, the applicant of the present invention uses a calcined body at a temperature of 1200 ° C. to 140 ° C. to improve the density.
A method is proposed in which the relative density is 101% or more by sintering at a high temperature of 0 ° C. and 110 MPa or more and a high pressure.

[0005]

The above-mentioned densification, reduction of impurities and refinement of structure are effective methods for reducing particles of a metal silicide target material such as molybdenum silicide or tungsten silicide. However, the high integration of LSIs in recent years has been remarkable, and the width of the thin film required for wiring has become submicron. With this, finer particles, which have not been a problem in the past, are also regarded as problems. It's coming. The above-mentioned Japanese Patent Laid-Open No. 8-4 proposed by the applicant.
When the target material was manufactured by the method described in Japanese Patent No. 9068 and the amount of particles generated was investigated, it was found to be 0.3 μm.
It was confirmed that the above particles were greatly reduced. However, it was found that the evaluation could not be sufficiently reduced in some cases when the number of generated particles of 0.2 μm or more was evaluated more severely. The present invention is to provide a novel metal silicide target material capable of effectively suppressing the generation of particles having particularly small particle diameters in order to meet the above-mentioned requirements.

[0006]

DISCLOSURE OF THE INVENTION The inventor of the present invention has as a basic target material a structure in which the atomic ratio Si / M of silicon and metal M is 2 or more and the structure is essentially composed of metal silicide and free silicon. On the other hand, the method of suppressing particles by increasing the density of the target material alone is not sufficient to suppress the generation of particles with small particle diameters, and it is necessary to add new means to increase the density. The relationship between the material structure and the generation of particles was examined in detail. As a result, it was found that the generation of the particles having a small particle size depends on the internal state such as strain and dislocation of the structure forming the target material, particularly the internal state of free silicon. Then, the present inventor first pays attention to the hardness of the free silicon portion as a characteristic that reflects the internal state of the free silicon, and by lowering the hardness of the free silicon portion, it is possible to suppress particles with a small particle size. The inventors have found out that there has been reached the present invention.

That is, according to the present invention, the target materials are stoichiometric refractory silicide MSi ₂ and pure silicon Si.
The metal silicide target has a relative density of more than 100%, which is the ratio of the true density of the target material to the theoretical density calculated assuming that the target material has a Vickers hardness of less than 1100, in the structure of the target material. It is a material.

Further, the present inventor has focused on the density of dislocations existing in the structure of the free silicon portion as an index directly representing the internal state of the free silicon. Then, it was found that reducing dislocations confirmed in the free silicon structure is effective in reducing particles having a small particle size.

The target material of the present invention viewed from the dislocation density is a high melting point silicide MS whose target material is stoichiometric.
i ₂ and the relative density, which is the ratio of the true density of the target material to the theoretical density calculated assuming that it is composed of pure Si, exceeds 100%, and dislocations occur in the free silicon portion existing in the target material structure. The size of the region in which is not confirmed is a metal silicide target material having a diameter of 1 μm or more. At this time, the Vickers hardness of the free silicon portion in the target material structure is preferably less than 1100.

In the above-mentioned target material of the present invention ,
The Vickers hardness of the metal silicide portion of the data Getto material in the tissue is less than 1200. The target material of the present invention uses a diamond indenter for Rockwell hardness A scale, and has a scratch rate of 10 mm / min and a load rate of 100.
When the load is continuously increased from 0 [N] at [N / min],
Load indicating the destruction Ru der more than 50N.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, in order to suppress the generation of coarse particles, first, the relative density is 100%.
It is necessary to adjust to a high density exceeding. This is because the voids present in the target material having a low density are likely to cause abnormal discharge during sputtering and cause generation of coarse particles. In such a high-density target material, in order to prevent the generation of particles with a small particle diameter, the internal conditions such as strain and dislocation of the structure of the target material, especially the internal conditions of free silicon, are specified. There are important features of the invention. The details will be described below.

As a condition for producing the target material, the inventor of the present invention examined the target material in which the raw material particle diameter and the pressure sintering conditions were variously changed and the generation of particles having a small particle diameter. As a result, it has been found that there is a target material in which the generation of small-sized particles is small even if the microstructures have no apparent difference. After examining the cause in detail, it was found that the hardness of the free silicon part is significantly lower in the target material with less particles compared to the target material with many particles with small particle size. is there. In the present invention, the hardness of the free silicon part is defined as the Vickers hardness of the free silicon part is less than 1100. In the present invention, the Vickers hardness is set to less than 1100, because the range can obviously improve the generation of particles having a small particle diameter as compared with the conventional high density material.

When the structure of the target material was further examined, when the target material with few particles was observed with a transmission electron microscope, it was found that the free silicon portion had less strain, stacking faults or dislocations than the target material with many particles. found. That is, the hardness of the free silicon portion described above reflects the internal state of such a tissue. In the present invention, in order to more clearly express the above-mentioned target material, it has been defined that the size of the region where dislocation is not confirmed is 1 μm or more in the free silicon portion existing in the target material structure. It is difficult to quantify internal states such as strain and dislocation, and in order to quantitatively evaluate dislocations that are relatively easy to confirm, the size is defined by the size of the region where dislocations are not confirmed.

A specific description will be given of a target material of tungsten silicide having a composition of WSix x = 2.75. 1 and 2
Are 100,000 and 30,000 times transmission electron micrographs of the free silicon portion of the tungsten silicide of the present invention having a relative density of 102%, in which black particles are tungsten silicide portions and white portions are free silicon portions. It is a department. On the other hand, FIGS. 3 and 4 show the relative density 1 of the comparative example.
2 is transmission electron micrographs of 100,000 and 30,000 times observation of a free silicon portion of 02% tungsten silicide.

In FIG. 1 and FIG. 2, an image which seems to be a twin crystal is observed, but an image showing the existence of a clear dislocation is not recognized. On the other hand, in FIGS. 3 and 4, dislocations that seem to be innumerable are confirmed. When compared with the target material of the present invention shown in FIGS. 1 and 2, the dislocation density of the silicon portion is obviously higher in the comparative example. In order to quantify the magnitude of this dislocation density, the size is determined by the size of the region in which dislocation is not confirmed. That is, in the structures shown in FIGS. 1 and 2, the size of the region where dislocation is not confirmed is 1 μm in diameter.
However, in the structures shown in FIGS. 3 and 4, the diameter of the region where dislocation is not confirmed is 0.5 at the maximum.
μm or less. Due to such a difference in structure, the number of particles of 2 μm or more generated in the tungsten silicide material of the present invention is 1/3 that of the target material of the comparative example.
It became possible to:

The target material of the present invention, which has a low hardness of the free silicon portion and a low dislocation density, has a mean particle size of 50 μm or less, for example, a metal powder that forms metal silicide, such as a metal powder of tungsten or molybdenum. An extremely fine silicon powder having a diameter of 5 μm or less was used as a raw material powder, which was heated to cause a silicidation reaction to form a calcined body, which was further pulverized and then 1200 ° C. or higher, 4
It can be obtained by sintering at 0 MPa or more and 100 MPa or less. By using such a fine raw material powder, the relative density can be made higher than 100% without applying a high pressure of 110 MPa or more, and the hardness of the free silicon portion can be 11 in Vickers hardness.
The target material of the present invention of less than 00 can be obtained.

Further, as a method for simply adjusting the density to a high density, there is a method described in Japanese Patent Laid-Open No. 8-49068.
Conditions of high temperature of 200 ° C. or higher and high pressure of more than 100 MPa can be applied. However, this method is not preferable because a high pressure is applied and the hardness of the free silicon portion in the target material structure becomes Vickers hardness (Hv) of 1100 or more and the dislocation density becomes high. Therefore, when adopting this method, it is necessary to reduce the hardness of the free silicon portion by performing an annealing treatment that is held at 1200 ° C. or higher, for example. In the target material structure of the present invention, since the free silicon portion is surrounded and constrained by the metal silicide, the hardness of the free silicon portion is reduced to a small extent even if the above-mentioned annealing treatment is performed. Therefore, it is preferable to adopt the above-described method of sintering at a low pressure.

In the case where the metal silicide target material in which silicon exists as free silicon as in the present invention is to be obtained by pressure sintering, the relative density is 1200 ° C. in order to obtain a density of more than 100%. It is preferable to apply the above temperature. The upper limit of the temperature is the melting point of Si (14
1400 ° C. or lower, which is lower than 14 ° C.) is desirable. this is,
This is because when the temperature exceeds 1400 ° C., silicon melts and the sintered body structure becomes nonuniform. Further, according to the study by the present inventors, the Vickers hardness of the free silicon portion increases almost in proportion to the sintering pressure. In the present invention, the Vickers hardness is 11
In order to make it less than 00, it is desirable to set the sintering pressure to 100 MPa or less.

In the present invention, it is defined that the atomic ratio Si / M of silicon and refractory metal exceeds 2 is Si.
This is because when / M is 2 or less, it becomes a target material of the structure in which the free silicon region does not exist, and particles due to the hardness of the free silicon portion or the dislocation density are not generated. When used as an LSI electrode or wiring, there is a problem that the sheet resistance becomes high when Si / M exceeds 4, so Si / M is preferably 4 or less. In addition, the larger the amount of free silicon, the more particles are generated due to the hardness or dislocation density of the free silicon portion. Therefore, the present invention is more effective for a target material having Si / M of 2.5 or more. .

Further, the cause of the influence of the hardness and dislocation density of the free silicon portion of the present invention on the generation of particles having a small particle size is unknown, but the present inventor has found that the sputtered surface of the target material is fragile. I have identified the cause. According to the study by the present inventors, in the scratch test in which a simple load is applied to the sputter surface of the target material,
It was recognized that the target material of the comparative example having many particles tended to have a wider scratch width. In order to quantify this, a so-called acoustic
The method of measuring emission was adopted.

Specifically, using a diamond indenter for Rockwell hardness A scale, the scratching speed is 10 mm /
It has been found that when the load continuously increases from 0 [N] at a load load speed of 100 [N / min] and the load indicating fracture is 50 N or more, the generation of small particle size particles can be greatly reduced. . In the actual measurement, the scratch breaking load due to acoustic emission was detected as a relative value. An example thereof is shown in FIG. In FIG. 9, when the load is increased, the point at which the detected value jumps up is detected as a scratch breaking load (see FIG. 9) except for the initial variation in the detected value. The vertical axis of FIG. 9 is a relative detection value. In the present invention, a diamond indenter for Rockwell hardness A scale is used in order to reduce particles from the relationship between the scratch breaking load and the generation of particles having a small particle diameter, the scratch speed is 10 mm / min, and the load speed is 1
When the load is continuously increased from 0 [N] at 00 [N / min],
Load indicating the destruction has been found that you and more than 50N.

When manufacturing the target material of the present invention,
A silicidation reaction can be used. This reaction is a reaction in which molybdenum, tungsten, or the like reacts with silicon to form a metal silicide. Stoichiometric composition MSi ₂ ,
That is, when the atomic ratio Si / M between silicon and metal M is adjusted to be more than 2 in excess of silicon, a silicide reaction results in a structure in which metal silicide and free silicon that has not reacted are present. In the present invention, the theoretical density is obtained on the assumption that stoichiometric metal silicide MSi ₂ and pure silicon Si exist independently in the target material structure. The specific method of calculation is as described later.

The target material structure of the present invention is composed of the compound metal silicide and free silicon as described above. Therefore, as the structure, specifically, the composite phase shown in the case where M is tungsten (FIG. 5) or the case where M is molybdenum (FIG. 7) shown in the examples is formed. As shown in FIGS. 5 and 7, it is composed of a white portion corresponding to metal silicide and a dark color portion or black portion corresponding to free silicon. In the target material structure of the present invention shown in FIGS. 5 and 7, the free silicon portion is finely dispersed in the structure with an equivalent circular diameter of 5 μm or less. As a result, a target material having a high density exceeding 100% relative density is realized.

In the present invention, the theoretical density can be calculated as follows. Atomic ratio of silicon and tungsten Si / W =
For the 2.75 target material, the stoichiometric tungsten silicide WSi ₂ has the following density and molecular weight: Density 9.83 [g / cm ³ ] Molecular weight 240.022 [g / g-mol] The density and molecular weight of pure silicon are as follows. Density 2.33 [g / cm ³ ] Molecular weight 28.086 [g / g-mol]

The target material is substantially WSi ₂ : 1 [g-mo
l] and Si: 0.75 [g-mol] only, the target material weight is (1 [g-mol] × 240.022 [g / g-mol]) + (0.75 [g-mol] × 28.086
[g / g-mol]) = 261.85 [g] Target material volume is (1 [g-mol] × 240.022 [g / g-mol] /9.83 [g / cm ³ ]) + (0.75 [gm
ol] × 28.086 [g / g-mol] /2.33 [g / cm ³ ]) = 33.458 [cm ³ ]

The density at this time is target material weight / target material volume = 7.803 [g / cm ³ ]. This is the theoretical density. On the other hand, the true density can be obtained by determining the volume of the target material by the Archimedes method, and by weighing the target material. If the true density obtained by this is, for example, 7.90 [g / cm ³ ], the relative density is (true density × 100) / theoretical density = (7.90 [g / cm ³ ] × 100)
/7.803 [g / cm ³ ] = 101.2%.

[0027]

【Example】

(Example 1) High-purity tungsten powder (purity 99.999% or more, average particle size 4.8 μm) and high-purity silicon powder (purity 99.9%)
99% or more, average particle size 2 μm) were weighed in a compounding ratio of Si / W = 2.75 and mixed with a blender. The theoretical density at this time is 7.803 [g / cm ³ ] when calculated by the above method. The mixed powder obtained by mixing was subjected to silicidation reaction under a high vacuum of 6 × 10 −2 square Pa or less under the condition of 1350 ° C. × 2 hr to obtain a calcined body. This calcinated body is 100 mesh (150μ
m) crushed to below, crushed powder is pressed and sintered by hot isostatic pressing under the conditions shown in Table 1, and machined to 300 mm
A φ tungsten target material was obtained. The true density was obtained by the Archimedes method. Table 1 shows the relative density calculated from the obtained true density and theoretical density.

[0028]

[Table 1]

The hardness of the free silicon portion and the metal silicide portion of the obtained target material was determined by a Vickers hardness meter with a load of 50 kg. In addition, the target material surface,
Using a diamond indenter for Rockwell hardness A scale, scratch speed 10 mm / min, load speed 100 [N /
Minute], a scratch test in which the load is continuously increased from 0 [N] was performed, and a load indicative of fracture (scratch fracture load) was detected by acoustic emission. 00
The size of the region in which dislocations were not confirmed was observed by observing the structure at 0x
(Dislocation-free area diameter) was observed. Then, the obtained tungsten silicide target material was sputtered under the conditions shown in Table 3 to measure the number of particles of 0.3 μm or more and 0.2 μm or more generated on a 6-inch wafer. The results are shown in Table 2.

[0030]

[Table 2]

[0031]

[Table 3]

FIG. 5 shows a 400 times structure photograph as a typical structure of the tungsten silicide target material of the present invention. In the tungsten silicide target material of the present invention shown in FIG. 5, what is shown in white is a tungsten silicide part which is a compound, what is seen in black is a free silicon part, and these have a dispersed structure. Of the samples shown in Table 1 and Table 2, Samples 1 to 6 are target materials of the present invention, and Samples 7 to 10 are
Is the target material of the comparative example.

From the data shown in Tables 1 and 2, a diagram in which the relationship between the pressure sintering pressure in the hot isostatic press and the hardness of the obtained Si and WSi ₂ portions of the target material is summarized is shown in FIG. Show. As shown in FIG. 6, as the pressure sintering pressure is increased, the hardness of the Si portion and the WSi ₂ portion is proportionally increased. For example, at a pressure sintering pressure of 180 MPa, the hardness of the Si portion is 1500 Hv and the hardness of WSi ₂ is 1210.
Has reached Hv. In addition, as shown in FIG.
It can be seen that the increase in hardness of the part is more remarkable than the increase in hardness of WSi ₂ . As shown in Table 2, the target materials of the present invention in which the hardness of the free silicon region was suppressed to less than 1100 in Vickers hardness were compared with the target materials of Comparative Examples 7 to 9 having Vickers hardness of 1200 or more. It can be seen that the particles with a small particle size were significantly reduced.

Further, as shown in Table 2, looking at the scratch breaking load evaluated by acoustic emission, it can be seen that the lower the scratch breaking load, the more the generation of particles of small particle size. .
All of the target materials of the present invention in which small particles having a small particle diameter are not generated have a scratch breaking load of 50 N or more.

Observation of dislocations with a transmission electron microscope has confirmed that the target material in which small-sized particles are rarely generated has few dislocations in free silicon portions. In the target material of the present invention, the area diameter in which dislocations were not confirmed was as wide as 1 μm or more, but in the target material of the comparative example in which many small particle size particles were generated, the area diameter without dislocation was 0.5 μm or less. there were. Since the sample 10 of the target materials of the comparative example was sintered at a low temperature, the relative density was only 98.8% and the dislocation-free region was wide, but the generation of particles increased overall. It was not desirable.

Example 2 High-purity molybdenum powder (purity
99.999% or more, average particle size 4.2 μm) and high-purity silicon powder (purity 99.999% or more, average particle size 2 μm) were weighed in a mixing ratio of Si / Mo = 2.3 and mixed with a blender. The theoretical density at this time is 5.734 [g / cm ³ ] when calculated by the above method. The mixed powder obtained by mixing is 6 × 10 under the condition of 1250 ° C × 4hr.
A silicidation reaction was performed under a high vacuum of minus square Pa or less to obtain a calcined body. This calcined body was crushed to 100 mesh (150 μm) or less in an argon atmosphere, and the crushed powder was pressure-sintered by hot isostatic pressing under the conditions shown in Table 3 and a 300 mmφ molybdenum silicide target material was machined. Obtained. The true density was obtained by the Archimedes method. Table 4 shows the relative density calculated from the obtained true density and theoretical density.

[0037]

[Table 4]

The hardness of the free silicon portion and the metal silicide portion of the obtained target material was determined by a Vickers hardness meter with a load of 50 kg. Also, the target material surface is scratched at a speed of 10 mm / with a diamond indenter for Rockwell hardness A scale.
Min, a load test was carried out by continuously increasing the load from 0 [N] at a load speed of 100 [N / min], and the load indicating the fracture (scratch fracture load) was detected by acoustic emission. In the field of view, the structure was observed with a transmission electron microscope at a magnification of 30,000 to observe the size of a region where dislocation was not confirmed (dislocation-free area diameter). Then, the obtained molybdenum silicide target material is sputtered under the conditions shown in Table 3 to generate 0.3 on a 6-inch wafer.
The number of particles of μm or more and 0.2 μm or more was measured. The results are shown in Table 5.

[0039]

[Table 5]

FIG. 7 shows a 400 times structure photograph of a typical structure of the molybdenum silicide target material of the present invention. In the molybdenum silicide silicide target material of the present invention shown in FIG. 7, white is a molybdenum silicide part which is a compound, and black is a free silicon part, which has a dispersed structure. . It can be seen that, compared to the tungsten silicide target material of Example 1, Si / Mo = 2.3, which is a small amount of Si, and therefore the volume of free silicon occupying the structure is small. Of the samples shown in Tables 4 and 5, Samples 11 to 16 are target materials of the present invention, and Samples 17 to 20 are target materials of Comparative Examples.

From the data shown in Tables 4 and 5, the relationship between the pressure sintering pressure in the hot isostatic press and the hardness of the Si portion and MoSi ₂ portion of the obtained target material is summarized in FIG. Show. As shown in FIG. 8, as the pressure sintering pressure is increased, the hardness of the Si portion and the MoSi ₂ portion increases proportionally. For example, at a pressure sintering pressure of 180 MPa, the hardness of the Si portion is 1226 Hv and that of MoSi ₂ is 1.
It has reached 097 Hv. As shown in FIG. 6, it can be seen that the increase in the hardness of the Si portion is particularly larger than the increase in the hardness of MoSi ₂ . It is speculated that in this molybdenum silicide target material, the hardness of the Si portion was not so high as that of the tungsten silicide target material of Example 1 due to the small amount of Si, which is Si / Mo = 2.3. As shown in Table 4, the target materials of the present invention in which the hardness of the free silicon region was suppressed to less than 1100 in Vickers hardness were compared with the target materials of Samples 17 to 19 of Comparative Examples having Vickers hardness of 1100 or more. It is possible to reduce small particle size.

Further, as shown in Table 5, looking at the scratch breaking load evaluated by acoustic emission, it is found that the lower the scratch breaking load, the more the generation of particles having a small particle size. .
All of the target materials of the present invention in which small particles having a small particle diameter are not generated have a scratch breaking load of 50 N or more.

Observation of dislocations by a transmission electron microscope has confirmed that even in the molybdenum silicide target material, the target material in which the generation of small-sized particles is small, has few dislocations in the free silicon portion.
In the target material of the present invention, the area diameter in which dislocations were not confirmed was as wide as 1 μm or more, but in the target material of the comparative example in which particles with small particle diameters were frequently generated, the area diameter without dislocation was less than 1 μm. It was a thing. Since the sample 20 of the target materials of the comparative example was sintered at a low temperature, the relative density was only 98.5% and the dislocation-free region was wide, but the generation of particles increased overall. It was not desirable.

[0044]

According to the present invention, the hardness of the free silicon portion is reduced or the amount of dislocations existing in the free silicon portion is reduced with respect to the metal silicide target material whose relative density is adjusted to a high density of 100% or more. Reduced metal silicide part
By lowering the hardness and increasing the scratch breaking load, it is possible to suppress the generation of particles having a smaller particle diameter, which was difficult to reduce in the past . Therefore, by using the target material of the present invention, the manufacturing yield of semiconductor devices that require finer processing accuracy or the reliability of semiconductor devices can be improved, which is extremely effective in industry.

[Brief description of drawings]

FIG. 1 is a microstructure photograph of a target material structure of the present invention by a transmission electron microscope at a magnification of 100,000.

FIG. 2 is a photograph of a microstructure of a target material structure of the present invention, taken with a transmission electron microscope at a magnification of 30,000.

FIG. 3 is a microstructure photograph of a target material structure of a comparative example taken with a transmission electron microscope at a magnification of 100,000.

FIG. 4 is a microstructure photograph of a target material structure of a comparative example with a transmission electron microscope at a magnification of 30,000.

FIG. 5 is a microstructure photograph showing an example of the structure of the tungsten silicide target material of the present invention.

FIG. 6 is a diagram showing the relationship between the pressure sintering pressure of the tungsten silicide target material and the hardness of the free silicon portion.

FIG. 7 is a microstructure photograph showing an example of the structure of the molybdenum silicide target material of the present invention.

FIG. 8 is a diagram showing the relationship between the pressure sintering pressure of the molybdenum silicide target material and the hardness of the free silicon portion.

FIG. 9 is a diagram showing an example of measuring a breaking load by acoustic emission.

Claims (3)

(57) [Claims] 1. A target material having an atomic ratio Si / M of silicon and metal M of 2 or more, and having a texture composed of metal silicide substantially as a compound and free silicon, wherein the target material is stoichiometric. The relative density, which is the ratio of the true density of the target material to the theoretical density calculated assuming that it is composed of the refractory silicide MSi ₂ and pure silicon Si, exceeds 100%, and the Vickers of the free silicon portion in the target material structure hardness Ri der less than 1100, Target
The Vickers hardness of the metal silicide part in the structure of the alloy is 1
Less than 200, for Rockwell hardness A scale
Using diamond indenter, scratching speed 10mm / min, negative
Continuous load from 0 [N] at load speed of 100 [N / min]
When increased heavy metal Shirisaidota load showing the destruction, characterized in der Rukoto least 50 N - target material. 2. A target material having an atomic ratio Si / M of silicon and metal M of 2 or more, and having a texture composed of metal silicide that is substantially a compound and free silicon, wherein the target material is stoichiometric. The relative density, which is the ratio of the true density of the target material to the theoretical density calculated assuming that it is composed of the refractory silicide MSi ₂ and pure silicon Si, exceeds 100%, and the free silicon portion existing in the target material structure is There are, size of the area dislocation is not confirmed Ri der more in diameter 1 [mu] m, the metal of the target material in the tissue sheet
Vickers hardness of the rear part is less than 1200,
Uses a diamond indenter for Rockwell hardness A scale
Scratch speed 10 mm / min, load speed 100 [N
/ Min], when the load is continuously increased from 0 [N],
Metal silicide target material load indicating a corrupted is characterized der Rukoto least 50 N. 3. The metal silicide target material according to claim 2, wherein the free silicon portion in the target material structure has a Vickers hardness of less than 1100.